Wall of silence

Noise disturbance is one of the most frequent complaints made by home owners and occupiers. As anyone who has suffered from a home entertainment system will testify, loud and intrusive noise drives people to distraction faster than a passing BMW playing "Thumpy, Thumpy" by The Doppler Effect.

The situation could easily become worse unless action is taken, particularly as the government's plans for urban regeneration include the use of brownfield sites for housing. For this reason the Building Regulations Advisory Committee (BRAC) has advised the Department of the Environment, Transport and Regions (DETR) to review the Building Regulations for sound insulation.

The current Part E of the Building Regulations controls the sound insulation between new dwellings and those formed by the conversion of other types of building into dwellings. A public consultation is currently under way covering the new proposals that considerably extend the scope of the current requirements.

In addition it includes measures that will improve compliance with the target performance standards.

The proposals
The consultation package includes proposals to replace the current requirements with five new ones: E1 to E5.

Requirement E1 covers sound insulation between dwellings, but also extends the scope to rooms for residential purposes. These include places where people live and sleep, such as accommodation in hotels and hostels.

Requirement E2 is a new requirement. This will provide improved sound insulation and privacy between a room containing a WC and other rooms, and also between bedrooms and other bedrooms and other rooms. The first part of the requirement is based on NHBC and Zurich Municipal standards. The second part is new.

Requirement E3 brings protection against external noise under Building Regulation control for the first time. Currently, it is carried out under the planning system, and includes site layout, the erection of noise barriers, and sound insulation measures to the building envelope.

It is proposed to leave all planning aspects of the subject with the planning authority, but to transfer responsibility for the sound installation of the building envelope to building control bodies. This will have the advantage that sound installation (Part E), thermal installation (Part L) and ventilation (Part F) will all be considered together. This should result in a more uniform treatment of the subject across England and Wales, which will be supported by official guidance in a revised Approved Document E for the first time.

Requirement E4 will control noise produced in the common parts of flats and similar buildings, which can reverberate along corridors and up stairwells, the thereby disturbing the occupants of the flats.

Requirement E5 deals with acoustics in schools. The DETR and the Department for Education and Employment (DfEE) are proposing to end the exemption of maintained schools from the Building Regulations. This will mean that all new schools (initially in England, to be followed by Wales) will come under the building control system.

For acoustics in schools, it is necessary to control the sound insulation between rooms and to protect rooms from external noise. It is also important to ensure that teaching spaces have suitable reverberation characteristics to provide good speech intelligibility. The draft Approved Document does not contained detailed guidance on the subject, but instead refers to DfEE publications.

Technical support
All the requirements will be supported by new technical guidance in a revised edition of Approved Document E. The main aim of the proposals is to improve sound insulation, and for this reason two important changes are being proposed.

First, explicit performance standards have been given, which a higher than the current implicit standards. A new rating method has been adopted which attaches more weight to insulation at low frequencies. This is due to the fact that low frequency noise is subjectively disturbing.

Second, and perhaps more important, it is proposed that pre-completion testing of the sound insulation actually achieved should be carried out on a sampling basis. Builders will be required to have the tests carried out, under the direction of the building control body, and to carry out remedial treatment where necessary before the home is occupied. Currently, although it is the builder's responsibility to satisfy the Building Regulations, occupants often have difficulty getting redress when they believe the sound insulation is poor. This proposal should ensure that the sound insulation is reasonable before the home is occupied.

A substantial part of the proposed Approved Document gives guidance on separating wall and floor constructions that should meet the new standards if built correctly. It has been necessary to make some important changes to the current designs to meet the new standards. The main changes are as follows:

• most separating walls to have a wet plaster finish
  
• beam and block floor has been removed from the guidance
  
• timber floors have been redesigned
  
• load-bearing masonry walls in flats should have a minimum mass of 120 kg/m2

The latter guidance is necessary to control flanking sound transmission along walls which pass separating walls and floors. This is the area where interaction between Part E and Part L is most likely.

The response form in the consultation document gives people who have already responded to the Part L consultation the opportunity to change any of their comments. These comments, along with other relevant comments on Part E, will be considered by groups working on both parts of the Building Regulations. The intention is to ensure there are no conflicts between the two.