Home insulation requirements condemned as too costly as separate row over design guidance smoulders on.

THE House Builders’ Federation has attacked proposed changes to Part L of the Building Regulations, claiming that they will add £2000 to the cost of a new home.

The regulations are being changed in an attempt to reduce energy wastage in new homes. To meet the proposals, housebuilders say they will need to spend the additional money increasing the thickness of insulation in walls, floors and roofs to comply.

An HBF spokesperson said the extra cost would not result in significant savings. “The DETR changes will save the equivalent energy of just five minutes’ use of a hairdryer,” he said.He added that the extra money would be better spent on energy efficiency in houses already built.

The increases in insulation demanded by the proposed regulations are so great that the DETR intends to introduce the changes in two stages.

The first phase would come into effect in 2002 and the second in 2004.The DETR estimates that the cost to housebuilders of complying with the first phase of the proposals will be £500-800 for a semi-detached house. To comply with the second phase, the estimated cost is £400-600.

Meanwhile, in a separate row, delays in issuing design guidance to help contractors comply with the proposed changes to Part L have brought a welter of criticism from suppliers and contractors, which say the DETR has mismanaged the changes.

A source involved in the preparation of the guidance said: “There are huge problems, which is why work on the robust standard has ground to a halt.”

Materials manufacturers drawing up the DETR guidance have blamed the problems on the delay in issuing revisions to the acoustic regulations, Part E. One source said: “There is no point in issuing guidance to meet Part L if you then contravene Part E.”

One materials manufacturer said: “The thinking behind the proposed changes to the acoustic regulations will have a completely different effect on the way houses are constructed, and contradict the changes proposed in Part L.”

Proposed changes may include new acoustic insulation requirements that could rule out some contemporary wall constructions – particularly some kinds of party wall.

The BRE is working with industry working groups to produce the guidance, which is due to be published as a series of standard details to show builders how to minimise heat loss and air leakage in new buildings to comply with the proposed changes. The project is funded by the DETR.