Sound resistance

The amended Approved Document E came into force on 1st July 2003; to help you choose the right method of construction you should consider the following. The requirements apply to new build, extensions, change of use and alteration work.

Typical construction detail within a dwelling house, flat or room for residential purposes

Internal walls


  • Walls between bedrooms and other rooms.
  • Walls between toilets, not en-suites, and other rooms.

When constructing these walls from metal or timber frames the mass of plasterboard must be not less than10kg/m². To achieve this you will need to use 15mm standard plasterboard or 12.5mm fire rated or sound rated plasterboard. Two layers of plasterboard will be needed if an absorbent layer of insulation (minimum thickness 25mm, minimum density 10 kg/m3) is not provided in the cavity.

When constructing these walls from concrete block the mass of block must be not less than 120kg/m². Wall may be finished with plaster or plasterboard. When constructing these walls from aircrete block the mass of block must be not less than 90kg/m² with a plaster finish and 75kg/m² with a plasterboard finish. You cannot use this type of wall if it needs to achieve a minimum mass in relation to the type of separating wall you may have used. The wall cannot be load-bearing or rigidly fixed to separating floors.

Internal floors


  • Floors between storeys in houses.
  • Internal floor within a maisonette.
  • New floor created when carrying out a loft conversion.

When constructing these floors from timber joists:

  • The mass of the decking must be not less than 15kg/m². To achieve this you will need to use 22mm chipboard or 18mm plywood or tongue and groove floorboards.
  • The mass of plasterboard ceiling must be not less than 10kg/m². To achieve this you will need to use 15mm standard plasterboard or 12.5mm fire rated or sound rated plasterboard.
  • 100mm mineral wool insulation, not less than 10kg/m3, is required between joists.

You will need to consider effect of decking and ceiling thickness when matching existing floor and ceiling levels.

Care will be required when carrying out loft conversions as the mass of the existing ceiling may not achieve 10kg/m².

Guidelines for walls and floors that separate dwelling houses, flats or rooms for residential purposes


  • Mass and density of products that you are using.
  • The whole construction detail and how it is made up.
  • Detailing of junctions between walls, ceilings and floors.
  • Finishes, must these be wet plaster rather than plasterboard dry-lining?
  • Type of wall ties used in cavity walls.
  • Types of doors in sound resisting walls.
  • Containment of noise within noisy parts of a building.
  • Positions of sockets and flues on opposite sides of walls.
  • Sealing and filling of joints.
  • The use of cavity closers.
  • That lower standards may apply to conversion work or historic buildings.
  • Penetrations by services.
  • That sound resistance criteria apply to ‘rooms used for residential purposes’ i.e. hotels, boarding houses, hostels and other similar places.
  • Reverberation in common parts of buildings and the use of absorbent materials.
  • Design of schools.

The key to all this is the correct selection of materials and products, proper detailing of work and quality control during construction. If any changes are proposed these must be thoroughly investigated.

Sound testing

Unless plans were fully approved prior to 1 July 2003, testing will be required between rooms or spaces that share a common area of separating wall or floor as indicated below. Testing is not required for internal walls and floors within a dwelling-house, flat or room for residential purposes.

  • Dwelling-houses, flats or rooms for residential purposes created by conversion of existing buildings or new build rooms for residential purposes will need to be tested if work starts after 1 July 2004,
  • New build dwelling-houses and flats will need to be tested if work starts after 1 July 2004.

The main aim of testing is to ensure that minimum standards of sound resistance have not been compromised by poor workmanship. You will need to test all types of buildings or rooms on a random basis. Normally the first constructed of each type followed by a 10% sample of that type. If failures occur the number of tests may increase. When a failure occurs you will need to agree ways of rectifying problem with us and carry out the work prior to occupation. You will also have to show that the problem does not exist in other buildings or rooms of the same type or apply the remedial treatment to all areas.

Programming of testing is vital during construction stage to reduce the chance of delays in occupation and disruption while any remedial work is carried out.

Please note that the above is not exhaustive and is intended for guidance only. It is your responsibility to ensure all matters are covered and that methods of construction and products are appropriate for the work you are carrying out. The guidance is based on the suggestions made in Approved Document E 2003. You do not have to follow the Approved Document however if you choose to use other ways of showing compliance with the Building Regulations information will be required to substantiate your work. This may involve manufacturer’s details, independent certification and so on.

Last updated: Wednesday, 24 April, 2024.