The changes in the regulations aim to reduce unwanted solar gain by “the appropriate sizing and orientation of windows, and shading measures”, and to limit internal temperature using “the thermal mass of the structure to absorb excess heat in daytime and release it at night”. To comply, designers will have to show, by calculation, that internal temperatures will not be excessive. And if designers are looking to keep temperatures down by introducing air-conditioning, the government has that option covered, too.
“Heating, ventilation and air-conditioning are included in the regulations for the first time,” says Ant Wilson of consultant Oscar Faber. “Designers will have to justify the use of air-conditioning using performance standards. As long as it is not wasteful, they can put it in.”
The proposals call for performance standards for buildings (larger than 200 m2 in floor area) that are air-conditioned or mechanically ventilated. To comply with the regulations, designers will have to use a new method of calculation called a carbon performance index. This will allow the efficiency of the ventilation system to be assessed and will “eliminate a significant proportion of office practice that currently falls short of good practice”, states the document.
Other changes to the regulations affecting building services include the proposal to introduce requirements for the commissioning of heating, hot water, ventilation, air-conditioning and lighting to ensure the systems work as they were designed. The onus will be on installers to certify that they have commissioned the systems to standards laid down by the Chartered Institution of Building Services Engineers. As in domestic installations, installers will be required to provide information to occupiers on how to operate their services efficiently.
The job of the commissioning engineer will be made easier by the new requirement to install meters to monitor energy consumption. Initially, this will provide building occupiers with the facility to monitor system performance, but is primarily intended for building occupiers to report and publish energy data under future changes to the regulations. New performance standards for boilers, heating and hot-water systems should also see big improvements in efficiency.
The efficiency of lighting will also be included. Display lighting was excluded from the lighting provisions introduced in 1995 but will now be covered, as will light fittings.
- Further increases in fabric U-values
- Changing the method for calculating U-values
- Further improvement in the envelope standards
- Mandatory air-tightness testing of dwellings
- The introduction of new powers under the Building Act to bring existing housing under the regulations
- Control of over-heating in dwellings
- Guidance on limiting boiler sizing
- Promoting the use of combined heat and power plants