Leaked proposals to overhaul energy provisions of the Building Regulations reveals swinging changes to combat global warming
The government is planning a major overhaul of Part L of the Building Regulations, the rules governing the energy efficiency of buildings.

In a leaked Whitehall draft document, obtained by Building, it is revealed that the government plans a series of radical proposals for improving the energy efficiency of buildings, including the mandatory pressure testing of all new homes.

Possible Future Performance Standards for Part L also reveals that the government is considering:

  • Applying Part L to domestic appliances such as fridges, kettles and games consoles, so that their energy performances can be assessed.

  • Imposing minimum efficiency standards on domestic air-conditioning units.

  • Introducing tough thermal performance targets.

  • Bringing swimming pools and small conservatories within the scope of Part L.

  • Pressure tests on homes could be imposed by 2010 if the government thinks housebuilders are not following strict design guidance on building airtight homes.

The government may also increase pressure testing on non-dwellings, by making buildings of more than 200 m2 rather than 1000 m2 subject to the tests.

The government says airtightness standards in non-dwellings are likely to be much higher when the next amendment of Part L is published in 2005. Higher standards for dwellings will be set at a later date, after the ventilation regulations in Part F have been updated.

Further measures outlined in the draft document include tough new thermal performance targets, which could change the maximum U-value for external walls to 0.15 W/m2°C from the current value of 0.35.

In an attempt to improve design, more pre-completion testing may have to be carried out to ensure workmanship is of a good standard.

The idea of including domestic appliances in Part L is currently under discussion in Whitehall.

Other radical proposals for making homes more energy-efficient include the provision of "solar ready" roofs to minimise the costs of installing solar panels and the setting of performance standards for domestic air-conditioning units (see 'Government hopes to stop air-conditioning in homes' story). The document suggests that Part L will demand that expensive but energy-efficient condensing boilers are installed in all new homes.

The government also wants to increase the number of refurbished homes that are subject to Part L in a bid to improve the energy efficiency of existing stock.

The document has been sent to industry advisory bodies and will be published in October.

The Office of the Deputy Prime Minister says it expects that the published version will form the basis for discussions that will eventually lead to the development of firm amendment proposals in 2004. The final Part L will be published in 2005.

Turning the screw on U-values

Builders and materials producers will see the required standards for thermal performance rise sharply in the 2005 revision of Part L. U-values for external walls in dwellings could change from 0.35 W/m2°C to between 0.25 and 0.15 W/m2°C according to the leaked document. The values for windows, doors and rooflights are also going to be altered to between 1.8 and 1.5 W/m2°C, and those for roofs are likely to be between 0.16 and 0.08 W/m2°C. The government admits that the targets will be tough for the industry but says that if it is to meet the carbon emission pledges made at Kyoto, significant improvements will have to be made.