Build standards

Build standards

This pages sets out two important aspects of building standards for new homes: space standards – meaning room sizes – and standards for the visitability, adaptability and accessibility of homes which are linked to room sizes, and include other issues too.

Space standards

The government’s former Department of Communities and Local Government (DCLG) issued national space standards in March 2015. You can find the document here.

This page summarises the standards, aiming to put it in plain terms, so we can form a local understanding of the national standards, particularly where they relate to visitable, accessible, adaptable homes, which you can find out more later on this page.

The national space standard deals with the issue of internal space in new dwellings of all tenures (meaning, whether they are owned, shared ownership or rented). The standard sets out requirements for the floor area of new homes according to the number of occupants. It also sets out floor areas and dimensions for key parts of the home, like bedrooms, storage space and ceiling heights. But please note – the standards are only for new homes.

The standard

Space standards are set out in the table below.

They are organised by storey height (1, 2 or 3 storeys) to take account mainly of the extra space needed for stairs if the home has more than one floor.

The standards are set out according to the number of bedrooms and the number of people that can be accommodated in the dwelling. This allows for different minimum areas to be set out which allow for various combinations of bedrooms and other rooms.

The floor areas in this standard are not adequate for wheelchair housing (see Category 3 homes in Part M of the Building Regulations, set out later on this page) – where larger areas are required to allow for increased circulation and functionality for wheelchair users.

This table sets out the minimum gross internal floor areas and storage space in (m2)

                                   1 storey (e.g. flats) 2 storey (e.g. house) 3 storey (e.g. house)        Built-in storage

  •    1 bed                                                                                 
    • 1 person                         39                      x                        x                                1.0
    • 2 person                         50                      58                      x                                1.5
  • 2 bed                                                                                 
    • 3 person                         61                      70                      x                                2.0
    • 4 person                         70                      79                      x                                2.0
  • 3 bed                                                                                 
    • 4 person                         74                      84                      90                              2.5
    • 5 person                         86                      93                      99                              2.5
    • 6 person                         95                      102                     108                            2.5
  • 4 bed                                                                                 
    • 5 person                         90                      97                      103                            3.0
    • 6 person                         99                      106                     112                            3.0
    • 7 person                         108                     115                     121                            3.0
    • 8 person                         117                     124                     130                            3.0
  • 5 bed                                                                                 
    • 6 person                         103                     110                     116                            3.5
    • 7 person                         112                     119                     125                            3.5
    • 8 person                         121                     128                     134                            3.5
  • 6 bed                                                                                 
    • 7 person                         116                     123                     129                            4.0
    • 8 person                         125                     132                     138                            4.0

The standard requires that:

The dwelling provides at least the gross internal floor area and built-in storage area set out in the table.

  1. A dwelling with two or more bed-spaces has at least one double (or twin) bedroom.
  2. In order to provide one bed-space, a single bedroom has a floor area of at least 7.5m2 and is at least 2.15m wide.
  3. In order to provide two bed-spaces, a double (or twin bedroom) has a floor area of at least 11.5m2.
  4. One double (or twin bedroom) is at least 2.75m wide and every other double (or twin) bedroom is at least 2.55m wide.
  5. Any area with a headroom of less than 1.5m is not counted within the gross internal area unless used solely for storage (if the area under the stairs is to be used for storage, assume a general floor area of 1m2 within the gross internal area).
  6. Any other area that is used solely for storage and has a headroom of 900-1500mm (such as under eaves) is counted at 50% of its floor area, and any area lower than 900mm is not counted at all.
  7. A built-in wardrobe counts towards the gross internal area and bedroom floor area requirements, but should not reduce the effective width of the room below the minimum widths set out above. The built-in area in excess of 0.72m2 in a double bedroom and 0.36m2 in a single bedroom counts towards the built-in storage requirement.
  8. The minimum floor to ceiling height is 2.3m for at least 75% of the gross internal area.


Relating internal space to the number of bed-spaces is a means of classification for assessment purposes only when designing new homes and seeking planning approval (if a local authority has adopted the space standard in its Local Plan). It does not imply actual occupancy, or define the minimum for any room in a dwelling to be used for a specific purpose other than in complying with this standard.

Minimum floor areas and room widths for bedrooms and minimum floor areas for storage are an integral part of the space standard. They cannot be used in isolation from other parts of the design standard or removed from it.

The gross internal area of a dwelling is defined as the total floor space measured between the internal faces of perimeter walls that enclose the dwelling. This includes partitions, structural elements, cupboards, ducts, flights of stairs and voids above stairs. The gross internal area should be measured and denoted in square metres (m2). The internal face of a perimeter wall is the finished surface of the wall. For a detached house, the perimeter walls are the external walls that enclose the dwelling, and for other houses or apartments they are the external walls and party walls.

Visitable, accessible, adaptable

In the past, local authorities could require housing developers to provide some specialist housing on new development sites as part of their Local Plan; for example Lifetime Homes and homes for wheelchair users.

In its review of housing standards, the government sought to reduce the burdens placed on developers in an effort to make it quicker and easier to build homes across the country.

Here, we aim to give a simple guide to the ways local authorities can secure visitable, accessible or adaptable housing, according tot he standards in place in Autumn 2017. It is not a legal guide and has been worded simply, aiming to de-mystify what can be quite a complex subject. Hopefully it gives a starting point to help us all understand how we can work to meet the housing needs of residents who need more than a “regular” home design, both now and in the future.

Building Regulations

Our national Building Regulations apply to all new build homes. This link opens an on-line version of Building Regulations Part M, in a new window.

Part M “access to and use of buildings” contains standards about visit-ability, accessible and adaptable homes, and about wheelchair homes. Visit-ability is part of the mandatory building standard which applies to all new homes. Accessible, adaptable and wheelchair standards can be required by local authorities through their Local Plans if they wish to secure some dwellings with these higher access standards.

M4(1) Visitable dwellings: requirement for new homes built to ‘visit-able dwellings’ standard, This is mandatory for all new dwellings.

M4(2) Accessible and adaptable dwellings: standard for homes to be built to an optional higher access standard. This optional higher access standard replaces the old Lifetime Homes standard.

M4(3) Wheelchair user dwellings: sets out the standard for homes to be built as wheelchair user homes, drawing a difference between ‘wheelchair adaptable’ and ‘wheelchair accessible’ as follows:

  • Wheelchair adaptable dwellings are constructed with the potential to be adapted for occupation by a wheelchair user.
  • Wheelchair accessible dwellings are constructed for immediate occupation by a wheelchair user.

Local authorities can choose whether to include a requirement for one, or a mixture of these options for wheelchair user homes within their Local Plans. If a local authority wants to include a policy in its Local Plan that sets a requirement for either M4(2) or M4(3) it can only require these optional standards if

  • it can demonstrate that the standard will address a clearly evidenced need; and
  • the viability implications of introducing the standard have been adequately considered.

Local authorities cannot impose their own locally set standards, they can only apply the national standards set out in the Building Regulations.

National Planning Policy Guidance

National Planning Policy Guidance states that Local Plan policies requiring ‘wheelchair accessible’ homes should be applied only to those dwellings where the local authority is responsible for allocating or nominating a person to live in that dwelling. This means that wheelchair accessible homes can only be required as affordable housing, whereas wheelchair adaptable homes can be a policy requirement on both market or affordable housing.

Cost impact

The government commissioned E. C. Harris to carry out a review of the cost impacts of the various new housing standards. The report was published in September 2014. On page 38, table 45 sets out a summary of costs associated with the different access standards for a range of dwelling sizes.

This indicates that larger wheelchair accessible houses are significantly more expensive to build than wheelchair adaptable houses (also, please bear in mind the report was published in 2014).

With many thanks to Anne Keogh, Housing and Strategic Planning Manager at Peterborough City Council for her help drafting this page.

If you have feedback on this brief introduction, please contact