Meeting the total floor area alone does not demonstrate that a home complies. [1] [2]
Start with bedrooms, people and storeys
The standard describes homes by both bedroom count and intended occupancy. It also distinguishes single-storey dwellings from homes arranged over more than one storey. A flat's floor level in a block is not its number of internal storeys. [1]
For a single-storey dwelling, examples of minimum gross internal area are:
- One bedroom, one person: 39 square metres, reducible to 37 square metres where a shower room replaces a bathroom.
- One bedroom, two people: 50 square metres.
- Two bedrooms, three people: 61 square metres.
- Two bedrooms, four people: 70 square metres. [1]
These are different accommodation types, not interchangeable labels for the same plan. A developer should not assume that a two-bedroom flat designed for three people can be advertised or assessed as a four-person layout without checking the extra requirements. [1]
Bedrooms have their own dimensional tests
A single bedroom must provide at least 7.5 square metres and be at least 2.15 metres wide. A double or twin bedroom must provide at least 11.5 square metres. At least one double or twin bedroom must be at least 2.75 metres wide; other double or twin bedrooms must be at least 2.55 metres wide. [1]
Check area and width together on the actual layout. An awkwardly shaped room may reach the area threshold while still failing its width test. Furniture drawings are also useful for showing how the intended occupants can use the space; London's housing guidance addresses functional layouts as well as numerical standards. [1] [3]
Storage is included, not added afterwards
The dwelling-area figures include an allowance for built-in storage. The standard requires one square metre for a one-person dwelling, 1.5 square metres for a one-bedroom two-person dwelling and two square metres for a two-bedroom dwelling. Storage cannot simply be omitted because the total area has been achieved elsewhere. [1]
The measurement is gross internal area within the dwelling's enclosing walls, following the standard's definition. A balcony or shared corridor is not a substitute for missing internal accommodation. For assessment, use one consistent measurement method across the plans and accommodation schedule. [1]
London has a higher ceiling-height requirement
The national standard requires at least 2.3 metres floor-to-ceiling height over at least 75% of gross internal area. London Plan D6 requires at least 2.5 metres over at least 75%. A layout designed only to the national height figure therefore does not establish London compliance. [1] [2]
Wheelchair-user homes can need additional space and different layouts. Check the accessibility category separately rather than assuming that compliance with the standard dwelling-area table also demonstrates M4(3) compliance. [1] [2]
Record the checks clearly
Use a schedule stating each home's occupancy, internal storeys, measured area, bedroom dimensions, storage and ceiling-height coverage. Keep it coordinated with the submitted plans. The draft replacement London Plan may change future requirements, but it had not replaced the adopted standards when checked on 2 October 2026. [1] [2] [4]