Section 6 - Community heating systems

This section provides guidance on the specification of Community Heating (CH) systems in dwellings that, if followed, will satisfy the minimum requirements of Part L of the Building Regulations.

The sections in Part L dealing with central heating and hot water systems also apply to Community Heating. Procedures for calculating the energy use and carbon emissions associated with Community Heating are included in the Dwelling Energy Assessment Procedure (DEAP).

6.1 - Scope of guidance

The guidance in this section applies to CH systems. It covers CH using boilers as the heat source as well as those that use renewable heat sources such as biofuels, heat pumps and solar panels or Combined Heat and Power (CHP),

Guidance is provided for two scenarios:

Where dwellings will be connected to a new CH scheme; and
Where dwellings will be connected to an existing CH scheme.

Guidance given in the warm air heating or underfloor heating sections is also relevant to CH where these types of space heating systems are used with CH. The remainder of this section providing guidance on CH assumes that a radiator system is employed similar to that for gas-fired central heating systems.

6.2 - Definition of Community Heating (CH)

A CH system is one that supplies heat to a number of dwellings from a common heat source. It may comprise, for example, a system heating a block of flats or a larger scale system heating many buildings. Systems that supply fewer than 15 dwellings from a central boiler system are not covered in this section of the guidance, and the guidance given for individual dwelling heating systems should be followed for these applications where appropriate.

The guidance in this document assumes that the CH distribution system uses hot water as the energy carrier. Hot water service systems may be generated centrally within each building or in individual dwellings.

Minimum provisions for connection of dwellings to a new CH scheme

In order to comply with the requirements, new CH systems to supply both new and existing dwellings should meet all of the following conditions:

The minimum provisions for system design to maximise the efficiency of heat generation and minimise energy use by pumps should be met as given in Table 21.

AND

Where the system uses low-carbon heat sources (e.g. CHP, biofuels, or heat pumps), the minimum provisions for the lead heat generator, should be met, as defined in Table 22.

AND

Where heating systems are to be installed for new dwellings, the minimum provisions for control of the system should be met as given in Table 23

AND

The minimum provisions for hot water production, storage and treatment should be met as in Table 24 (row d).

AND

The minimum provisions for the installation of heat meters should be met as given in Table 24 (row e).

AND

The minimum provisions for commissioning of the system should be met as given in Table 24 (row f).

AND

The minimum provisions for insulation of pipework should be met as given in Table 25.

Minimum provisions for connection of dwellings to an existing CH scheme

In order to comply with the requirements of, when new or existing dwellings are connected to an existing CH scheme the following conditions should be met:

Where existing CH systems are in need of replacement or improvement a specific study should be carried out to assess the economic and environmental benefits of a range of options, including the use of CHP and other renewable heat sources or chp, especially where individual heating systems are being considered as an alternative to continuing with the CH system.

AND

If thermal energy is purchased from an existing district or community heating system an assessment of the carbon intensity of the scheme should be carried out. Emission factors should be determined based on the particular details of the scheme, but should take account of the annual average performance of the whole system (i.e. the distribution circuits and all the heat generating plant, including any CHP, and any waste heat recovery or heat dumping). The calculation of the Building Energy Rating should be carried out by a suitably qualified person, detailing how the emission factors were derived.