The Nationally Described Space Standards
These standards were published by the governemtn in March 2015 to prevent new dwellings being constructed below acceptable room sizes and to prevent developments being constructed as 'little boxes'.
Since its publication some local Authorities have implmented policies that compliance with these standards is mandatory.
Some Local Authorities look at the standards as 'ideal guidance' but state that they would still deal with developments on individual merits. This type of stance is usually taken by Local Authorities in cities where residential development space is of a premium.
The standards deal with internal space within new dwellings and is suitable for application across all tenures. It sets out requirements for the Gross Internal Area of the new dwelling 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 heights.
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.
We as responsible Architects do also use the standards when we are designing extensions to dwellings as well as new dwellings.
Using the Space StandardThe standard gross internal areas for lower floors take into account the extra circulation space needed for stairs and circulation space to the upper floors, and deal separately with one storey dwellings and two and three storey dwellings.
Individual dwellings are expressed with reference to the Number of Bedrooms (denoted as 'b') and the number of bedspaces or people that can be accomodated in the bedrooms (denoted as 'p'). A three bedroom home with one double bedroom and two single bedrooms is therefore described as 3b4p. A three bedroom home with one double bedroom and two twin bedrooms is therefore described as 3b6p.
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 GIA 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.
Relating internal space to the number of bedspaces is a means of classification for assesment purposes only when designing new homes and seeking planning approval (if the local authority has adopted the space standards 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 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.
Whilst this standard is intended to apply to new dwellings, as a practice bpArchitecture use the same room standards when designing any extensions to existing dwellings, and will advise our Clients where rooms fall below the standards.
The Gross Internal Area of a dwelling is defined as the total space measured between the internal faces of the perimeter walls that enclose the dwelling, This includes partitions, structural elements, cupboards, ducts, flights of stars, voids above stairs. The gross Internal Area should be measured and nenoted in square metres m2.
The GRrss Internal Area in the standard is not adequate for wheelchair housing (Category 3 homes Approved Document M3) where additional internal area is required to accomodate increased circualtion and functionality to meet the needs of wheelchair households.
Min Room dimensionsThe standards also include minimum room sizes:-
- One Double [or twin] bedroom must be at least 2.75m wide, with every other double bedroom being at least 2.55m wide.
- A Double bedroom must have a floor area of at least 11.5m2.
- A single bedroom must have a floor area of at least 7.5m2 and be at least 2.15m wide.
- Any area with a headroom less than 1.5m is not counted in the gross Internal area unless used soley for storage. If the area under the stairs is to be used for storage assume 1m2 within the GIA.
- Any other area to be used for storage has a headroom 900 to 1500mm [such as under the eaves], and this space is counted at 50% of its floor area. Any area lower than 900mm should not be counted at all.
- The standards have requirements for min m2 of staorage in each type of dwelling. This is to ensure that min adequate storage requirments are included in all new dwellings.
- Built in wardrobes can be counted in GIAand bedroom floor area requirements, but shoudl not reduce the effective width of the room. Built in area in excess of 0.72m2 in a double room and 0.36m2 in a single bedroom counts towards the built in storage requirements.
- The min floor to ceilign height in new dwellings must be at least 2.3m for at least 75% of the Gross internal area.
Please speak to the practice for further detail and explanation for how the standards , minimum room sizes, and areas have been applied to your project.
We will not publish the remaining elements of the standards as these need to be applied to individual developments to meet all of the criteria and other design standards, and should not be used out of context.
Draft Technical Requirements: Furniture and Activity spaceWhen the Draft Technical Standards were published they also included minimum Furniture sizing, and minimum activity zones for inclusion in design. we do use these.
There are also published separately guidance on teh minimum space surrounding a bed that will allow a user to comfortably get into and out of the bed, we also include these standards as part of our design, these will appear as grey pecked or feint lines in the furniture plan.