The proposed changes to Part E of the Building Regulations, which covers acoustics, are due to be announced in November by the DETR. The changes will affect the design and construction of party walls, external walls and floors for high-density housing developments.
The proposals, which are understood to restrict the use of common building materials, were described as "quite radical" by a source close to the government.
The changes will increase the cost of high-density developments – just the type of scheme the government is trying to encourage. "All these things have cost implications," said Dave Baker, technical director at the House Builders' Federation.
Under the proposals, the use of lightweight concrete blocks will be restricted. Two layers of plasterboard will have to be installed in the walls and ceilings of timber- or steel-framed buildings, and heavy-duty wall ties will be restricted for larger wall cavities.
The proposals are also understood to include new requirements for sound insulation in external facades, to cut down on noise pollution entering dwellings from outside. But it is believed that this requirement will probably be introduced at a later date, in a tightening of the regulations.
The changes to the acoustic regulations are part of a "double whammy" of environmental regulatory changes that housebuilders will have to accept.
June saw proposed changes to Part L of the Building Regulations – the section that deals with the energy efficiency of buildings.
"It is a big frustration," Baker added. "Part L is giving us food for thought and Part E coming along later has not helped."
A source close to the DETR confirmed that housebuilders would find it difficult to comply with the both documents: "The difficulty will be in amalgamating Part E and Part L," he said.
Unlike the changes to the energy regulations, which involved consultation with industry, changes to Part E will be released as a finished document to industry for comment. "Unless there are well-founded objections, that is what the final document will be," said the source.
There are also understood to be differences in terminology between the two documents that could lead to confusion. The definition of the density of a lightweight block is understood to be different in the new Part E and in the new Part L.
How the changes will affect housebuilders
- Restrictions on the use of some lightweight blocks in wall construction
- Restrictions on the use of plasterboard on dabs on flanking walls (any wall in contact with a party wall) on any type of block
- Restrictions on use of rigid foam plasterboard laminates on dabs to flanking walls for any block type
- Restrictions on the use of plasterboard on dabs to party walls
- Two layers of 12.5 plasterboard will be required to the walls and ceilings of all framed buildings to reduce sound transmission through the walls
- Facade insulation will be required if eventual proposals include new requirements for attenuating external noise
- Use of heavy-duty wall ties for larger cavities will be restricted
- Restrictions on the use of beam and block floors for intermediate floors