B1 Means of escape in case of fire

B1 Means of escape in case

A building shall be so designed and constructed that there are
of fire. adequate means of escape in case of fire from the building to a place of safety outside the building, capable of being safely and effectively used.

Performance

The requirement of B1 may be met:

(a) if there are routes of sufficient number and size, which are suitably located, to enable persons to escape to a place of safety in the event of fire;

(b) if the routes are sufficiently protected from the effects of fire in terms of enclosure, where necessary, and in the use of materials on the routes; and

(c) if sufficient lighting, means of smoke control and an alarm system to warn the occupants of the existence of fire are provided to enable them to use the routes safely;

all to an extent necessary that is dependent on the use of the building, its size and height.

1.1 Means of Escape Provisions for Different Purpose Groups
and Building Types

Purpose Groups 1(a) and 1(b)

Dwelling Houses

1.1.1 Guidance on means of escape in dwelling houses, Purpose Group 1(a) and 1(b), including provisions for conversion of lofts in houses to habitable accommodation, is provided in:

• Sub-section 1.5 (dwelling houses) of this Technical Guidance Document.

Purpose Group 1(c)

Flats and Maisonettes

1.1.2 Guidance on the provision of means of escape in buildings containing flats and maisonettes, etc. Residential(Dwellings), Purpose Group 1(c), is provided in the following:

• BS 5588: Part 1: 1990, Fire precautions in the design, construction and use of buildings, Part 1, Code of practice for residential buildings;

and

• Sub-sections 1.4 (general provisions for means of escape), 1.6 (open plan flats), 1.7 (protected corridors / lobbies serving all flats), and 1.8 (domestic sprinkler systems), of this Technical Guidance Document.

Section three of BS 5588: Part 1 1990, contains recommendations in relation to the internal planning of flats and maisonettes, escape routes from dwellings with corridor, lobby or open balcony approach and vertical escape routes by way of common stairways. Recommendations are also included for stairways in buildings which contain dwellings and other uses (mixed user buildings).

Section five of BS 5588: Part 1: 1990, contains recommendations in relation to accommodation ancillary to flats and maisonettes.

Purpose Group 2(a) (Part)

Hospitals

1.1.3 Guidance on the provision of means of escape in hospitals is provided in the following:

• Firecode Health Technical Memorandum 81, Fire precautions in new hospitals, 1996 (HTM 81: 1996)

Hospitals, in particular, require that evacuation procedures be given special consideration in the design of the means of escape. The principle of progressive horizontal evacuation is particularly relevant. Guidance on progressive horizontal evacuation and the provision of compartmentation for this purpose is contained in Chapters 3 and 5 of HTM 81: 1996. Compartmentation is also required for the purpose of satisfying the requirements of regulation B3 - Internal fire spread (structure) and guidance on this is contained in 3.2 of this Technical Guidance Document.

Purpose Group 3

Offices

1.1.4 Guidance on the provision of means of escape in offices is provided in the following:

• BS 5588: Part 11: 1997, Fire precautions in the design, construction and use of buildings, Part 11. Code of practice for shops, offices, industrial, storage and other similar buildings; and
• Sub-section 1.4 (General Provisions for means of escape) of this Technical Guidance Document. Section 3 of BS 5588: Part 11: 1997, contains recommendations in relation to the provision of escape routes from offices. Section 5 contains recommendations on means of escape for ancillary accommodation.

Where offices form part of a shopping complex, additional recommendations for this situation are contained in BS 5588: Part 10: 1991. Fire precautions in the design, construction and use of buildings, Part 10. Code of practice for shopping complexes.

Purpose Group 4(a) and 4(b)

Shops and Shopping Centres

1.1.5 Guidance on the provision of means of escape in shops and shopping centres is provided in the following:

• BS 5588: Part 11: 1997, Fire precautions in the design, construction and use of buildings, Part 11. Code of practice for
  shops, offices, industrial, storage and other similar buildings; and

• Section 1.4 (General Provisions for means of escape) of this Technical Guidance Document; and where appropriate

• BS 5588: Part 10: 1991 Fire precautions in the design, construction and use of buildings, Part 10, Code of practice for shopping complexes.

Section 3 of BS 5588: Part 11: 1997 contains recommendations in relation to the provision of escape routes from shops. Section 5 contains recommendations on means of escape for ancillary accommodation.

Section 4 of BS 5588: Part 10: 1991 contains recommendations in relation to means of escape in shopping complexes. BS 5588: Part 10 also contains relevant supplementary guidance on means of escape for other uses, where these form part of a shopping centre.

Although the guidance in BS 5588: Part 11: 1997 is also relevant to individual shops which are part of a shopping centre, additional recommendations for these situations are contained in BS 5588: Part 10. The recommendations in Chapter 10 of BS 5588: Part 11 in relation to small premises do not apply when they are part of a shopping complex.

Note
Cafes, restaurants, public houses and other places of refreshments are regarded as Places of Assembly (Purpose Group 5) for the purpose of the Building Regulations and this Technical Guidance Document.

Purpose Group 5

Assembly and Recreation

1.1.6 Assembly and Recreation use includes a wide range of building types. Accordingly the relevant guidance will vary according to the sub-division, by building type, outlined below:

(i) Assembly and recreation buildings other than those used as a public house, restaurant, or similar premises, sports pavilion, stadium, grandstand or other spectator accommodation or school:

Appropriate guidance is contained in the following:

• BS 5588: Part 6: 1991, Fire precautions in the design, construction and use of buildings, Part 6, Code of practice for
  places of assembly; and

• Sub-section 1.4 (general provisions for means of escape) of this Technical Guidance Document.

(ii) Sports pavilion, stadium, grandstand or other spectator accommodation:

Appropriate guidance is contained in the following:

• Code of Practice for Safety at Sports Grounds, published by the Department of Education.

In this type of building, where assembly and recreation areas, other than spectator accommodation, are also provided (such as a bar or restaurant), the relevant guidance outlined at (iv) below should be used.

(iii) Guidance on the provision of means of escape in schools is provided in the following:

• Department of Education and Science (UK) Building Bulletin 7, Fire and the design of educational buildings; and

• Sub-section 1.4 (general provisions for means of escape) of this Technical Guidance Document.

Recommendations in relation to means of escape are contained in paragraphs 34 to 91 inclusive of Building Bulletin 7.

Buildings or parts of buildings which form part of a school or other educational facility may be used for purposes which are outside the scope of Building Bulletin 7. Where these occur, they should comply with the relevant code of practice or other document outlined in this sub-section (1.1).

(iv) Buildings used as a public house, restaurant or similar premises and buildings other than indicated in (i), (ii) and (iii) above.

Appropriate guidance is contained in subsections 1.2 to 1.4 of this Technical Guidance Document.

Where another use forms part (other than where ancillary) of an assembly and recreation building, the appropriate guidance in this section should be used. Where a place of assembly forms part of a shopping centre, additional recommendations for these situations are contained in BS 5588: Part 10 Fire precautions
in the design, construction and use of buildings, Code of practice for shopping complexes.

Other Purpose Groups

Other Building Types

1.1.7 Guidance on means of escape for buildings other than those indicated in 1.1.1 to 1.1.6 above is provided in the following sections of this Technical Guidance Document:

• Sub-section 1.2: Design for horizontal escape;
• Sub-section 1.3: Design for vertical escape; and
• Sub-section 1.4: General provisions for means of escape.

1.2 Design for Horizontal Escape

Introduction

1.2.1 The general principle to be followed when designing facilities for means of escape is that any person confronted by an outbreak of fire within a building can turn away from it and make a safe escape. This sub-section deals with the provision of means of escape from any point to the storey exit of the floor in question, for all types of building other than those covered by codes of practice or other documents which are referred to in sub-section 1.1.

This sub-section should be read in conjunction with the general provisions for means of escape in sub-section 1.4.

Number of Escape Routes and Exits

1.2.2 The number of escape routes and exits to be provided from a room or storey depends on the following factors:

• the number of occupants (see 1.2.2.1);

• the limitations on travel distance (see 1.2.2.2 and Table 1.2); and

• the minimum number of escape routes required (see 1.2.2.4 and Table 1.3);

1.2.2.1 Number of occupants The figure used for the number of occupants will normally be the design figure. When the number of occupants likely to use a room or storey is not known, the appropriate capacity should be calculated on the basis of the occupant capacity. Guidance is set out in paragraph 1.0.10 of this Document and Table 1.1. There may be cases where it may be reasonable to depart from the stated occupancy load factors.

The number of occupants in a room or storey will determine the width of escape routes and exits to be provided (see 1.2.4).

1.2.2.2 Travel distance The travel distance (see 1.0.9 for definition) from any point in a room or storey should not exceed the appropriate values indicated in Table 1.2 (illustrated in Diagram 1). The permitted travel distance will depend on whether escape is available in one direction only or in more than one direction. Escape is available in more than one direction where alternative escape routes exist (see 1.2.2.3).

Note: Travel distance limitations for Purpose Groups other than those indicated in Table 1.2 are contained in the appropriate code of practice or other document referred to in sub-section 1.1.

1.2.2.3 Alternative escape routes A choice of escape routes is of little value if they are all likely to be disabled simultaneously. Every escape route from a storey should be independent of any other escape route to which access may be obtained directly from that storey.

Alternative escape routes should satisfy the following criteria:

a. they are in directions 45° or more apart (Diagram 2 (a)); or

b. they are in directions less than 45° apart, but are separated from each other by fire-resisting construction (Diagram 2 (b)); or

c. (from any point from which there is initially a single direction of escape) they are in directions apart equal to 45° plus 2.5° for every metre travelled in one direction (Diagram 2 (c)).

Diagram 1 Travel distances

Table 1.2 Limitations on Travel Distance

Diagram 2 Alternative escape routes

1.2.2.4 Minimum number of escape routes The number of escape routes from any room or storey should be not less than that indicated in Table 1.3, except where permitted by par. 1.2.2.5 to be served by a single escape route.

Table 1.3 Minimum number of escape routes

1.2.2.5 Single escape route In order to avoid occupants being trapped by fire or smoke, there should be alternative escape routes from all parts of the building except for the situations listed below where a single route can be acceptable:

a. areas, except in a building of purpose group 2(a),Residential (Institutional), not likely to contain more than 50 persons, near enough to an exit to satisfy the limits on travel in one direction indicated in Table 1.2;

b. rooms which are not likely to contain more than 50 people, or 20 people if the building is in Residential (Institutional) use, provided that the limits on travel in one direction only are satisfied (see Table 1.2); or

c. a storey, except in the case of a building of purpose group 2(a), Residential (Institutional), which is not likely to contain more than 50 people, where the limits on travel in one direction only are satisfied (see Table 1.2).

In many cases the beginning of the escape route will be in one direction only (i.e. a single escape route) to a point where there are alternative escape routes. This is acceptable provided that the total travel distance to the nearest exit is within the limits for routes where escape is possible in more than one direction and the section with the single escape route does not exceed the limit for escape in one direction only (see Table 1.2 and Diagram 2(c)).

Planning of Escape Routes and Exits

1.2.3 The basic principle of escape route planning is that unless a route is very short, there should be an alternative which will not be affected if fire or smoke makes the first route impassable.

Every escape route should lead to a place of safety, and should give direct access to that place of safety, or give access thereto only by means of a circulation area.

1.2.3.1 Inner rooms A room whose only escape route is through another room is at risk if a fire starts in that other room. It is termed an inner room and is at risk from a fire in the outer room (access room).

Such an arrangement is only acceptable if the following conditions are satisfied:

a. the inner room should not be likely to have more than 20 occupants;

b. the inner room should not be a bedroom;

c. the escape route from the inner room should not pass through more than one outer (access) room;

d the travel distance from any point in the inner room to the exit(s) from the access room should not exceed the appropriate limit given in Table 1.2;

e. the access room should not be a place of special fire risk and it should be in the control of the same occupier; and

f. one of the following arrangements are made -

• the enclosures (walls or partitions) of the inner room are stopped at least 500 mm below the ceiling, or

• a vision panel is located in the enclosure of the inner room, of sufficient size, to enable occupants of the inner room to see if a fire has started in the outer room, or

• the access room is fitted with a suitable fire detection and alarm system to warn the occupants of the inner room should an outbreak of fire occur in the access room.

1.2.3.2 Open connections between floors Routes and exits should not be prejudiced by open connections between floors. Where travel is in one direction only, it should not be within 5 m of an open connection between floors unless it is leading away from the opening. Where there is a choice of routes, at least one of them should lead away from the opening (see Diagram 3).

Diagram 3 Exit routes in relation to openings between floors

1.2.3.3 Planning of exits in a central core Buildings with more than one exit in a central core should be planned so that storey exits are remote from one another, and so that no two exits are approached from the same lift hall, common lobby r undivided corridor, or linked by any of these (see Diagram 4).

1.2.3.4 Access to storey exits A storey which should have more than one escape stairway should be planned so that it is not necessary to pass through one stairway to reach another.

1.2.3.5 Separation of circulation routes from stairways An escape stairway should not form part of the primary circulation route between different parts of the building at the same level. An exception to this requirement may be made in the case of a building, having not more than three storeys (see Appendix C , Diagram 36), which is served by a single escape stairway (see 1.3.3) where rooms open directly into the enclosure to the stairway and where self-closing fire doors are unlikely to be rendered ineffective as a result of constant use.

Diagram 4 Central core arrangement

1.2.3.6 Storeys divided into different occupancies Where any storey is divided into separate occupancies (i.e. where there are separate ownerships or tenancies of different organisations):

a. the means of escape from each occupancy should in general not pass through any other occupancy;

b. the common corridor serving different occupancies should be a protected corridor (see 1.2.5.1); and

c. a fire detection and alarm system, complying with the requirements for at least an L3 type system as defined in I.S. 3218: 1989, should be provided throughout the storey (see 1.4.14).

Width of Escape Routes and Exits

1.2.4 T he width of escape routes and exits depends on the number of persons needing to use them, and should not be less than the dimensions given in Table 1.4.

Table 1.4 Width of escape routes and exits

There is a possibility that one escape route may become unavailable due to a fire in a building. Except where permitted to be served by a single escape route (see 1.2.2.5), or where all the exits from an area open directly to the open air at ground floor level, it will be necessary to take account of this when calculating the total capacity of available escape routes. It is therefore necessary to consider the effect of discounting each escape route in turn.

The total capacity of the escape routes and exits from any room or storey should be adequate for the number of occupants, taking account of discounting, where required. The total capacity should be based on the sum of the capacities of each individual escape route or exit, based on the values indicated in Table 1.4, with an allowance for discounting where applicable.

In assembly and recreation buildings (purpose Group 5), the escape route provided by the main entrance to the building should be capable of discharging at least one third of the occupant capacity in accordance with the provisions of Table 1.4.

In Residential (Institutional) buildings (Purpose Group 2(a)) an escape route should generally be not less than 1150 mm in width and where appropriate, be suitably designed to allow the movement of beds along the escape route. The width of an exit from any room should be adequate for the appropriate evacuation procedures, taking into account the physical capacity and dependency of the occupants and should not be less than 900 mm.

Special provisions, which include the width of seatways and gangways, apply to areas with closely seated audiences (see 1.2.8).

1.2.5 Corridors

1.2.5.1 Protected corridors- A corridor which serves as part of the means of escape in any of the following circumstances should be a protected corridor (see Table A1, Appendix A):

a. every corridor serving sleeping accommodation within Residential (Institutional) or other Residential buildings (Purpose Groups 2(a) or 2(b));

b. every dead-end corridor;

c. any corridor common to two or more different occupancies (see also par. 1.2.3.6).

1.2.5.2 Enclosure of corridors that are not protected corridors T he enclosures to all corridors used as means of escape (which are not protected corridors) should be carried up to the underside of the structural floor above (or to a suspended ceiling) and all openings in the corridor enclosures should be fitted with doors.

1.2.5.3 Sub-division of corridors If a corridor provides access to alternative escape routes, there is a risk that smoke will spread along it and make both routes impassable before all occupants have escaped. To avoid this, every corridor connecting two or more storey exits where the distance between storey exits exceeds 12 m should be sub-divided by self-closing fire doors (and any necessary associated screens) so that:

a. no length of undivided corridor is common to two storey exits; and

b. the fire door(s) are positioned to effectively safeguard the route from smoke, having regard to the layout of the corridor and to any adjacent fire risks.

1.2.5.4 Separation of dead-ends If a dead-end portion of a corridor provides access to a point from which alternative escape routes are available, there is a risk that smoke from a fire could make both routes impassable before the occupants in the dead-end have escaped. To avoid this, unless the escape stairway(s) and corridors are protected by a pressurization system complying with BS 5588: Part 4: 1978; every dead end corridor exceeding 4.5 m in length should be separated by self-closing fire doors (together with any necessary associated screens) from any part of the corridor which:

a. provides two directions of escape (Diagram 5(a)); or

b. continues past one storey exit to another(Diagram 5(b)).

1.2.6 External Escape Routes

1.2.6.1 External escape stairway If more than one escape route is required from a storey, or part of a building, one of those routes may be by way of an external escape stairway provided that:

a. in the case of an assembly and recreation building, the route is not intended for use by members of the public; or

b. in the case of a Residential (Institutional) building, the route serves only office or residential staff accommodation.

In the case of an existing building, the use of an external escape stairway as an alternative means of escape may be acceptable, where there is no practicable alternative solution. Where the building is used for assembly and recreation, the number of persons likely to use the stairway should not exceed 150.

External escape stairways should comply with the requirements set out in par. 1.3.9.

1.2.6.2 Escape over flat roofs If more than one escape route is required from a storey, or part of a building, one of those routes may be by way of a flat roof, provided that:

a. the route does not serve a Residential (Institutional) building, or a part of a building intended for use by members of the public;

b. the roof is part of the same building from which escape is being made, or if it is part of another building, there is a legal agreement between the parties concerned which includes a right of entry into that building;

c. the route across the roof leads to a storey exit;

d. the part of the roof forming the escape route and its supporting structure, together with any opening within 3 m of the escape route, is fire resisting; and
the route is adequately defined and guarded by walls and/or protective barriers which meet the provisions in Technical Guidance Document K.

In the case of any existing building, an escape route by way of a flat roof which complies with (b) to (e) above may be acceptable as an alternative means of escape, where combined with an external escape stairway as outlined at 1.2.6.1 above. Where the building is used for assembly and recreation the numbers of persons likely to use such an escape route should not exceed 150.

The provisions of this paragraph do not prohibit an escape route by way of an external podium which gives direct access to a place of safety and where the roof is constructed of non-combustible construction having a fire resistance of at least 60 minutes.

Diagram 5 Dead end corridors

1.2.7 Evacuation Considerations

1.2.7.1 General In premises of Purpose Group 2(a), Residential (Institutional), occupants may be totally dependant on other people for evacuation. Normal "self-help" evacuation procedures are therefore inappropriate and consideration must be given to designing escape routes to facilitate the planned mode of evacuation. T he following provisions should be made to allow progressive horizontal escape to be made into adjoining compartments in those parts of buildings used to accommodate occupants of this type. The object is to provide a place of relative safety within a short distance, from which further evacuation can be made if necessary but under less pressure of time.

1.2.7.2 Compartmentation Every storey used for occupants of the type described in 1.2.7.1 above should be divided into at least two compartments in such a way as to permit horizontal evacuation of each compartment.

1.2.7.3 Planning for progressive horizontal evacuation In planning a storey which is divided into compartments for progressive horizontal evacuation, the following conditions should be observed:

a. Adjoining compartments into which horizontal evacuation may take place should each have a floor area sufficient to accommodate not only their own occupants but the occupants from the adjoining compartment. This should be calculated on the basis of the design occupancy of the compartments.

b. Each compartment should have at least one other escape route, independent of the route into the adjoining compartment (see Diagram 6). T his other route may be by way of a third compartment, provided that compartment contains a storey exit which is not by way of another compartment, and which is independent from the exits from the other compartments.

Where the above conditions have been met, for the purpose of travel distance (see 1.2.2.2), a door in a compartment wall may be regarded as being equivalent to a storey exit.

Diagram 6 Progressive horizontal evacuation

1.2.8 Closely-Seated Audiences

There are particular problems that arise when people are limited in their ability to escape by fixed seating. Any such arrangements made for a closely seated audience (or seated spectators) should meet the provisions set out in Section 3, Sub-Section 8, to BS 5588: Part 6: 1991.

1.2.9 Premises provided with a Stage

Stage areas present particular problems in that they present additional fire risk from the presence of combustible materials. W here stage areas occur they should comply with the provisions for these areas set out in Section 5, Sub-Section 13, to BS 5588: Part 6: 1991.

1.3 Design for Vertical Escape

1.3.1 Introduction

An important aspect of means of escape in multi storey buildings is the availability of a sufficient number of adequately-sized and protected escape stairways. This Section deals with these matters, including measures necessary to protect escape stairways, for all types of building other than those covered by codes of practice or other documents which are referred to in sub-section 1.1.

It should be read in conjunction with the general provisions for means of escape in sub-section 1.4.

1.3.2 Number of Escape Stairways

1.3.2.1 The number of escape stairways needed in a building (or part of a building) will be determined by:

a. the constraints imposed in sub-section 1.2 on the design of horizontal escape routes;

b. whether independent stairways are required in mixed occupancy buildings (see 1.3.2.3 below);

c. whether a single stairway is acceptable (see par.1.3.3); and

d. provision of adequate width for escape (see paragraph 1.3.4).

1.3.2.2 In larger buildings, provisions for access for the fire service may apply. Some escape stairways may need to serve also as fire-fighting stairways. The number of escape stairways may therefore be affected by the requirements of B5 (see 5.3).

1.3.2.3 Where a building contains storeys, or parts of storeys, in different purpose groups and if one of those purpose groups is either assembly and recreation or residential it should have means of escape which are independent of any other purpose group except for the conditions described below.

In a building with not more than four storeys above ground or access level, a stairway may serve both dwellings and non-residential occupancies where:

• the stairway is separated from each occupancy by protected lobbies (see 1.3.8) at all levels; and

• an automatic fire detection and alarm system is provided throughout the building (see 1.4.14).

In a building with more than four storeys above ground or access level, a stairway serving a flat or maisonette should not communicate with other nonresidential occupancies unless:

• the flat or maisonette is ancillary to the main use of the building;

• the stairway is separated from each occupancy by protected lobbies (see 1.3.8) at all levels;

• an independent alternative escape route is provided from the flat or maisonette; and

• an automatic fire detection and alarm system is provided throughout the building (see 1.4.14).

1.3.3 Single Escape Stairways

The situations where a building (or part of a building) other than buildings of Purpose Group 2(a) Residential (Institutional), may be served by a single escape stairway are:

a. if there is no storey with a floor level in the case of a Purpose Group 5 building more than 5 m above ground level, or in other cases more than 10 m above ground level, and where (in accordance with par. 1.2.2.5) every storey may have a single escape route, or

b. if there is a basement the floor of which is not more than 3 m below ground level where (in accordance with par. 1.2.2.5) every basement storey may have a single escape route.

1.3.4 Width of Escape Stairways

The width of escape stairways should:

a. be not less than the width(s) required for any exit(s) affording access to them;

b. conform with the minimum widths given in Table 1.5;

c. more than 30 m above ground level; and

d. not narrow at any point on their way to a final exit.

If the width of the stairway is more than 1800 mm, then for reasons of safety in use the stairway should have a central handrail. In such a case the stairway width on each side of the handrail needs to be considered separately for the purpose of assessing stairway capacity.

Where an exit route from a stairway also forms the escape route from the ground and/or basement storeys, the width may need to be increased accordingly.

In buildings of Purpose Group 2(a) Residential (Institutional), any landing associated with a stairway forming part of an escape route should be adequate for the purposes of evacuation. Where evacuation of beds or mattresses by way of a stairway is likely to be required, any landing associated with such a stairway should have a width not less than 2800 mm and a depth clear of obstructions not less than 1950 mm.

1.3.5 Calculation of Minimum Stairway Width

1.3.5.1 General Every escape stairway should be wide enough to accommodate the number of persons needing to use it in an emergency. This will depend on the number of stairways provided and whether the escape strategy is based on the total or phased evacuation of the building (or part of the building).

Escape based on total evacuation should be used for:

a. all stairs serving basements;

b. all stairs serving buildings with open spatial planning; and

c. all stairs serving Residential or Assembly and recreation buildings.

Paragraph 1.3.5.3 deals with the concept of total evacuation. Table 1.6 assumes the total evacuation of all storeys simultaneously.

Paragraph 1.3.5.4 deals with the concept of phased evacuation, and sets out the special measures that are necessary if a system of phased evacuation is used. Table 1.7 assumes the phased evacuation of not more than two floors at a time, and should be used for buildings over 30 m high, provided that the building is not one that is identified in the previous paragraph as needing to be designed on the basis of total evacuation.

Table 1.5 Minimum width of escape stairways

Buildings, other than those identified above as needing to be designed on the basis of total evacuation which are less than 30 m high may also be designed on the basis of phased evacuation if the provisions in par. 1.3.5.4 are met.

1.3.5.2 Discounting of stairways Whichever method of evacuation is used, where two or more stairways are provided it should be assumed that one of them might not be available due to fire or smoke. It is therefore necessary to discount each stairway in turn in order to ensure that the capacity of the remaining stairways is adequate for the number of persons needing to escape.

An exception to the provision to discount stairways in turn is if every escape stairway is approached on each storey through a protected lobby. In such a case the likelihood of a stairway not being available is significantly reduced and it is not necessary to discount a stairway. A protected lobby need not be provided on the topmost storey for the exception to apply. Another exception is if the stairways are protected by a suitable pressurisation system. A design method for pressurisation of escape routes is set out in BS EN 12101-6. The discounting of one stairway applies to a building fitted with a sprinkler system, unless the stairways are lobbied or provided with a pressurisation system as described above.

The exceptions listed above to the requirement for discounting each stairway in turn should not be applied to :

• assembly and recreation (Purpose Group 5) buildings;

• any building where, by virtue of the limits on travel distance and/or numbers of occupants, less than three stairways are required;

• any building with a storey more than 20 m above ground level.

As with the design of horizontal escape routes, where the maximum number of people needing to use the escape stairway is not known, the appropriate capacity should be calculated on the basis of the occupant capacity. Guidance is set out in paragraph 1.0.10 and Table 1.1 of this Technical Guidance Document.

1.3.5.3 Total evacuation In a building designed for total evacuation, the escape stairways should have the capacity to allow all floors to be evacuated simultaneously. Persons on the lower floors will evacuate from the building quicker than those on the upper floors and account is also taken of persons within the stairways during the evacuation process.

Table 1.6 gives capacities, based on total evacuation, for stairways of different widths (1000 mm to 1800 mm) and numbers of storeys served (1 to 10).

Table 1.6 has been derived from the formula:

P = 200w + 50(w - 0.3)(n - 1), where:

P: is the number of people that can be accommodated;
w: is the width of the stairway in metres; and
n: is the number of storeys served.

The formula above may be used as an alternative to Table 1.6 or for more than 10 storeys.

The widths of stairways provided should also meet the criteria indicated at 1.3.4 and take account of the need, where required, to discount any one stairway (see 1.3.5.2).

Table 1.6 Capacities of stairways (Total Evacuation)

1.3.5.4 Phased evacuation The concept of phased evacuation is based on evacuating persons on a sequential basis, commencing with those on the storeys most affected by the fire in its initial stages. That is the storey of fire origin and the one immediately above. By designing on the basis of phased evacuation, stairway widths less than those needed for total evacuation are possible. However, a package of compensatory features are needed. These are set out below:

a. the stairways should be approached through a protected lobby or protected corridor at each storey except a top storey consisting exclusively of plant rooms;

b. every floor should be a compartment floor;

c. if the building has a storey with a floor over 30 m above ground level, the building should be protected throughout by an automatic sprinkler system meeting the relevant recommendations of BS 5306 Fire extinguishing installations and equipment on premises: Part 2: Specification for sprinkler systems, i.e. the relevant occupancy rating together with the additional requirements for life safety.

d. the building should be fitted with an appropriate fire detection and alarm system (see 1.4.14);

e. an internal speech communication system, such as a telephone or intercom system, should be provided to permit conversation between a control point at fire service access level, and a fire warden on every storey.

The minimum width of stairway designed on the basis of phased evacuation is indicated in Table 1.7. This table assumes a phased evacuation of not more than two floors at a time.

The success of a system of phased evacuation depends to a large extent on the satisfactory functioning of the measures outlined above. Arrangements for the proper maintenance of the systems are necessary, as are arrangements for proper management and training. These matters are not appropriate for control under Building Regulations, but satisfactory arrangements may be sought under other legislation relevant to the occupancy.

Table 1.7 Minimum aggregate width of stairways for phased evacuation

1.3.6 Protection of Escape Stairways

1.3.6.1 General Escape stairways need to have a satisfactory standard of fire protection if they are to fulfil their role as areas of relative safety during a fire evacuation. Protection of escape stairways is provided by enclosure of the stairway by fire resisting construction. Certain situations (see 1.3.8) require the additional protection provided by a protected access lobby or corridor to the stairway.

In certain situations such as from a gallery, an open stairway may form part of an escape route conforming with the constraints of sub-section 1.2, but such a stairway may not be regarded as an escape stairway of the type described above.

Escape stairways should conform with the provisions in pars. 1.3.6.2 to 1.3.6.6 below.

1.3.6.2 Enclosure of escape stairways Every escape stairway, unless it is an external escape stairway (see 1.3.9), should be situated within a fire resisting enclosure (i.e. it should be a protected stairway).

There may be additional provisions if the stairway is also a protected shaft (where it penetrates one or more compartment floors, see Section B3) or if it is a fire-fighting stairway (see Section B5).

The performance requirements for the enclosure to a protected stairway are indicated in Appendix A (Tables A1 and A2). The performance requirements for doors to the enclosure are contained in Appendix B (Table B1).

1.3.6.3 Exits from protected stairways Every protected stairway should discharge:

a. directly to a final exit; or

b. by way of a protected exit passageway to a final exit.

1.3.6.4 Separation of adjoining stairways Where two protected stairways (or exit passageways leading to different final exits) are adjacent, they should be separated by an imperforate enclosure.

1.3.6.5 Use of space within protected stairways A protected stairway needs to be relatively free of potential sources of fire. Consequently, items that may be incorporated in a protected stairway are limited to the following:

a. sanitary accommodation or washrooms are permitted, provided that the accommodation is not used as a cloakroom. A gas water heater or sanitary incinerator may be installed in the accommodation, but the accommodation should not include any other gas appliance.

b. a lift may be included in a protected stairway.There are other provisions about lifts in Section 1.4.9.

c. if the protected stairway serves part of a building that has access to at least one other escape stairway, then a reception or enquiry area may be included in the stairway at ground or access level. The reception or enquiry area should not be more than 10 m2 in area. Cupboards enclosed with fire-resisting construction may also be included in such a protected stairway.

1.3.6.6 Fire resistance and openings in external walls of protected stairways With some configurations of external wall, a fire in one part of a building could subject the external wall, of a protected stairway to heat (for example, where the two are adjacent at an internal angle in the facade as shown in Diagram 7). If the external wall of the protected stairway has little fire resistance, there is a risk that this could prevent the safe use of the stairway.

Where a protected stairway projects beyond, or is recessed from, or is in an internal angle of, the adjoining external wall of the building, then the distance between any unprotected area in the external enclosures to the building and any unprotected area in the enclosure to the stairway should be at least 1.8 m (see Diagram 7).

1.3.6.7 Gas service pipes in protected stairways Pipes intended to carry gaseous or liquid fuels and associated equipment should not be incorporated within a protected stairway.

1.3.6.8 Separation of special fire risk areas Escape stairways require a high degree of protection from fire. Rooms or other accommodation which have doors opening onto escape stairways can threaten the escape routes from a building. Places of special fire risk (see 1.0.9) should therefore be located so that they do not communicate directly with the enclosure to a protected stairway.

1.3.7 Basement Stairways

Because of their situation, basement stairways are more likely to be filled with smoke and heat than are stairways in ground and upper storeys. Special measures are therefore needed in order to prevent a basement fire causing a hazard to upper storeys. These are set out in the paragraphs below.

Diagram 7 External protection to protected stairway

1.3.7.1 If an escape stairway forms part of the only escape route from an upper storey of a building (or part of a building) it should not be continued down to serve any basement storey. Any escape stairway between a basement and the ground storey should be separated by a protected lobby or protected corridor from the stairway serving the upper storeys.

1.3.7.2 If there is more than one escape stairway from an upper storey of a building (or part of a building), only one of the stairways serving the upper storeys of the building (or part) need be terminated at ground level. Other stairways may connect with the basement storey(s) if they are separated at each basement level by a protected lobby or protected corridor.

1.3.8 Protected Lobbies and Corridors to Escape Stairways

1.3.8.1 Provision of protected lobbies and corridors- In addition to stairways serving basements (see 1.3.7), there are other situations where an escape stairway requires the added protection of a protected lobby or corridor. These are:

a. where the stairway is the only stairway serving a building (or part of a building) which has three or more storeys (see Appendix C , Diagram 36), except in the case in a small guesthouse (see 1.3.8.2);

b. where the stairway serves any storey at a height greater than 20 m (see Appendix C , Diagram 38);

c. where the building is designed for phased evacuation (see 1.3.5.4);

d. between a protected stairway and a place of special fire risk (see 1.0.9);

e. in a sprinklered building in which the stairway width has not been based on discounting one stairway (see 1.3.5.2); or

f. in a building serving flats and maisonettes and other non-residential occupancy (see 1.3.2.3).

in the above mentioned situations, access to the protected stairway should be by way of protected lobbies or protected corridors at all storey levels, except at the top-most level.

1.3.8.2 Small guesthouses (Purpose Group 2(b)) An exception to the requirement for a protected lobby or corridor to the stairway in a building served by a single escape stairway may be made in the case of a guesthouse (Purpose Group 2(b)), where the following conditions are met:

• the house does not contain a basement and there are not more than three storeys (see Diagram 36);

• there are not more than four bedrooms on any upper storey;

• the stairway is a protected stairway (see 1.3.6.2);

• a fire detection and alarm system is provided in accordance with the requirements of par. 1.4.14; and

• all habitable rooms are provided with windows which can be used for escape or rescue (see 1.5.6).

1.3.8.3 Existing buildings In the case of some existing buildings, the provision of protected lobbies or corridors to an existing escape stairway may not be practicable. In these situations, it would be appropriate to consider alternative solutions and the provision of compensating features (see 1.0.11.2 and 1.0.11.3). The nature and extent of the additional measures required will depend on the circumstances of each particular case.

Where protected lobbies or corridors can not be provided, it will be necessary to consider the following items in the context of the need to ensure a satisfactory level of protection to the means of escape:

• the nature and extent of the occupancies and accommodation adjoining the protected stairway;

• the fire performance of the stairway enclosure;

• the performance of fire door assemblies as installed in the building (see Appendix B);

• smoke control measures to protect the stairway enclosure; and

• life safety protection to be provided by the fire detection and alarm system (see 1.4.14).

1.3.8.4 Requirements for protected lobbies and corridors Every protected lobby or corridor which is required to be provided should comply with the following:

• be constructed with walls having fire resistance as required in Section B3 for the protecting structure of the stairway, as per Table A1 Item 11 and any door to the lobby should be a self closing fire door having a fire resistance not less than half that required for the wall, but not less than 30 minutes;

• be constructed so that the clearance between the edges of the doors when fully open is not less than 500 mm, and the distance between the doors in the closed position is not less than 1 m, or when the distance between any two doors in the closed position is less than 1 m, the planes of such doors are at an angle to one another of not less than 90 degrees; and

• in the case of a protected lobby or corridor at basement level, be ventilated by means of permanent openings to the open air having an area not less than 0.05 m2, or where the protected lobby or corridor provides access at any storey level to an enclosed car park or area of special fire risk, be ventilated by means of permanent openings to the open air having an area not less than 0.4 m2. Where the lobby or corridor is not adjacent to an external wall of the building, any connecting ventilation ductwork should be protected by fire-resisting construction.

1.3.9 External Escape Stairways

In limited situations (see 1.2.6) external stairways are acceptable as forming part of an escape route. It is important that the external stairway is sufficiently protected from the weather and is adequately protected from a fire in the building. The following conditions should be met:

a. unless the stairway is of limited height, it should be protected from the effects of snow and ice. The degree of protection required will depend on the location of the stairway and the protection that might be afforded to the stairway by the building itself. Weather protection is not required if the stairway serves a floor or storey which is not more than 6 m above the external ground level.

b. all doors affording access to the stairway should be fire-resisting, except that a fire-resisting door is not required at the head of any stairway leading downwards and where there is only one exit from the building onto the top landing;

c. any part of the external walls identified below should be of fire-resisting construction:

• within 1.8 m of, and 9 m vertically below, the flights and landings of a stairway leading downwards; and

• within 1.8 m of, and vertically above, the flights and landings of a stairway leading upwards; and

• within 3 m of the escape route from the foot of the stairway at ground level to a place of safety.

Note: Unprotected openings are not permitted in those parts identified above. Any doors should be fire-resisting and windows should be fire-resisting and fixed shut.

The construction of external escape stairways should comply with the requirements outlined in 1.4.4.

Diagram 8 shows two examples of unprotected external escape stairways.

Diagram 8 External escape stairways

1.4 General Provisions for Means of Escape

Introduction

1.4.1 This sub-section deals with a number of provisions about the construction and protection of escape routes generally, and about some services installations and other matters associated with the design of escape routes. It applies to all buildings other than Purpose Groups 1(a) and 1(b) - dwelling houses.

It should therefore be read in conjunction with sub-sections 1.1, 1.2 and 1.3 of this Document.

1.4.2 Protection of Escape Routes

1.4.2.1 Fire resistance of enclosures. Details of fire resistance test criteria, and standards of performance, are set out in Appendix A to this Document.
All walls, partitions and other enclosures that need to be fire-resisting to meet the provisions in this Document should have the appropriate performance given in Tables A1 and A2 of Appendix A. They should also meet any limitations on the use of glass (see par. 1.4.2.3).

1.4.2.2 Fire resistance of doors. Details of fire resistance test criteria, and standards of performance for fire doors, are set out in Appendix B to this Document.

Note: Any reference to a fire door in this Technical Guidance Document, or in any code of practice or other document referred to in this Technical Guidance Document, is intended to mean a complete door assembly which includes the door leaf or leaves, the door frame, ironmongery (hinges, latches, closers, etc.) and any seals where required between the frame and leaf or between leaves, and which is installed in a building and is capable of meeting the required performance. The performance of a fire door will critically depend on the correct installation of the complete door assembly.

All doors that need to be fire-resisting to meet the provisions in this Document should have the appropriate performance given in T able B1 of Appendix B. They should also meet any limitations on the use of glass (see par. 1.4.2.3).

1.4.2.3 Fire resistance of glazed elements Where glazed elements in fire-resisting enclosures and doors are only able to satisfy the relevant performance in terms of integrity, the use of glass is limited. These limitations are set out in Appendix A, Table A4.

Where the relevant performance can be met in terms of both integrity and insulation, there is no restriction in this Section on the use or amount of glass, but there may be some restriction under Section B5.

1.4.2.4 Protection of escape stairways The protection of escape stairways should be in accordance with the provisions outlined at 1.3.6, unless the stairway is an unprotected stairway forming part of an escape route in accordance with the provisions of any C ode of Practice or other Document referred to in sub-section 1.1 appropriate to the particular use.

1.4.3 Doors on Escape Routes

1.4.3.1 The time taken to negotiate a closed door can be critical in an escape situation. Doors on escape routes (both within and from the building) should therefore be readily openable if undue delay is to be avoided. Accordingly the provisions in the paragraphs below should be met.

1.4.3.2 Door fastenings In general, doors on escape routes, whether or not the doors are fire doors, should either not be fitted with lock, latch or bolt fastenings, or they should only be fitted with simple fastenings that can be readily operated in the direction of escape without the use of a key.

Where security on final exit doors is an important consideration, such as some assembly or commercial uses, panic bolts should be used to secure doors. W here additional security is required when the premises is not in use, hardware which is fully removable should be used. T he following recommendations apply to buildings, or parts of buildings which are used for assembly or recreation (Purpose Group 5):

a. Exit doors from areas holding more than 50 people should either be free from fastenings or be fitted with panic bolts complying with I.S. EN 1125 1997.

b. Doors, other than those covered by item (a),should be fitted only with simple fastenings that can be operated from the escape side of the door without the use of a key.

Attention is drawn to the provisions of the Fire Safety in Places of Assembly (Ease of Escape), Regulations, 1985 (S.I. No. 249 of 1985).

Information about door closing and hold open devices for fire doors is given in Appendix B.

1.4.3.3 Direction of opening Doors on escape routes should be hung so that they open in the direction of escape. In the case of small rooms or buildings, this may not be practical or indeed necessary, but in the following situations doors on escape routes must always be hung to open in the direction of escape:

a. from a place of special fire risk, or

b. in the case of premises comprising an industrial, storage or assembly and recreation use if more than 20 people are expected to use them, or

c. in the case of any other premises if more than 50 people are expected to use them.

An exception to the requirement for outward opening doors on escape routes may be made in the case of class-rooms and other small rooms in schools where the number of persons in such rooms does not exceed 60.

Manual sliding doors may be permitted, in certain limited circumstances only, such as doors from rooms in industrial or storage buildings which are occupied by not more than 10 persons and where swing doors would be impracticable.

As an alternative to outward opening doors, in certain limited situations, it may be appropriate to consider the provision of doors which are held in the open position. It should not be possible for such doors to be released and closed when the building is in use.

1.4.3.4 Amount of opening and effect on associated escape routes All doors on escape routes should be hung to open not less than 90°, and with a swing that is clear of any change of floor level, other than a threshold on the line of the doorway, and does not reduce the required width of any escape route across a landing.

Similarly, where it is necessary to recess a door that is opening towards a corridor, then the depth of recess should be sufficient that the door swing does not reduce the required width of the corridor.

1.4.3.5 Vision panels These are needed where doors on escape routes subdivide corridors, or where the doors are hung to swing both ways.

1.4.3.6 Revolving and automatic doors
Revolving doors, automatic doors and turnstiles can obstruct the passage of persons escaping. These types of doors should not be provided across escape routes unless:

a. they are automatic doors complying with BS 7036: and either:

• they are arranged to fail safely to outward opening from any position of opening; or

• they are provided with a monitored fail safe system for opening the doors if the mains power supply fails; or

b. swing doors to the required width are provided immediately adjacent.

1.4.4 Construction of Escape Stairways

1.4.4.1 General Every escape stairway and its associated landings should be constructed of materials of limited combustibility in the following situations.

a. if it is the only stairway serving the building, or part of the building, and the period of fire resistance for the elements of structure (Tables A1, A2 to Appendix A) is 60 minutes or more,

b. if it is within a basement storey,

c. if it serves any storey having a floor level more than 18 m above ground or access level, or

d. if it is an external stairway (there are other provisions about external escape stairways in par. 1.3.9).

In satisfying the above provision, combustible materials may be added to the upper surface of these stairways, except in the case of firefighting stairs.

An exception to the requirement for escape stairways to be constructed of materials of limited combustibility may be made in the case of an existing internal stairway in any existing building where:

• the width of the stairway and dimensions of steps are adequate for the purposes of means of escape, and

• the stairway is of sound construction and is capable of affording safe passage for the users of the building.

There are other provisions dealing with the construction of fire fighting stairways in Section B5.

Escape stairways should comply with the requirements of Section 1 of Technical Guidance Document K - Stairways, Ladders, Ramps and Guards, to the Building Regulations, 1997. An exception to this requirement may be made in the case of an existing stairway in an existing building which is capable of affording safe passage for the users of the building.

1.4.4.2 Helical, spiral stairways and fixed ladders Helical and spiral stairways and fixed ladders may form part of an escape route subject to the following restrictions:

a. Helical and Spiral stairways should comply with the recommendations of BS 5395 Stairs, ladders and walkways: Part 2 C ode of Practice for the design of helical and spiral stairs. If they are intended to serve members of the public, they should meet the requirements for a type E (public) stairway to that standard.

b. In the case of fixed ladders, these should only be intended for use by able-bodied adults, and in circumstances where it is not practical to provide a more satisfactory means of vertical egress. Fixed ladders are acceptable within plant rooms.

In addition, fixed ladders should be constructed of non-combustible materials.

Guidance on the design of Helical and Spiral stairways and fixed ladders, from the aspect of safety in use, is given in Technical Guidance Document K.

1.4.5 Height of Escape Routes

All escape routes should have a minimum clear headroom of not less than 2 m and there should be no projection below this height, except for any door frame, which would impede the free flow of persons using them.

1.4.6 Floors of Escape Routes

The floors of all escape routes (including steps, ramps and landings) should have non-slippery even surfaces.

Where a ramp forms part of an escape route, it should not be steeper than 1 in 12 if it is shorter than 9 m, otherwise it should not be steeper than 1 in 20.

Any sloping floor or tier should be constructed with a pitch of not more than 35° to the horizontal.

Further guidance on the design of ramps and associated landings, from the aspect of safety in use, is given in Technical Guidance Documents K and M.

1.4.7 Final Exits

Final exits need to be dimensioned and sited so that they facilitate the evacuation of persons out of the building, and away from the building. Accordingly, they should be not less in width than the escape route(s) they serve and also meet the following provisions in the paragraphs below.

Final exits should be sited to ensure rapid dispersal of persons from the vicinity of the building so that they are no longer in danger from fire and smoke. Direct access to a street, passageway, walkway or open space should be available. The route clear of the building should be well defined, and suitably guarded if necessary, in situations where the exit discharges other than to an open street or open space at street level.

Final exits also need to be apparent to persons who may need to use them. This is particularly important where the exit opens off a stairway that continues down, or up, beyond the level of the final exit.

Final exits also need to be sited so that they are clear of any risk from fire or smoke in a basement, or from openings to transformer chambers, boiler rooms and similar risks.

1.4.8 Lighting of Escape Routes

1.4.8.1 The safe movement of persons along escape routes, towards and through the exits to a place of safety, depends on the illumination of those routes and the ability to see hazards and changes of level and direction. Adequate artificial lighting should be provided to all internal and external escape routes, except in the case where there is adequate natural lighting and the building is used only during daylight hours.

1.4.8.2 In the event of failure of the normal lighting, emergency escape lighting is required. Emergency escape lighting is required to ensure that lighting is provided promptly, automatically and for a suitable duration when the normal lighting fails. Emergency escape lighting is required on complete failure of the power supplies to the normal lighting in the building and also on a localised failure of the normal lighting.

1.4.8.3 Emergency escape lighting should be provided:

a. to indicate clearly and unambiguously the escape routes so that the means of escape can be safely and effectively used;

b. to provide illumination along such routes to allow safe movement towards and through the exits provided;

c. to ensure that fire alarm call points and first-aid fire fighting equipment, where provided, can be readily located.

Note: Emergency escape lighting may also be required for the purpose of the Safety, Health and Welfare at Work Act, 2005 to enable work activities to be safely terminated and allow other emergency actions to be effectively carried out. Additional emergency escape lighting may also be required under the Fire Services Act, 1981 when the building is in use. The provisions outlined in this Section may need to be supplemented accordingly.

1.4.8.4 Emergency escape lighting should be provided in accordance with the provisions indicated in T able 1.8. For the purpose of this table the emergency escape lighting may consist of the following parts:

a. un-defined escape routes: open areas in a building where the escape routes are not fixed or defined by the elements of construction;

b. defined escape routes: routes, such as exits, escape corridors and escape stairways, through which or along which, persons may be required to travel to reach a final exit from a building;

c. external escape routes: those parts of an escape route outside a building from a final exit, which may be required for persons to reach a place of safety.

1.4.8.5 Emergency escape lighting should be designed and installed in accordance with the relevant recommendations in I.S. 3217: 1989 C ode of practice for emergency lighting.

1.4.9 Lifts

1.4.9.1 Evacuation lifts In general it is not appropriate to use lifts when there is a fire in the building because there is always the danger of the lift becoming immobilised as a result of the fire, and of persons being trapped inside. However, in some circumstances a lift may be needed as part of a management plan for evacuating people with disabilities. In such cases the lift installation needs to be appropriately sited and protected, and needs to contain a number of safety features that are intended to ensure that the lift may remain usable for evacuation purposes during the fire.

Table 1.8 Provision of emergency escape lighting

1.4.9.2 Fire protection of lift installations generally Because lifts by their nature connect floors, there is the possibility that they may prejudice escape routes. T o safeguard against this, the following provisions in the paragraphs below should be met.

Lifts, which rise within a large volume such as a mall or atrium, and do not have a conventional lift-well, may be at risk if they run through a smoke reservoir. In these cases care is needed to maintain the integrity of any smoke reservoir, and protect the occupants of the lift.

Lift wells should be either contained within the enclosures of a protected stairway, or be enclosed throughout their height with fire-resisting construction if they are sited such as to prejudice the means of escape. A lift well connecting different compartments should form a protected shaft (see Section B3, 3.2).

Lifts should be approached only by way of a protected lobby (or protected corridor) in basements, or in any storey that contains high fire risk areas and where the lift also delivers directly into corridors serving sleeping accommodation. Examples of high fire risk areas in this context are kitchens, lounges and stores. In buildings with any storey at a height greater than 20 m, lifts should be approached by way of a protected lobby (see 1.3.8).

A lift should not be continued down to serve any basement storey if it is in a building (or part of a building) served by only one escape stairway, or within the enclosures to an escape stairway which is terminated at ground level.

Sub-section 1.3 sets out restrictions on escape stairways that connect basements with the upper storeys of a building.

Lift machine rooms should be sited over the lift well whenever possible. If the lift well is within the enclosures to a protected stairway being the only stairway serving the building (or part of the building), then the machine room should be located outside the stairway if it cannot be sited above the lift well.

1.4.9.3 Lifts such as wall climber or feature lifts, which rise within a large volume such as a mall or atrium and do not have a conventional well may be a risk if they run through a smoke reservoir. In which case care is needed to maintain the integrity of the smoke reservoir and protect the occupants of the lift.

1.4.10 Electrical Installations and Protected Circuits

The electrical installation, comprising wiring, sockets, switches, fuse boards, distribution boards, circuit breakers, etc., should be installed in accordance with the National Rules for Electrical Installations (ET 101) published by the Electro-Technical Council of Ireland.

Where an electrical transformer or substation room and any associated main switch room are to be provided in a building, they should be located on the perimeter of the building with an external access door. The location on the perimeter including external access to the relevant room to be discussed with the electricity distribution system operator.

There are situations, such as in the case of fire alarm systems, emergency lighting or evacuation lifts, where continued operation of certain electrical components during a fire may be required. In this regard, the specific provisions of the appropriate design standards indicated in this Technical Guidance Document should be followed.

1.4.11 Ventilation Systems

1.4.11.1 Natural ventilation Guidance on designing for natural ventilation is contained in BS 5925: 1991, C ode of Practice for ventilation principles and designing for natural ventilation.

1.4.11.2 Mechanical ventilation and air conditioning systems Any system of mechanical ventilation should be designed to ensure that in a fire the air movement is directed away from protected escape routes and exits. In the case of a system which recirculates air, the system should meet the relevant recommendation for recirculating distribution systems in BS: 5588: Part 9 C ode of practice for ventilation and air-conditioning ductwork in terms of its operation under fire conditions.
Any system of mechanical ventilation in an assembly and recreation building should also comply with the relevant provisions below:

a. any such system serving the parts of the premises to which the public are admitted should be independent of the remainder of the premises;

b. if the premises is used for stage presentations, any such system should be designed to ensure that the air movement during performances is directed from the auditorium towards the stage;

c. any such system above a stage provided with a proscenium opening should be entirely independent of the auditorium system.

Where a pressurization system is installed, any ventilation and air conditioning systems should be compatible with it.

Guidance and additional recommendations in relation to ventilation systems in Places of Assembly are contained in Section 20 of BS 5588: Part 6: 1999.

Guidance on the design and installation of mechanical ventilation and air conditioning plant is given in BS 5720: 1979 Code of practice for mechanical ventilation and air conditioning in buildings, and on ventilation and air conditioning ductwork in BS 5588: Part 9: 1989 Code of practice for ventilation and air conditioning ductwork.

1.4.12 Refuse Chutes and Storage

a. Refuse storage chambers, refuse chutes and refuse hoppers should be sited and constructed in accordance with BS 5906: 1980. Code of practice for storage and on-site treatment of solid waste from buildings.

b. Refuse chutes and rooms provided for the storage of refuse should:

• be separated from other parts of the building with fire-resisting construction (refer to Section B3), and

• not be located within protected stairways or protected lobbies;

c. Rooms containing refuse chutes, or provided for the storage of refuse, should be approached only by way of a protected lobby provided with not less than 0.2 m2 of permanent ventilation, to the outside of the building.

d. Access to refuse storage chambers should not be sited adjacent to escape routes or final exits or near to windows of dwellings.

1.4.13 Fire Safety Signs

Signs to indicate escape routes, including any doorways or exits which provide access to the means of escape, are required in all buildings, except within dwellings. They should be illuminated by means of natural lighting, artificial lighting or by emergency escape lighting, as appropriate (see 1.4.8), so that they are clearly visible and distinguishable by the occupants of a building.

Signs should be provided to indicate the position of fire-fighting equipment (see 1.4.16) and fire alarm call points (see 1.4.14), where provided.

Signs, in accordance with BS 5499: Part 5: 2002, should be provided on fire doors (see Appendix B), except those held open by electromagnetic devices connected to the fire alarm, to indicate that they should be kept shut.

Attention is drawn to possible additional requirements for fire safety signs under the Fire Services Act, 1981, when the building is in use.

Attention is also drawn to Statutory Instrument, S.I.

No. 132 of 1995 Safety, Health and Welfare at Work (Signs) Regulations, 1995. These Regulations require the provision of emergency and other signs in a place of work, as defined in the Safety, Health and Welfare at Work Act, 2005. T he shape, colours and pictogram (to convey the appropriate safety message) for the signs are prescribed in those Regulations. The relevant emergency escape and fire-fighting equipment signs may be used for the purposes of this Section (B1). Other signs, which may be required when the building is in use, are outside the scope of the Building Regulations.

1.4.14 Fire Detection and Alarm Systems

1.4.14.1 Introduction The occurrence of fire in a building could lead to a situation where conditions become untenable and escape routes become unusable. It is likely that these conditions will not occur until some time after the initiation of the fire and the sooner the outbreak is detected, the more time will be available for evacuation, should this be necessary.

Buildings should be provided with a fire detection and alarm system to warn the occupants of the existence of fire where the building is of such a size, layout or occupancy that the fire itself may not provide adequate warning to the occupants so as to enable them to escape safely.

Where a fire detection and alarm system is provided, the system should comply with the recommendations relevant to design and installation contained in C EN T S 54: Part 14: 2004, Fire detection and fire alarm systems - Guidelines for planning, design, installation, commissioning, use and maintenance (European) or I.S. 3218: 1989, C ode of practise for fire detection and alarm systems for buildings – system design, installation and servicing. The type of system provided should be appropriate to the uses of the building and for protection of life (types L and M systems). Guidance on the fire detection and alarm systems for certain building types is contained in the following paragraphs.

1.4.14.2 Residential (Institutional) buildings In most types of residential (institutional) buildings, a high level of protection is required and a type L1 fire detection and alarm system should generally be provided. In the design of such systems, consideration should also be given to the category of occupant, evacuation procedures and means of alerting the emergency services.

Guidance on the provision of fire detection and alarm systems in hospitals is contained in Fire code Health Technical Memorandum 82 Alarm and detection systems, 1996.

1.4.14.3 Mixed-user buildings A fire detection and alarm system should be provided in buildings which contain a number of different occupancy types or uses. The type of system and the degree of protection provided should be appropriate to the nature of the occupancies and to the building size, layout and construction.

1.4.14.4 Buildings containing flats or maisonettes In a building containing flats, or maisonettes, Purpose Group 1(c), individual dwellings (except open plan flats) should be provided with a fire detection and alarm system complying with the provisions set out in 1.5.5 of this Document (a maisonette should be treated as a two storey dwelling house for this purpose).

Open plan flats should be provided with a fire detection and alarm system complying with the provisions set out in 1.6.3(d) of this Document.

In addition to alarms within individual dwellings, in a building containing flats where the flats are accessed by common protected corridors / lobbies / stairways, a common fire detection and alarm system should be provided. It should be designed to provide adequate warning in the case of fire.

This system should not be connected to any alarms within individual dwellings provided in accordance with 1.5.5 or 1.6.3(d).

It should consist of:

• a heat detector in each flat, located adjacent to the entrance door to the flat,

• a sounder in each flat, meeting the requirements of EN 54-3, located in the circulation area, not more than 5 m from any bedroom door,

• smoke detectors and sounders in all common escape routes, and

• smoke or heat detectors (as appropriate) in ancillary accommodation.

The system design should incorporate measures to reduce the risk of false alarms or misuse and provide for a means of control so that a pre-determined response leading to the evacuation of the building can be initiated.

Consideration could also be given, particularly in large buildings, to a system which initially warns the occupants in the areas of the building most likely to be affected by the fire.

1.4.14.5 Where an atrium is designed in accordance with BS 5588 Part 7: 1997 C ode of practice for incorporation of atria in buildings, then the relevant recommendations in that code for the installation of fire detection/alarm systems for the design options selected should be followed.

1.4.15 Provisions for People with Disabilities

Where access for people with disabilities is provided to a building or part of a building in accordance with Part M of the Second Schedule to the Building Regulations, provision should also be made, in the building or part of the building (as the case may be) for appropriate means of escape for such people.

This provision also applies to buildings containing flats.

The principles underlying the design of the means of escape from a building are based on the assumption that in the event of an outbreak of fire it may be necessary to evacuate all or part of a building. Normally the evacuation will be to a place of safety outside the building, but in some cases it may be necessary to initially evacuate to a place of relative safety within the building. The management of evacuation forms an important part of the fire safety strategy for a building. While there are no provisions in the Building Regulations in relation to fire safety management (see 0.1.7), the guidance in this Document assumes that an adequate level of fire safety management will be provided when the building is in use.

In any building there may be people with disabilities which impair their mobility or limit other faculties such as sight and hearing. The evacuation of such people require special consideration. In addition, it may be necessary to consider any special requirements in the provision of fire detection and alarm systems (see 1.4.14).

Guidance on the provision of means of escape for people with disabilities is contained in BS 5588: Part 8:1999 Fire precautions in the design and construction of buildings, Part 8, Code of practice for means of escape for disabled people. The principles outlined in BS 5588: Part 8: 1999 are based on the provision of refuge areas and the management of evacuation. Refuge areas are areas within a building, separated by fire-resisting construction and provided with a safe route to a storey exit, where people with disabilities can await assistance for their evacuation.

Refuge areas may be within the enclosure of an escape stairway, within a protected lobby or corridor leading to an escape stairway or in a compartmented part of a storey (see 3.2) which contains an escape stairway. A lift may be used for evacuation where it meets the criteria outlined inspection 10 of BS 5588: Part 8.

Refuge areas in buildings containing flats should be provided in a place of relative safety, within the enclosure of a common protected stairway, or within any protected corridor / lobby, adjacent to the stairway. This protected corridor / lobby should not provide direct access to a flat or to ancillary accommodation and should provide direct access to the stairway.

Part M of the Second Schedule to the Building Regulations provides for access to buildings for people with disabilities. Technical Guidance Document M provides guidance on compliance with the requirements of Part M.

1.4.16 First-Aid Fire-Fighting Equipment

First-aid fire fighting equipment is provided in buildings to be used by the occupants, with appropriate training and where it is safe to do so, in the early stages in the development of a fire. This equipment may be a fixed installation, such as a hose reel or may be portable fire extinguishers. Portable fire extinguishers are excluded from the provisions of the building regulations but may be required when the building is in use for the purpose of the Fire Services Acts, 1981 and 2003 and the Safety, Health and Welfare at Work Act, 2005.

A hose reel consists of a length of tubing fitted with a shut-off nozzle and attached to a reel, with a permanent connection to a pressurized water supply. Hose-reels conforming to I.S. EN 671: Part 1: 1995 should be provided in a building, where the floor area exceeds 500 m2, which is used as a shop (purpose group 4(a)), a shopping centre (purpose group 4(b)), industrial (purpose group 6) or for storage (purpose group 7(a), 7(b)). The installation of hose reels should comply with the relevant recommendations in BS 5306: Part 1: 1976 Fire extinguishing installations and equipment on premises, Part 1 Hydrant systems, hose reels and foam inlets.

1.4.17 Heat Producing Appliances

Heating boilers, cookers, fires for heating and other appliances which burn liquid, gaseous or solid fuel can provide a source of ignition for fires in buildings. In this regard, critical items include:

• the location of appliances in relation to escape routes;

• the provision of suitable and adequate flues, chimneys and hearths as appropriate;

• the provision of suitable and adequate ventilation;

• the provision and storage of fuel supplies.

Part J of the Second Schedule to the Building Regulations contains requirements in relation to heat producing appliances. Technical Guidance Document J - Heat producing appliances, provides guidance on how to comply with Part J of the Regulations.

Some of the documents referred to in sub-section 1.1, contain guidance in relation to heat producing appliances and building services generally. T he measures may also relate to provisions appropriate to Section B3, Internal Fire Spread (Structure).

1.5 Dwelling Houses

Introduction

1.5.1 This section deals with the means of escape provisions in Residential (Dwellings), dwelling houses (Purpose Groups 1(a) and 1(b) in Table 0.1).

Note: the means of escape provisions for Residential (Dwellings) flats and maisonettes (Purpose Group 1(c) in Table 0.1) are indicated in 1.1.2.

Dwelling houses will generally have a single escape stairway and there is a risk that this may become unusable due to smoke. Protection/enclosure to the stairway is required, to an extent which varies with the number of storeys above the ground level. Windows, if suitably located and constructed, can in some situations provide an alternative means of escape. With increasing height, windows become unsuitable for escape but may be useful for rescue purposes. Early warning of fire can be achieved by the provision of an appropriate smoke detection and alarm system.

The means of escape provisions for dwelling houses are outlined in 1.5.2 and 1.5.8. 1.5.7 deals with loft conversions in existing dwelling houses and 1.5.8 contains general provisions for dwelling houses.

Dwelling Houses with no Floors more than 4.5 m above ground level (Purpose Group 1(a))

1.5.2 The following provisions apply to dwelling houses where the height of the top storey is not more than 4.5 m (see Appendix C , Diagram 38). This type of dwelling house typically has one or two storeys:

a. any habitable room which is an inner room should be provided with a window for escape or rescue in accordance with 1.5.6.

b. a stairway serving an upper storey should be enclosed with storey-height construction, which need not be fire-resisting, and should discharge directly to the open air;

c. a fire detection and alarm system should be provided, in accordance with 1.5.5; and

d. the provisions in 1.5.8 should be complied with.

An open-plan arrangement, where the stairway rises directly from the ground storey accommodation is less preferable than the arrangement at (ii) above and is only acceptable where:

a. the stairway discharges to within 4.5 m of a door at the ground storey leading directly to the open air;

b. the stairway does not discharge into a kitchen and either:

• any ground storey kitchen is enclosed in storey height construction which need not be fire resisting or;

• where the stairway passes within 3 m of the kitchen, the stairway should be enclosed in storey-height construction which need not be fire-resisting;

c. a fire detection and alarm system is provided, in accordance with 1.5.5;

d. all habitable rooms at the upper storey are provided with windows for escape or rescue in accordance with 1.5.6; and

e. the design meets the general provisions for dwelling houses, outlined in 1.5.8.

Dwelling Houses with one Floor more than 4.5 m above ground level (Purpose Group 1(b))

1.5.3 The following provisions apply to dwelling houses where there is one storey which is at a height of more than 4.5 m (see Appendix C , Diagram 38). T his type of dwelling house will typically have three storeys above ground level:

a. a habitable room should not be an inner room unless

• it has a floor level not more than 4.5 m above ground or access level; and

• it is provided with a door or window for escape or rescue which complies with the provisions of par. 1.5.6;

b. unless the top storey is separated from the lower storey by fire-resisting construction (refer to B3 and Appendix A) and is provided with an alternative escape route leading to its own final exit, the internal stairway should:

• be a protected stairway (see 1.4.2 and Tables A1, A2);

• connect the ground and all upper storeys; and

• either deliver directly to a final exit (Diagram 9(a)) or give access to not less than two independent escape routes delivering to alternative final exits (see Diagram 9(b));

c. automatic smoke detection and alarms should be provided in accordance with 1.5.5; and

d. the general provisions for dwelling houses, outlined in par. 1.5.8 should be met.

Dwelling Houses with more than one Floor more than 4.5 m above ground level (Purpose Group 1(b))

Diagram 9 Alternative arrangements for escape via the ground storey in dwelling houses with floors more than 4.5 m above ground level

1.5.4 The following provisions apply to dwelling houses where there are more than one storey at a height of more than 4.5 m (see Appendix C , Diagram 38). T his type of dwelling house will typically have four or more storeys above ground level:

a. a habitable room should not be an inner room unless

• it has a floor level not more than 4.5 m above ground level and

• it is provided with a door or window for escape or rescue which complies with the provisions of par. 1.5.6;

b. all upper floors should be served by a stairway which should

• be a protected stairway (see 1.4.2 and Tables A1, A2);

• connect the ground and all upper storeys; and

• either deliver directly to a final exit (see Diagram 9(a)) or give access to not less than two independent escape routes delivering to alternative final exits (see Diagram 9(b));

c. an alternative escape route by way of an escape stairway should be provided from each storey which has a floor 7.5 m or more above the ground or access level. W here the access to the alternative escape route is by way of the protected stairway, the protected stairway at or about 7.5 m above ground or access level should be separated from the lower storeys or levels by fire resisting construction;

d. automatic smoke detection and alarms should be provided in accordance with par. 1.5.5; and

e. the general provisions for dwelling houses, outlined in par. 1.5.8 should be met.

Fire Detection and Alarm Systems for Dwelling Houses

1.5.5 A fire detection and alarm system can significantly increase the level of fire safety in a dwelling house and should be provided in accordance with the following guidance.

BS 5839: Part 6: 2004, Fire detection and alarm systems for buildings, Part 6: 2004 C ode of practice for the design and installation of fire detection and alarm systems in dwellings, provides guidance on the provision of fire detection and alarm systems in dwellings. This standard refers to different grades and types of fire detection and alarm systems, which can provide varying levels of protection. The grade and system should be selected and installed in accordance with the following paragraphs.

1.5.5.1 Grades of fire detection and alarm systems The grade of alarm system should be appropriate to the size of the dwelling house, the number of storeys and the fire risk. BS 5839: Part 6: 2004 provides for different grades of systems as follows:

Grade A systems incorporate control and indicating equipment and are designed, installed and maintained in accordance with BS 5839: Part 1: 2002, but with some specific modified provisions.

Grade B systems incorporates fire detectors, fire alarm sounders and control and indicating equipment as specified in BS 5839: Part 6: 2004.

Grade C systems incorporate fire detectors and alarm sounders (which may be combined in the form of smoke alarms) connected to a common power supply with standby supply and an element of central control.

Grade D systems are based on the provision of one or more mains-powered smoke alarms each provided with an integral standby power supply. T hey may also incorporate one or more mains powered heat alarms each with an integral standby power supply.

All smoke alarms and heat alarms should be interconnected so that detection of fire by any one unit provides an audible alarm from each.

The grade of the system should be at least Grade D as described above. Guidance on the selection of grades of system for other situations, where the fire risk and size of the building so warrants, is contained in BS 5839: Part 6: 2004.

Note: Grade E and F type systems, which are based only on battery or mains-powered smoke and heat alarms, are not acceptable for new dwelling houses.

1.5.5.2 Fire detection and alarm system types Dwelling houses should be provided with an LD1 or an LD 2 fire detection and alarm system in accordance with BS 5839 Part 6: 2004 designed for the protection of life.

An LD1 system incorporates suitably located and interconnected detectors throughout the dwelling house, including all circulation areas that form part of the escape route and in all rooms and areas in which a fire might start, other than toilets, bathrooms and shower rooms.

An LD2 system incorporates suitably located and interconnected detectors in all circulation areas that form part of the escape route and in all rooms or areas, such as kitchens and living rooms, that present a high fire risk.

Heat detectors should be provided in kitchens.

Dwelling houses with up to three storeys above ground level should have at least an LD2 system. Dwelling houses with more than three storeys, large houses, or where the fire risk so warrants, should be provided with LD1 systems as appropriate, which will provide a higher level of life safety. Guidance on system types for different situations is contained in BS 5839: Part 6: 2004.

1.5.5.3 Installation of smoke and heat alarms Two types of self-contained smoke alarm, an optical type and an ionisation type, which have differing smoke response characteristics, are available. A mixture of both types is recommended and in the case of a typical two storey dwelling house, an optical type on the ground floor storey and an ionisation type on the upper floor is the most appropriate.

The number and location of smoke alarms and heat alarms will be determined by the system type (see 1.5.5.2). In circulation areas, no door to a habitable room should be further than 7.5 m from the nearest smoke alarm. T he location of smoke alarms, particularly in relation to doorways to bedrooms and the spacing of units, should be such as to ensure that the audibility requirements specified in BS 5839: Part 6: 2004 will be achieved.

Smoke and heat alarms should preferably be fixed to the ceiling, at least 300 mm from any wall or light fitting. The method of fixing and location/spacing should take into account instructions provided by the manufacturer of the alarms.
It should be possible to reach all smoke and heat alarms to carry out, easily and safely, routine maintenance such as testing and cleaning.

Instructions on maintenance requirements should be provided with all smoke alarm systems.

Windows for Escape or Rescue

1.5.6 Windows may provide an alternative means of escape or may be used for rescue purposes in dwelling houses of limited height. As an alternative, a door which gives direct access to a balcony or roof, which is suitable for rescue by ladder or for escape may be used. Where provision is made in this subsection for windows for these purposes (see paragraphs 1.5.2, 1.5.3, 1.5.7.6 and 1.5.8.2), such windows should comply with the following:

a. The window should have an openable section which can provide an unobstructed clear open area of at least 0.33 m2 with a minimum width and height of 450 mm (the route through the window may be at an angle rather than straight through). The opening section should be capable of remaining in the position which provides this minimum clear open area.

b. The bottom of the window opening should be not more than 1100 mm and not less than 800 mm (600 mm in the case of a rooflight) above the floor, immediately inside or beneath the window or rooflight. As an exception to the general guidance in TGD K (Stairways, Ladders, Ramps and Guards) that guarding be provided for any window, the cill of which is less than 800 mm in height above floor level, guarding should not be provided to a rooflight opening provided in compliance with this paragraph.

c. In the case of a dormer window or rooflight, the distance from the eaves to the bottom of the opening section of the rooflight, or, where the window is vertical, the vertical plane of the window, should not exceed 1.7 m measured along the slope of the roof.

d. The area beneath the window externally should be such as to make escape or rescue practicable. For example,

• where there is a clear drop from a window in an upper storey or attic conversion, the ground beneath the window should be suitable for supporting a ladder safely and be accessible for rescue by the fire services or others.

• Where there is a roof, balcony or canopy below a window, it should be structurally adequate to support those using the window for escape or rescue.

e. The opening section of the window should be secured by means of fastenings which are readily openable from the inside and should be fitted with safety restrictors. Safety restrictors can be either an integral part of the window operating gear or separate items of hardware which can be fitted to a window at the time of manufacture or at installation. Restrictors should operate so that they limit the initial movement of an opening section to not more than 100 mm. Lockable handles or restrictors, which can only be released by removable keys or other tools, should not be fitted to window opening sections.

Loft Conversions

1.5.7 In the case of an existing two storey dwelling house to which a storey is to be added by converting the existing roof space into habitable accommodation, the following provisions (1.5.7.1 to 1.5.7.7 inclusive) can be applied as an alternative to those in 1.5.3. However, these alternative provisions are not applicable if:

a. the conversion involves raising the roof-line above the existing ridge, or

b. the new second storey accommodation exceeds50 m2 in area; or

c. the new second storey is to contain more than two habitable rooms.

In the case of an existing single storey dwelling house to which a storey is to be added by converting the existing roof space into habitable accommodation, the converted dwelling house should comply with the provisions of 1.5.2 above.

1.5.7.1 Enclosure of existing stairway The stairway in the ground and first storeys should be enclosed with walls and/or partitions which are fire resisting, and the enclosure should either:

a. extend to a final exit (Diagram 9(a)); or

b. give access to at least two escape routes at ground level, each delivering to final exits and separated from each other by fire-resisting construction and self-closing fire doors (Diagram 9(b)).

1.5.7.2 New stairways The new storey should be served by a stairway meeting the provisions in Technical Guidance Document K - (Stairways, Ladders, Ramps and Guards). The new stairway should be contained within an enclosure which is formed by extending the existing enclosure in fire resisting construction so that the new accommodation is separated from the existing stairway. Two alternative approaches are given in (a) and (b) below:

a. The new stairway may rise over the existing stairway and within the same enclosure, in which case the stairway should be separated from the new room(s) by a self-closing fire door set in fire-resisting construction.

b. The new stairway may alternatively rise from the existing room, in which case the new stairway should be separated from the existing room and the rest of the dwelling house by fire-resisting construction with a self-closing door at the top or bottom of the new stairway.

1.5.7.3 Doorways All doorways within the stairway enclosure should be fitted with a door, which in the case of an existing door to a habitable room or kitchen should be fitted with an appropriate self-closing device. Any new door to a habitable room should be a self-closing fire door (see Appendix B).

1.5.7.4 Glazing Any glazing in the enclosure to the existing stairway, including glazing in doors (whether or not they need to be fire doors), should be fire-resisting. There should be no openable glazed sections or other ventilation openings in the enclosure to the stairway.

1.5.7.5 Fire Separation of new storey The new storey should be separated from the rest of the house by fire-resisting construction (see B3, Section 3.1.6). To maintain this separation, measures should be taken to prevent smoke and fire in the stairway from entering the new storey.

1.5.7.6 Escape windows The room (or rooms) in the new storey should each have an openable window or roof-light for escape or rescue purposes which meets the relevant provisions in 1.5.6 above.

1.5.7.7 Fire detection and alarm systems. Automatic smoke detection and alarms should be provided throughout the dwelling house in accordance with 1.5.5 above.

General Provisions for Dwelling Houses

1.5.8 The following general provisions apply to dwelling houses.

1.5.8.1 Inner rooms An inner room is where the access to that room is through another room. A habitable room should not be an inner room unless it is located at basement, ground or first storey and is provided with a window or door suitable for escape or rescue in accordance with the provisions of 1.5.6.

1.5.8.2 Windows for escape or rescue Windows may provide an alternative means of escape or may be used for rescue purposes in dwelling houses. Guidance in relation to such windows is given in Paragraph 1.5.6. T here are specific situations, e.g. as described in Paragraphs 1.5.2, 1.5.3 and 1.5.7.6, where windows in dwelling houses should comply with the guidance given in Paragraph 1.5.6 in this regard.

As a general provision, in addition to the specific situations referred to above, all bedrooms in dwelling houses, other than bedrooms with doors that give direct access to the outside at ground level, should comply with the provisions outlined in Paragraph 1.5.6.

Where windows are being replaced in existing dwelling houses, it is recommended that bedroom windows should meet, in as far as is practicable, the provisions outlined at 1.5.6. In the case of other habitable rooms, opening sections should not be reduced or altered to an extent that reduces their potential for escape or rescue.

1.5.8.3 Heat producing appliances Heat Producing appliances include cookers, boilers and open fires which are designed to burn oil, gas or solid fuel. These appliances are a potential source of ignition for fires and it is important that they are correctly installed in dwelling houses. In this regard, critical items include:

• location of the appliance, particularly in relation to escape routes;

• suitable and adequate flues, chimneys, fireplaces and hearths as appropriate;

• suitable and adequate ventilation;

• fuel supplies.

Part J of the Second Schedule to the Building Regulations contain requirements in relation to heat producing appliances. Technical Guidance Document J - (Heat Producing Appliances), provides guidance on the above items and on how to comply with Part J.

Where a ducted warm air heating system is provided in a dwelling house, precautions should be taken to ensure that it will not contribute to fire spread or endanger the enclosure to any stairway. BS 5588: Part 1: 1990 (Section 6) contains appropriate guidance on these measures.

1.5.8.4 Electrical installations The electrical installation, comprising wiring, sockets, switches, fuses, distribution board, circuit breakers, earthing, etc., should comply with the National Rules for Electrical Installations produced by the ElectroTechnical Council of Ireland.

1.5.8.5 Basements Basements, where provided in dwelling houses, should be separated from the ground floor storey by means of fire-resisting construction. A stairway serving an upper storey should not extend down to the basement storey.

Any basement habitable room which is an inner room or basement bedroom should be provided with an alternative means of escape.

The fire detection and alarm system (see 1.5.5) should be extended to include any basement areas.

1.6 Open Plan Flats Introduction

1.6.1 This section provides additional guidance (see 1.1.2) for means of escape provisions for open plan flats, which are accessed directly from a common protected corridor / lobby, or an open balcony / deck approach.

The provisions of 1.6.3 do not apply to small, single staircase buildings (see 1.1.2), where a flat is accessed directly from the stair, which relies upon the internal protected entrance hall for lobby protection to the staircase enclosure.

1.6.2 General requirements. Where an open plan flat is provided, each door between the flat and a protected corridor / lobby, or an open balcony / deck approach, should have a fire resistance equal to the fire resistance of the wall, but not more than 60 minutes, in accordance with Appendix B.

1.6.3 Internal Layouts. The means of escape requirements in open plan flats are determined by the maximum travel distance within the flat. Where the travel distance is less than or equal to 9 m, the provisions of 1.1.2 apply. Where the maximum travel distance exceeds 9 m, and where the appropriate alternate means of escape (see 1.1.2) has not been provided, the following provisions apply (see Diagram 9A):

Diagram 9A Open plan flats

a. a sprinkler system in accordance with Section

b. the flat should be situated on a single storey only,

c. the travel distance from any point in the flat to the final exit from the flat should not exceed 20 m,

d. a Fire Detection and Alarm System should be provided. It should consist of interconnected self-contained mainspowered / battery backed Smoke / Heat Alarms (Grade D), which should be provided in the following locations:

• all circulation areas that form part of an escape route within the dwelling,

• all high fire risk areas/rooms e.g. kitchen, living rooms, utility rooms,

• and all bedrooms,

e. and the kitchen:

• should be enclosed in storey height construction, which need not be fire resisting, or

• if not enclosed, the flat layout should be designed such that an occupant escaping the flat should not have to approach within 1.8 m of the main kitchen cooking appliance.

A main kitchen cooking appliance is a cooking apparatus with a fixed connection to the dwelling's gas or electric energy infrastructure (for example, an oven and/or hob).

1.7 Protected Corridors / Lobbies Serving all Flats

Introduction

This section provides additional guidance (see 1.1.2) for protected corridors / lobbies which provide means of escape from flats.

1.7.1. Corridor / Lobby Travel Distances in Buildings with a Single Stairway

All common protected corridors / lobbies which have direct access to a flat should be ventilated by means of a smoke control system.

An exception to this requirement is a building with a topmost floor level of less than 11 m.In such a building, where a smoke control system is not provided, the maximum travel distance (see 1.1.2) is 4.5 m.

The maximum travel distance in a protected corridor / lobby provided with a smoke control system (see 1.7.2), irrespective of the topmost floor level, is 7.5 m.

Where every flat to a protected corridor / lobby on the same storey is provided with a sprinkler system (see 1.8), and the same protected corridor(s) / lobby(s) are provided with a smoke control system, the travel distance on that storey can be further extended up to a maximum of 15 m.

The travel distance should be measured from the furthest entrance door to a flat to the protected stair, or lobby door. The lobby should provide direct access to the stair and should not provide direct access to a flat or ancillary accommodation.

1.7.2 Smoke Control System for Protected Corridors / Lobbies

A smoke control system for a protected corridor / lobby is installed to facilitate escape in corridors / lobbies. The smoke control system should be designed to ventilate the protected corridor / lobby for means of escape. The smoke control system should be activated by means of an appropriate fire detection and alarm system.

The smoke control system should consist of (a), (b), or (c), as follows:

(a) an automatic opening vent having a clear openable area of not less than 1 m2 fitted at the top of the stairway enclosure, and an automatic opening vent(s) (AOV) from the protected corridor / lobby to the exterior of the building, which should be in accordance with the following:

• it should have a minimum free area of 1.5 m2,

• it should be fitted as close to the top of the ceiling of the protected corridor / lobby as is practicable, but be at least as high as the top of the door connecting the protected corridor / lobby to the stairwell or lobby.

Where there are multiple AOV’s due to multiple corridors, the system should be designed to activate the relevant AOV only. The AOV’s from the common protected corridors / lobbies on all other floors should remain closed.

b. an automatic opening vent having a clear openable area of not less than 1 m2 situated at the top of the stairway enclosure, and an automatic opening vent to a natural smoke shaft, which should be in accordance with 1.7.3 below.

c. a mechanical smoke control system which has a proven equivalent performance to (a) or (b) above.

In a building with a floor level at more than 20 m above ground level, the provision of an adequate smoke control system to a protected corridor / lobby may be sufficient to ventilate the firefighting lobby (see 5.3).

Where any smoke control system is powered by electricity, the system should be capable of operating at all material times.

1.7.3 Natural Smoke Shafts in buildings containing Flats

Natural Smoke Shafts in buildings containing flats should be closed at the base. Replacement air is provided from the automatic opening vent in the stairwell to help the efficiency of the shaft system.

Natural smoke shafts should meet the following specific recommendations:

• the smoke shaft should have a minimum cross-sectional area of 1.5 m2 (minimum dimension 0.85 m in any direction),

• the minimum ventilation area from the common protected lobby or corridor into the shaft, and at the opening at the head of the shaft, and at all internal locations within the shaft (e.g. safety grilles) should be at least 1 m2,

• the top of the protected corridor / lobby vent should be located as close to the ceiling of the protected corridor / lobby as is practicable, and should be at least as high as the top of the door connecting the protected corridor / lobby to the stairwell or lobby,

• the shaft should extend a minimum length of 2.5 m above the ceiling of the highest storey which is served by the shaft, the opening at roof level should be at least 0.5 m above any surrounding structures within a horizontal distance of 2.0 m,
  the smoke shaft should be constructed in accordance with 3.2.7.1,

• the ventilation openings from the common protected lobby or corridor to the vent shaft should achieve the same fire performance as the shaft, but not exceeding 60 minutes,

• no services other than those relating to the smoke shaft should be contained within the smoke shaft,

• the shaft should be vertical from base to head but may have not more than 4 m at an inclined angle not more than 30o from the vertical plane,

• the design of the system should be such that, on activation of the fire detection and alarm system, the ventilator on the fire floor, the ventilator at the top of the smoke shaft and the 1 m2 ventilator at the head of the stairway should all open simultaneously.

Where there are multiple shafts due to multiple corridors, the system should be designed to activate the relevant shaft only. The ventilators from the common protected corridors / lobbies on all other floors, and unaffected corridors on the fire floor should remain closed.

1.8 Domestic Sprinkler Systems

Introduction

This section provides guidance in relation to sprinkler systems in buildings containing flats.

1.8.1 Where a sprinkler system is provided, it should be in accordance with BS 9251:2014, or equivalent. The system should have the following as minimum requirements:

a. a minimum duration of operation of 30 minutes,

b. a flow rate of 4 mm/min for single head operation, or 2.8 mm/min through each sprinkler operating simultaneously up to a maximum of two sprinklers in a single area of operation,

c. a primary and an alternative power supply,

d. a duty and standby pump, and

e. an on-site water storage capacity, suitable to meet the flow requirements and duration of the system, but not less than 3 m3.

An isolation valve should be provided to each individual flat. It should be located within the flat, near to the main entrance door, and should be readily accessible.