For anyone converting a house into flats, turning offices or a warehouse into homes, or creating rooms for residential purposes in an existing building, the rules on sound changed on 1 July 2003. The revised Part E of the Building Regulations, covering resistance to the passage of sound, came into force on that date. It raised the standards for walls and floors between homes and, for conversions, introduced sound testing before completion.
What changed
- Higher performance standards. Separating walls and floors had to meet tougher figures for airborne sound and, for floors, impact sound.
- Testing before completion. For dwellings formed by a material change of use, building control would expect a sample of separating walls and floors to be tested on site. Testing for new build homes was to follow later.
- Internal walls and floors. There were new requirements for walls and floors within a dwelling, particularly around bedrooms and rooms with a toilet.
- Common parts. Some requirements now covered the acoustic treatment of common parts in blocks of flats.
The approved document recognised that existing buildings are harder to improve and set slightly lower performance values for conversions than for new build, but the standards were still demanding.
Why conversions are difficult
Older buildings rarely have the mass or separation that good sound insulation needs. Timber floors, lath and plaster ceilings and flanking paths through walls, voids and service routes all let sound through. In a listed building or a building in a conservation area, there may also be limits on what can be changed, for example where original ceilings or joinery must be kept.
Getting it right
- Survey the existing construction before the design is fixed.
- Design separating floors and walls as complete systems, including how they meet the outside walls.
- Specify materials and details clearly, and do not allow substitutions without checking performance.
- Inspect the work before it is covered up, because a small gap can undo a good design.
- Programme the tests, and allow time to put right any failures.
A failed test late in a project means opening up finished work, delay and cost. Careful design and supervision on site are far cheaper.
See our Planning and Heritage and Contract Administration services, and how we later saw a 26 apartment refurbishment from tender to final account.