Statutory guidance

Technical housing standards – nationally described space standard

Published 27 March 2015

Applies to England

Introduction

1. This standard deals with internal space within new dwellings and is suitable for application across all tenures. It sets out requirements for the Gross Internal (floor) Area of new dwellings at a defined level of occupancy as well as floor areas and dimensions for key parts of the home, notably bedrooms, storage and floor to ceiling height.

2. The requirements of this standard for bedrooms, storage and internal areas are relevant only in determining compliance with this standard in new dwellings and have no other statutory meaning or use.

Using the space standard

3. The standard Gross Internal Areas set out in Table 1 are organised by storey height to take account of the extra circulation space needed for stairs to upper floors, and deal separately with 1 storey dwellings (typically flats) and 2 and 3 storey dwellings (typically houses).

4. Individual dwelling types are expressed with reference to the number of bedrooms (denoted as ‘b’) and the number of bedspaces (or people) that can be accommodated within these bedrooms (denoted as ‘p’). A 3 bedroom (3b) home with 1 double bedroom (providing 2 bed spaces) and 2 single bedrooms (each providing 1 bed space) is therefore described as 3b4p.

5. This allows for different combinations of single and double/twin bedrooms to be reflected in the minimum Gross Internal Area. The breakdown of the minimum Gross Internal Area therefore allows not only for the different combinations of bedroom size, but also for varying amounts of additional living, dining, kitchen and storage space; all of which are related to the potential occupancy.

6. Relating internal space to the number of bedspaces 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.

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

8. The Gross Internal Area of a dwelling is defined as the total floor space measured between the internal faces of perimeter walls^{[footnote 1]} 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).

9. The Gross Internal Areas in this standard will not be adequate for wheelchair housing (Category 3 homes in Part M of the Building Regulations) where additional internal area is required to accommodate increased circulation and functionality to meet the needs of wheelchair households.

Technical requirements

10. The standard requires that:

a. the dwelling provides at least the gross internal floor area and built-in storage area set out in Table 1 below

b. a dwelling with 2 or more bedspaces has at least 1 double (or twin) bedroom

c. in order to provide 1 bedspace, a single bedroom has a floor area of at least 7.5m² and is at least 2.15m wide

d. in order to provide 2 bedspaces, a double (or twin bedroom) has a floor area of at least 11.5m²

e. 1 double (or twin bedroom) is at least 2.75m wide and every other double (or twin) bedroom is at least 2.55m wide

f. 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)

g. 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

h. 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

i. the minimum floor to ceiling height is 2.3m for at least 75% of the Gross Internal Area

Table 1. Minimum gross internal floor areas and storage (m²)

Number of bedrooms (b)	Number of bed spaces (persons)	1 storey dwellings	2 storey dwellings	3 storey dwellings	Built-in storage
1b	1p	39 (37) *			1.0
1b	2p	50	58		1.5
2b	3p	61	70		2.0
2b	4p	70	79		2.0
3b	4p	74	84	90	2.5
3b	5p	86	93	99	2.5
3b	6p	95	102	108	2.5
4b	5p	90	97	103	3.0
4b	6p	99	106	112	3.0
4b	7p	108	115	121	3.0
4b	8p	117	124	130	3.0
5b	6p	103	110	116	3.5
5b	7p	112	119	125	3.5
5b	8p	121	128	134	3.5
6b	7p	116	123	129	4.0
6b	8p	125	132	138	4.0

*Notes (added 19 May 2016)

1. Built-in storage areas are included within the overall GIAs and include an allowance of 0.5m² for fixed services or equipment such as a hot water cylinder, boiler or heat exchanger.

2. GIAs for 1 storey dwellings include enough space for 1 bathroom and 1 additional WC (or shower room) in dwellings with 5 or more bedspaces. GIAs for 2 and 3 storey dwellings include enough space for 1 bathroom and 1 additional WC (or shower room). Additional sanitary facilities may be included without increasing the GIA provided that all aspects of the space standard have been met.

3. Where a 1b1p has a shower room instead of a bathroom, the floor area may be reduced from 39m² to 37m², as shown bracketed.

4. Furnished layouts are not required to demonstrate compliance.

Footnote

1. 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. ↩