Residential Dimensions


We are concerned about the number of planning applications for new dwellings and flat conversions that indicate small and poorly shaped rooms. Clear recommendations on room sizes would not only reduce the number of sub-standard applications but also provide the planning officers with an aid to considering applications.

Sub-standard properties result in a lack of concern for the property by both the occupant and the owner. Gradually the property loses value, resulting in poor maintenance, neglect and even the property being abandoned. Surrounding properties and areas are adversely affected, the consequences possibly even greater in conservation areas.

The Royal Institute of British Architects (RIBA), in housing policy statements, has recommended using guidance of room sizes and even suggested a return to ‘Parker Morris’ type standards to combat the gradual reduction in room and dwelling sizes over recent decades, caused by the growing pressure for more new dwellings.

We have therefore prepared a Residential Dimensions Guide to help applicants to prepare designs, and to assist the panel when considering planning applications. The guidance is based upon the findings of a report prepared by HATC Ltd for the GLA – see Space Standards Report.pdf

Basis of dimensions

It has been accepted that the best basis for determining residential space requirements is the required activities, use or purpose of the space, taking account of the number of likely occupants.

The areas and dimensions have been based on the London Borough of Lambeth’s Draft Residential Standards Supplementary Planning Document and a report prepared by HATC Limited for the Greater London Authority.

The number of likely occupants is determined by the number of bed spaces provided.

New dwellings and conversions should normally meet, and preferably exceed, the minimum areas. Minimum areas may need to be increased to allow for the type and size of fittings or furniture intended to be used.

Ceiling heights

All habitable rooms (rooms used for dwelling that are not solely a kitchen, utility room, bathroom, cellar or sanitary accommodation) should have a minimum floor to ceiling height of 2.3 metres, except in rooms with sloping ceilings, where at least 50% of the required floor area should be a minimum of 2.3 metres, provided the remainder of the required area is at least 2.0 metres and where in this reduced area the slope of the ceiling is 40º or greater from the perimeter of the required area. Required areas for habitable rooms exclude any area less that a floor-to-ceiling height of 2.0 metres.


Except in a single-person dwelling, the main bedroom should be large enough for twin beds, as should other double bedrooms.

Bedrooms often provide space for activities other than sleeping, dressing and storing clothes. These other activities, such as study/homework, should be considered when planning bedrooms.

Ensuite bathrooms or showers rooms do not count towards the minimum area.

Number of rooms

Each room should be separated by permanent divisions. With living rooms, dining rooms and kitchens, these are often successfully combined in some form and minimum sizes for these combinations are provided. In dwellings with four or more occupants, at least one of these rooms should be separate from the others to provide some privacy.

We consider that in a dwelling of four or more bed spaces, the living, dining and kitchen spaces should not be combined if there is no other room available for privacy.

Overall size of dwellings

An overall minimum size for a dwelling has been indicated. The minimum area includes the provision of ancillary accommodation and circulation spaces.

Activities do not always take place in the expected place, and living patterns change over time. Therefore spaces need to provide flexibility.

Also, people’s amount of furniture and other contents increases over time, so dwellings need to provide ‘room for growth’.

The additional space can be accommodated wherever the designer thinks it appropriate to meet the intended purpose. Additional beneficial space can often be gained by careful planning and good shaping of rooms.

‘Minimum’ or ‘at least’

In the Residential Space Standards documents, ‘at least’ refers to dimensions or provisions where a shortfall will result in comments or objections, and ‘minimum’ to those that must be met for the planning application to be accepted.

Residential Dimensions Guide

Areas are in square metres, where the bold numbers are ‘minimum’ dimensions, and the non-bold numbers are ‘at least’ dimensions:

  Bed Spaces   1a 2 3 4 5 6 7
  Bed Rooms No.   1 1 2 2 3 3 5
  Living room   12 12 14 14 15 16 17
  Dining room   - 5 6 6 7 7 7
  Kitchen   6 6 8 8 8 9 10
  Living/Dining   - 15.5 17.5 18.5 18.5 19.5 20.5
  Dining/Kitchen   10.5 10.5 12.5 12.5 13 14 15
  Living/Din/Kitch   22 22 24 27 30b 33b 36b
  Main bedroom   8 12 12 12 12 12 12
  Other doubles   - - 11.2 11.2 11.2 11.2 11.2
  Single bedrooms       7.5 7.5 7.5 7.5 7.5
  Bathroom & WC   3.5 3.5 3.5 3.5 3.5 3.5 3.5
  Storage   1.0 1.25 1.5 1.75 2.0 2.25 2.5
  Overall floor areas   37 45 60 67 81 92 105

a  Only acceptable in new build housing in special circumstances.
b  Not recommended.

To avoid awkwardly shaped rooms:

Living rooms should have a minimum width of 3.2 metres
Double/twin bedrooms should have a minimum width of 2.6 metres
Single bedrooms should have a minimum width of 2 metres
All bedrooms should have a minimum length of 3 metres

At the planning application stage, applicants should provide details of proposed overall floorspace and a breakdown of room sizes.

Bedroom numbers are based on all being double bedrooms except for where one single can make up the number of bed spaces required. If more single bedrooms are used to make up numbers, then the minimum overall space required will be increased.