Technical Guidance Note 28: Sound Insulation Performance Standards

Introduction

Approved Document E gives guidance on how to achieve compliance with the requirements of the Building Regulations 2000 as amended.  The standards apply to the airborne and impact sound resistance of floors and stairs, and the airborne sound resistance of walls in new-build and where there is a material change of use in an existing building.

Airborne sound includes speech, music from instruments and loudspeakers.  Impact sound consists of sources such as footsteps and furniture being moved.

Typical situations where there is a material change of use (that will require the provision of sound insulation) are:  where a building is used as a dwelling, hotel, boarding house, or contains a flat or room for residential purposes where previously it did not, or that the building contains a greater or lesser number of dwellings, or rooms used for residential purposes than it did previously.

Sound testing is required where compliance is required with paragraph E1 (Protection against sound from other parts of the building and adjoining buildings) of Schedule 1 to the Building Regulations 2000.  The person carrying out the work will need to ensure that appropriate sound insulation testing is carried out (by a test body with appropriate third party accreditation and preferably with UKAS accreditation for field measurements), and that a copy of the results is submitted to the local authority, not more than five days after the building work is complete.

The requirement for testing came into force on the 1st  July 2003, however the requirement for testing of new build dwelling-houses and flats came into effect on the 1st July 2004.

Dwelling-houses and flats – performance standards for separating walls, separating floors, and stairs that have a separating function.

E1 - Purpose built dwelling-houses and flats

Structure	Airborne sound insulation, DnT,w + Ctr dB (Minimum values)	Impact sound insulation, L’nT,w dB (Maximum values)
Walls	45	-
Floors and stairs	45	62

E1 - Dwelling-houses and flats formed by material change of use

Structure	Airborne sound insulation, DnT,w + Ctr dB (Minimum values)	Impact sound insulation, L’nT,w dB (Maximum values)
Walls	43	-
Floors and stairs	43	64

Rooms for residential purposes - performance standards for separating walls, separating floors, and stairs that have a separating function.

E1 - Purpose built rooms for residential use

Structure	Airborne sound insulation, DnT,w + Ctr dB (Minimum values)	Impact sound insulation, L’nT,w dB (Maximum values)
Walls	43	-
Floors and stairs	45	62

E1 - Rooms for residential purposes formed by material change of use

Structure	Airborne sound insulation, DnT,w + Ctr dB (Minimum values)	Impact sound insulation, L’nT,w dB (Maximum values)
Walls	43	-
Floors and stairs	43	64

E2. Protection against sound within a dwelling-house etc.

Applies only to new build.  Internal floors and internal walls between a bedroom, or a room containing a water closet, and other rooms shall be designed to provide reasonable resistance to sound.

E2 - Laboratory values for new internal walls and floors within: dwelling-houses, flats and rooms for residential purposes, whether purpose built or formed by material change of use.

Structure	Airborne sound insulation Rw  dB (Minimum values)
Walls	40
Floors	40

Note 1. The performance set out in this table does not need to be verified by testing on site.

E3. Reverberation in the common parts of buildings containing flats or rooms for residential purposes.

Applies to new build and where there is a material change of use in an existing building.

In order to reduce reverberation to reasonable levels in corridors, hallways, stairwells and entrance halls the sound absorption properties of the materials used in construction need to be considered.

A corridor or hallway is a space for which the ratio of the longest to the shortest floor dimension is greater than three.

An entrance hall is a space for which the ratio of the longest to the shortest is three or less.

Method A: Cover a specific area with an absorber of an appropriate class that has been rated to BS EN ISO11654: 1997 Acoustics – Sound absorbers for use in buildings – Rating of sound absorption.

For entrance halls, corridors or hallways, cover an area equal to or greater than the floor area, with a Class C absorber or better.  It will normally be convenient to cover the ceiling area with the additional absorption.

Method B: Determine the minimum amount of absorptive material using a calculation procedure in octave bands.  Method B is intended only for corridors, hallways and entrance halls as it is not well suited to stairwells.

Extract from BS EN ISO 11654: 1997 Table B.1

Sound absorption class	Weighted sound absorption coefficient
A	0,90; 0,95; 1,00
B	0,80; 0,85
C	0,60; 0,65; 0,70; 0,75
D	0,30; 0,35; 0,40; 0,45; 0,50; 0,55
E	0,25; 0,20; 0,15
Not Classified	0,10; 0,05; 0,00

E4. Acoustic conditions in schools.

Schools to be designed to meet the values for sound insulation, reverberation time and internal ambient noise which are given in Section 1 of Building Bulletin 93 “The Acoustic Design of Schools”.

Glossary.

Ctr - The correction to a sound insulation quantity (such as DnT,w ) to take account of a specific sound spectra.  See BS EN ISO 717 – 1: 1997 – Noise spectrum No. 2 - noise from traffic, aircraft, factories, railways and disco’s.

Absorption coefficient – A quantity characterising the effectiveness of a sound absorbing surface.  The proportion of sound energy absorbed is given as a number between zero (for fully reflective surface) and one (for fully absorptive surface).

Adjoining – means adjoining dwelling-houses, adjoining flats, adjoining rooms for residential purposes and adjoining buildings are those in direct physical contact with another dwelling-house, flat, room for residential purposes or building.

Reverberation – The persistence of sound in a space after a sound source has been stopped.

Room for residential purposes – means a room, or suite of rooms, which is not a dwelling-house or flat and which is used by one or more persons to live and sleep in, including rooms in hotels, hostels, boarding houses, halls of residence and residential homes but not including rooms in hospitals, or other similar establishments, used for patient accommodation.

Note

The provisions of Part E do not apply to applications approved without conditions prior to 1st July 2003, or where building work has commenced prior to the 1st July 2003.  See Approved Document E Section 1 for Pre-completion testing and Sections 2, 3, 4, 5 and 6 for guidance on construction details that will give compliance with the regulations.

Building Control Group
Planning Section
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Richmond Road
Worthing
West Sussex
BN11 lLF

Tel: 01903 221344

E-mail: building.control@worthing.gov.uk

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