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Part B Fire Safety Volume 2 dwelling houses

B6 Means of warning and escape in case of fire

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B6 A dwelling house shall be so designed and constructed that there are appropriate provisions for the early warning of fire and there are adequate means of escape in case of fire from the dwelling house to a place of safety outside the building, capable of being safely and effectively used.

1.1 Means of warning and escape in case of fire

1.1.1 General

The purpose of the requirement of Regulation B6 is to ensure that adequate early warning of fire is provided and a satisfactory standard of means of escape is provided for persons in the event of fire in a building.

1.2 Performance

The requirement of B6 may be met:

(a) If there is a route or routes of sufficient 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 an alarm system to warn the occupants of the existence of fire is 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.

1.3 Dwelling Houses

1.3.1 Introduction

This section deals with the means of escape provisions in Dwelling houses (Purpose Groups 1(a), 1(b) and 1(d) in Table 0.1).

Note: The means of escape provisions for Residential (Dwellings), flats and maisonettes (Purpose Group 1(c)) are contained in TGD B Volume 1: Buildings other than Dwelling Houses.

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.

The means of escape provisions for dwelling houses are outlined in 1.3.2 -1.3.5 and 1.3.9 contains general provisions for dwelling houses. Appendix D deals with loft conversions in existing dwelling houses.

Early warning of fire can be achieved by the provision of an appropriate smoke detection and alarm system. Guidance on an appropriate system for dwellings is outlined in 1.3.6.

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

The following provisions apply to dwelling houses where the height of the top storey is not more than 4.5 m (see Diagram 3(a) or 3(b) and Appendix C, Diagram C4). 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 1.3.7.

(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 1.3.6; and

(d) The provisions regarding escape and rescue in 1.3.7 should be complied with.

(e) The general provisions in 1.3.9 should be complied with.

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

(a) the stairway discharges to within 4.5 m of a door (final exit) at the ground storey leading directly to the open air;

(b) the stairway does not discharge into a kitchen (see Diagram 1(a)) and either;

  • any ground storey kitchen, where the cooking facilities are within 3 m of the stairway is enclosed in storey height construction which need not be fire resisting (see Diagram 1(b)) or ;

  • where the stairway passes within 3 m of the cooking facilities, the stairway should be shielded to the foot of the stairs with ceiling – height construction which need not be fire-resisting;(see Diagram 1 (c))

(c) a fire detection and alarm system is provided, in accordance with 1.3.6

(d) all habitable rooms at the upper storey are provided with windows for escape or rescue in accordance with 1.3.7; and

(e) the design meets the general provisions for dwelling houses, outlined in 1.3.9.

Diagram HB1 - Open plan arrangement for escape - Extract from TGD B Vol. 2
Diagram HB1 - Open plan arrangement for escape - Extract from TGD B Vol. 2

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

The following provisions apply to dwelling houses where there is one storey which is at a height of more than 4.5 m (see Diagram 3(c) & Appendix C, Diagram C4). This 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 1.3.7.

(b) unless the top storey is separated from the lower storey by fire-resisting construction (refer to S3 and Appendix A and Diagram 2(b)) and is provided with an alternative escape route leading to its own final exit, the internal stairway should:

  • be a protected stairway (see 1.3.8);

  • connect the ground and all upper storeys; and

  • either deliver directly to a final exit (Diagram 2 (a)) or give access to not less than two independent escape routes delivering to alternative final exits (see Diagram 2(b));

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Diagram HB2 - Alternative arrangements for escape via the ground floor in dwelling houses with floors more than 4.5 m above ground level - Extract from TGD B Vol. 2

(c) automatic smoke detection and alarms should be provided in accordance with 1.3.6;

(d) The provisions regarding escape and rescue in 1.3.7 should be complied with; and

(e) the general provisions for dwelling houses, outlined in par. 1.3.9 should be met.

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

The following provisions apply to dwelling houses where there are more than one storey at a height of more than 4.5 m (see Diagram 3(d) and Appendix C, Diagram C4). This 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. 1.3.7;

(b) all upper floors should be served by a stairway which should;

  • be a protected stairway (see 1.3.8);

  • connect the ground and all upper storeys; and

  • either deliver directly to a final exit (see Diagram 2(a)) or give access to not less than two independent escape routes delivering to alternative final exits (see Diagram 2(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. Where 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;(see Diagram 4)

(d) the provisions regarding escape or rescue in par. 1.3.7 should be complied with for all floors below 7.5 m;

(e) automatic smoke detection and alarms should be provided in accordance with par.1.3.6; and

(f) the general provisions for dwelling houses, outlined in par.1.3.9 should be met.

(g) Where a dwelling house is constructed using timber frame construction, an automatic sprinkler system should be installed in accordance with BS 9251: 2014: Fire sprinkler systems for domestic and residential occupancies – Code of practice.

Diagram HB3 - Means of escape from dwelling houses - Extract from TGD B Vol. 2
Diagram HB3 - Means of escape from dwelling houses - Extract from TGD B Vol. 2

Diagram HB4 - Fire separation in dwelling houses with more than one floor over 4.5 m above ground level - Extract from TGD B Vol. 2
Diagram HB4 - Fire separation in dwelling houses with more than one floor over 4.5 m above ground level - Extract from TGD B Vol. 2

1.3.5 Community Dwelling Houses (Purpose Group 1(d))

The provisions contained in paragraphs 1.3.2 or 1.3.3 and 1.3.9 as appropriate are applicable to Community dwelling houses. In addition to these general requirements, these dwelling houses are:

(a) limited to 3 storeys.

(b) limited to a maximum of 8 bedrooms none of which should be an inner room.

(c) required to have all escape routes protected by fire resisting construction irrespective of the height of the dwelling.(see Appendix A).

(d) required to have a Fire Detection and Alarm System designed to comply with a minimum category LD1 Life safety system in accordance with I.S. 3218. Additionally a fire alarm control switch should be installed in conjunction with the LD1 FDAS to facilitate testing of the system.

(e) required to have a self-contained emergency luminaire in corridors, hallways, landings and stairways. The emergency luminaire should:

  • provide horizontal illuminance on the floor along the centre line of an escape route of not less than 1lux and the central band consisting of not less than half of the width of the route shall be illuminated to a minimum of 50% of that value;

  • provide full luminance within 5 seconds of the failure of the normal lighting supply;

  • maintain the level of luminance for not less than 3 hours; and

  • be provided with batteries rated for at least 4 years normal operation.

(f) required to have fire doors to all protected stairways and corridors in accordance with Appendix B.

Further guidance is available in: “Fire safety in Community Dwelling Houses :Code of practice for fire safety in new and existing Community Dwellings Houses ” published by the Department of Housing Planning Community and Local Government.

1.3.6 Fire Detection and Alarm Systems

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 I.S. 3218:2013: Fire Detection and Alarm Systems for Building: System Design, Installation Commissioning, Servicing and Maintenance. This standard provides guidance on the provision of fire detection and alarm systems in dwellings. It 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.

1.3.6.1 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. I.S.3218 provides guidance in this respect.

In general the following provisions are appropriate to satisfy the requirements of B6:

Grade D system: An installation of self contained mains-powered smoke or heat alarms each provided with an integral standby power supply. Where multiple units are provided all devices shall be interconnected so that detection of fire by any one unit will provide an audible alarm from each unit.

For Grade D installations interconnections may be by radio or wiring. Where radio interconnection is used, manufacturer's recommendations on testing of signal strength/reception at each device shall be carefully followed and records kept.

1.3.6.2 Fire detection and alarm system types

Dwelling houses should be provided with a fire detection and alarm system as follows:

  • Category LD2 system for purpose group 1(a) and 1(b)

  • Category LD1 for purpose group 1 (d)

or better in accordance with I.S.3218 designed for the protection of life.

Category LD2: Interconnected self-contained mains powered/battery backed Smoke/Heat Alarms (as Grade D above) shall be suitably located in:

(1) all circulation areas that form part of an escape route within the dwelling, and

(2) all high fire risk areas/rooms e.g. kitchen, living rooms, garages, utility rooms and

(3) all bedrooms.

Where professional rooms, (see 1.3.9.6) are provided the FDAS should also cover this area.

Category LD1: Includes all those areas specified in LD 2 but also includes all rooms and areas (including attics/lofts/other spaces) in which a fire might start ,other than toilets, bathrooms and shower rooms.

1.3.6.3 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 1.3.6.2).

Smoke /heat alarms should be sited according to the following provisions:

(a) In circulation areas, no door to a habitable room should be further than 7.5 m from the nearest smoke alarm.

(b) 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.

(c) 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.

(d) A heat detector is to be provided in kitchen areas in accordance with the relevant provisions of I.S. 3218: 2013.

Note: This guidance applies to ceilings that are predominantly flat and horizontal.

1.3.6.4 Any new extension to an existing dwelling house should have a Fire Detection and Alarm System in accordance with 1.3.6.2.

Where the following conditions apply, and where an extension creates one or more habitable rooms a Fire Detection and Alarm System should be provided throughout the whole dwelling house:

(a) the rear garden is enclosed

(b) the only escape route is through a room in the dwelling house and

(c) the provisions in Diagram 5 are not met.

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Diagram HB5 - Ground storey exit into an enclosed space - Extract from TGD B Vol. 2

1.3.6.5 Loft Conversions

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 1.3.2.

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 converted dwelling house should comply with the provisions of 1.3.3.

1.3.6.5.1 The provisions in Appendix D may be applied as an alternative to those in 1.3.3 where the new second storey accommodation does not:

(a) exceed 50 m2 in area; or

(b) contain more than two habitable rooms.

1.3.7 Windows for escape or rescue

1.3.7.1 General

Windows may provide an alternative means of escape or may be used for rescue purposes in dwelling houses of limited height.

As a general provision, all bedrooms in dwelling houses, other than bedrooms with doors that give direct access to the outside should have at least one window which complies with the provisions herein.

As an alternative, a door which gives direct access to a balcony 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 paragraph 1.3.2, 1.3.3, 1.3.4 and 1.3.5) such windows should comply with the following:

(a) The window should have an openable section which provides an unobstructed clear open area of at least 0.33 m2. The height should be not less than 450 mm. The width should be not less than 450 mm. 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 in the case of a rooflight not less than 600 mm above the floor, immediately inside or beneath the window or rooflight.

(c) As an exception to the general guidance in TGD K that guarding be provided for any window, the cill of which is less than 800 mm in height above floor level, (where the external ground level is below 1.4 m below floor level), guarding should not be provided to a rooflight opening provided in compliance with this paragraph.

(d) 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.

(e) 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, conservatory, balcony or canopy below a window for escape or rescue, it should be structurally adequate to support those using the window.

(f) The opening section of the window should be secured by means of fastenings which are readily openable from the inside. In certain circumstances safety restrictors may be fitted to such windows see TGD K Section 2.7. Lockable handles or restrictors, which can only be released by removable keys or other tools, should not be fitted to window opening sections for escape or rescue.

1.3.7.2. Replacement Windows Where windows are being replaced in existing dwelling houses, bedroom windows should meet, in as far as is practicable, the provisions outlined at 1.3.7.1 (a) to (e) above. 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.

1.3.8 Escape stairways

Escape stairways should comply with the requirements of Section 1 of Technical Guidance Document K - Stairways, Ladders, Ramps and Guards, to the Building Regulations, 2014.

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.

Where an escape stairway is a protected stairway the performance requirements for the enclosure are indicated in Appendix A (Tables A1).

1.3.9 General Provisions for Dwelling Houses

1.3.9.1 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 1.3.7.

1.3.9.2 Heat producing appliances

Heat producing appliances include cookers, boilers, stoves 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. 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.

1.3.9.3 Ducts

Where a ducted warm air heating system or a Mechanical Ventilation with Heat Recovery system or similar 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, particularly with regard to protected stairways, BS 9991: 2015 Fire Safety in the Design, Management and use of Residential Buildings: Section 6, paragraph 35, contains appropriate guidance on these measures. (see also S3- Internal Fire Spread).

It is not recommended to connect cooker hoods to Mechanical Ventilation with Heat Recovery systems. Where cooker hoods are connected the guidance under fire precautions in BRE Digest 398 “Continuous mechanical ventilation in dwellings” should be followed.

1.3.9.4 Electrical installations

The electrical installation, comprising wiring, sockets, switches, fuses, distribution board, circuit breakers, earthing, etc., should comply with ET101:2008: National Rules for Electrical Installations produced by the Electro-Technical Council of Ireland.

1.3.9.5 Basements

Basements, where provided in dwelling houses, should be separated from the ground floor storey by means of fire resisting construction.

Where a dwelling house is provided with a basement, all floors should be served by a protected stairway unless the basement rooms have an alternative means of escape. 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 should include the basement areas.

1.3.9.6 Professional Rooms

In the case of P.G.1(a) and P.G.1(b) any surgery, consulting rooms, offices or other accommodation not exceeding 50m2 forming part of the dwelling house and used by the occupant of the dwelling house in a professional capacity should be provided with a smoke alarm as part of the domestic alarm system, an emergency light and escape signage.

1.3.9.7 Final Exits

Any final exit door in a dwelling house or a door which gives direct access to a balcony as provided in 1.3.7 should be provided with simple fastenings (thumb latches or other readily openable mechanism) which can be operated from the escape side without the use of a key.

1.3.9.8 Fire Doors

Any door between a dwelling house and a garage should be an E30Sa or FD30S in accordance with the requirements of Appendix B.

1.3.9.9 Galleries

A gallery should be treated as a storey and a dwelling house with a gallery should comply with sections 1.3.2, 1.3.3 or 1.3.4. Where all of the following conditions are complied with the gallery need not be considered a storey:

(a) it is not designed for use as a sleeping area;

(b) the gallery should not project into more than 50% of the area of the room below (see Diagram 6 );

Diagram HB6 - Gallery floors with no alternative exit - Extract from TGD B Vol. 2
Diagram HB6 - Gallery floors with no alternative exit - Extract from TGD B Vol. 2

(c) the distance between the foot of the access stair to the gallery and the door to the room containing the gallery should not exceed 3 m;

(d) the distance from the head of the access stair to any point on the gallery should not exceed 7.5 m; and

(e) any cooking facilities within a room containing a gallery should either:

  • be enclosed in storey height construction which need not be fire-resisting; or

  • be not less than 3 m from the stair to the gallery and positioned such that they do not prejudice the escape from the gallery.

Planning permission First fix Second fix External works Fire safety Ventilation Roof Heat pumps Floors Stairways External insulation Cavity wall insulation Underfloor heating Wall ties Underfloor heating pipes Air to water heat pump Air to air heat pump Air to ground heat pump Gas boiler Timber frame IS 440 Structurally insulated panels Ceiling insulation Roof insulation Suspended floor Stairs Battery storage Intermediate floors Inner leaf Attic Conversion Time and temperature Zone control Percoltion area Ground conditions Planning Two storey Three storey Air tightness Air tightness tape Fire stopping Fire mastic Fire wraps Fire board Fireline board Moisture board Tongue and groove Professional indemnity Building energy rating Energy performance certificate External wall insulation Windows Roof lights External doors Fire doors Internal doors Wall tiles Floor tiles Shower heads Ventilation Sockets Switches Eaves box Mechanical ventilation Natural ventilation Air tight membrane Vapour control layer Fire cable Sash windows Light gauge steel