Reviewed: 2 November 2026 | Applies to: England, landlords of houses in multiple occupation (HMOs) that need a mandatory licence. General information only, not legal advice. Local licence conditions can set higher standards, so always check the licence for the property.
A bedroom that is too small cannot lawfully be used as sleeping accommodation in a licensed HMO in England. National minimum room sizes have applied as mandatory licence conditions since 1 October 2018. This guide sets out the minimum floor areas, how to measure a room with or without a sloping ceiling, how occupancy limits appear on the licence, and where councils can go further than the national figures.
If you are still working out whether the property needs a licence at all, start with our HMO licensing guide, which covers mandatory and additional licensing, applications, conditions and renewal. This page answers one question only: is each bedroom big enough, and for how many people?
The national minimum sleeping-room sizes
The minimum sizes come from the Licensing of Houses in Multiple Occupation (Mandatory Conditions of Licences) (England) Regulations 2018, which added them to Schedule 4 of the Housing Act 2004. Every licence for an HMO in England must include them as conditions. The figures are:
Scroll horizontally to view all columns.
| Who sleeps in the room | Minimum floor area |
|---|---|
| One person aged over 10 | 6.51 sq m |
| Two persons aged over 10 | 10.22 sq m |
| One child aged under 10 | 4.64 sq m |
| Any room below 4.64 sq m | Must not be used as sleeping accommodation |
Three points sit alongside the table. First, a room counts as sleeping accommodation if it is normally used as a bedroom, even if it is also used for other purposes during the day. Second, visitors of an occupier do not count toward the number of people using a room. Third, the licence holder must tell the local housing authority about any room in the HMO with a floor area below 4.64 sq m.
How to measure a bedroom
Measure wall to wall, then exclude every part of the floor where the ceiling height is below 1.5 metres. Only floor area under ceiling height of at least 1.5 metres counts toward the minimum sizes above.
For a room with a flat ceiling at normal height, the usable area is simply length times width. For a room with a sloping ceiling, such as a loft room, work through these steps:
- Mark the line on the floor where the ceiling height reaches 1.5 metres. A tape measure and a spirit level held out from the slope will find it.
- Measure the length and width of the floor area on the high side of that line only.
- Multiply to get the usable area in square metres, and compare it with the table above.
- Do not include en-suite or wardrobe floor space that falls under the low part of the slope.
Common mistakes are measuring into eaves storage, counting floor under a stair bulkhead below 1.5 metres, or measuring a box room wall to wall without checking a sloping section. If the usable figure is close to a threshold, measure twice and keep a dated sketch with the measurements written on it.
Occupancy limits and licence conditions
Size is only half of the control. The licence for the property states the maximum number of people aged over 10, and the maximum number aged under 10, who may use each specified room as sleeping accommodation. Those maxima are themselves mandatory conditions, and letting a room to more people than the licence allows is a breach even if the floor area looks generous.
Where a size or occupancy condition has been breached without the licence holder knowingly allowing it, the council must notify the holder and give a period of up to 18 months from the notification to put it right. That grace period covers unknowing breaches only, and councils deal with knowing or repeated breaches through their normal enforcement routes.
Licences also carry waste conditions: the holder must comply with any household waste storage and disposal scheme set by the local housing authority. Room sizes, occupancy maxima and waste provision sit together in the same set of mandatory conditions, so check all three when you read a licence.
Councils can set higher local standards
The national figures are a floor, not a ceiling. A local housing authority can impose its own higher space standards through its HMO licensing policy or through additional licensing conditions, and many councils publish their own bedroom-size guidance with larger minima or extra rules on room shape, natural light and kitchen or bathroom sharing ratios.
Before letting a room, read the licence and the licensing policy of the council where the property sits. Where the local standard is higher than the national minimum, the local standard is the one that decides whether the room can be let as a bedroom. The room-size checker below applies the national minimum only and says so in its result.
Worked examples
Example 1: single adult room that passes. A box room measures 2.6 m by 2.8 m with a flat ceiling, giving 7.28 sq m. That is above 6.51 sq m, so it can be let as sleeping accommodation to one person aged over 10, subject to the licence maxima for that room.
Example 2: shared room that fails. A double room measures 3.2 m by 3.0 m, giving 9.60 sq m. That passes for one adult but falls short of the 10.22 sq m needed for two persons aged over 10, so it cannot be let to two adults as sleeping accommodation.
Example 3: box room that cannot be a bedroom. A small room measures 2.2 m by 1.9 m, giving 4.18 sq m. That is below 4.64 sq m, so it must not be used as sleeping accommodation at all, and the licence holder must notify the council that the room exists.
Example 4: loft room with a sloping ceiling. A loft room measures 4.0 m by 3.0 m wall to wall, or 12.00 sq m. But the slope drops below 1.5 metres across a 1.2 m strip along one side, which removes 4.8 sq m. The usable area is 7.20 sq m, which passes for one person aged over 10 but not for two.
Check a room against the national minimum
Enter the usable floor area and who would sleep in the room. This checker applies the national minimum only. It does not replace the licence or any higher local standard.
Enter the usable area and occupants to see a result.
Calculator assumptions and limits
What this checker assumes. England only. HMOs that need a mandatory licence under Part 2 of the Housing Act 2004. Figures are the national minima from the 2018 Mandatory Conditions Regulations: 6.51 sq m for one person over 10, 10.22 sq m for two persons over 10, 4.64 sq m for one child under 10, and no sleeping use below 4.64 sq m. Usable area counts only floor under ceiling height of at least 1.5 metres. Visitors of an occupier are excluded from occupant counts. A room counts as sleeping accommodation if it is normally used as a bedroom.
What it does not cover. Higher standards set by the local housing authority or the property licence, which take precedence. Mixed or larger households (for example one adult plus one child, or three or more occupants): the licence states per-room maxima for those cases, so check the licence and the council. HMOs managed by registered charities, which have a limited exemption in the regulations. Waste storage and disposal conditions, occupancy-maxima conditions, and whether the property needs a licence in the first place.
Status. General information only, not legal advice. Confirm the current licence conditions and council policy before letting a room.
Related landlord guides
HMO licensing guide: when you need a licence and what to do | Landlord regulation guide
Bottom line: in a licensed HMO in England, no bedroom may fall below the national minimum for its occupants, rooms under 4.64 sq m cannot be bedrooms at all, and the licence plus local council standards have the final word. Measure carefully, read the licence, and check the council policy before letting a small room.
Official sources
- GOV.UK: HMO and residential property licensing reform guidance for local housing authorities
- Legislation.gov.uk: The Licensing of Houses in Multiple Occupation (Mandatory Conditions of Licences) (England) Regulations 2018
- Legislation.gov.uk: The Licensing of Houses in Multiple Occupation (Prescribed Description) (England) Order 2018
- GOV.UK: Houses in multiple occupation for tenants and landlords
