Minimum Room Size Calculator — NDSS and Housing Act Standards

This calculator uses the Nationally Described Space Standard (NDSS) published by the Ministry of Housing, Communities and Local Government (MHCLG) and the Housing Act 1985 overcrowding standards to determine minimum room sizes.

NDSS Minimum Bedroom Sizes

• Single bedroom: 7.5 m² and at least 2.15 m wide
• Double/twin bedroom: 11.5 m² (first one ≥ 2.75 m wide; every other ≥ 2.55 m wide)

The NDSS only sets minimum areas/widths for bedrooms (plus built-in storage, a 2.3 m floor-to-ceiling height over ≥ 75% of the Gross Internal Area, and a whole-dwelling GIA table). It does not set a minimum area for living rooms, kitchens, kitchen-diners or bathrooms — the figures this tool shows for those rooms are indicative good-practice layouts, not NDSS requirements.

Indicative (good-practice) Room Areas

• Living room: ~13-23 m² depending on occupancy
• Separate kitchen: ~8 m²
• Kitchen-diner: ~11-15 m²
• Bathroom: ~3.7 m²

Housing Act 1985 Space Standard (s.326, Table II)

• < 4.65 m² (50 sq ft): not counted as a sleeping room
• 4.65-6.50 m² (50-69 sq ft): 0.5 person
• 6.50-8.36 m² (70-89 sq ft): 1 person
• 8.36-10.22 m² (90-109 sq ft): 1.5 persons
• ≥ 10.22 m² (110 sq ft): 2 persons

A child under 10 counts as 0.5 person; a child under 1 is disregarded.

References

• Nationally Described Space Standard (MHCLG, March 2015)
• Housing Act 1985, Part X — Overcrowding
• Approved Document M — Access to and use of buildings