HMO Room Size Requirements: The 6.51sqm Rule Explained

One of the most important conditions attached to any HMO licence is the minimum room size standard. The Licensing of Houses in Multiple Occupation (Mandatory Conditions of Licences) (England) Regulations 2018 set out specific minimum floor areas for sleeping rooms in licensed HMOs. Failure to comply with these standards is a breach of the licence conditions and can result in enforcement action.

---

The Minimum Room Size Standards

The 2018 Regulations prescribe the following minimum floor areas for sleeping rooms in licensed HMOs:

Room use	Minimum floor area
Sleeping room for one person aged 10 or over	6.51 square metres
Sleeping room for two persons aged 10 or over	10.22 square metres
Sleeping room used only by children under 10	4.64 square metres

These standards apply to all HMOs subject to mandatory licensing under section 55 of the Housing Act 2004. They also apply to HMOs licensed under additional licensing schemes, as additional licence conditions must meet or exceed the mandatory standards.

---

How Floor Area is Measured

The floor area is measured as the total usable floor space of the room. Areas where the ceiling height is less than 1.5 metres are excluded from the calculation. This is particularly relevant for rooms in loft conversions or attic spaces where the roof pitch reduces the usable area.

Councils may use different measurement methodologies, but the MHCLG guidance on HMO room sizes recommends measuring to the internal face of the walls, excluding fixed furniture such as built-in wardrobes.

---

Enforcement of Room Size Standards

Councils have a duty to enforce the room size standards. If a council discovers that a sleeping room in a licensed HMO is below the minimum size, it must take one of the following actions:

1. Issue a licence condition requiring the landlord to stop using the room as a sleeping room;
2. Issue an improvement notice under section 11 of the Housing Act 2004 requiring the landlord to carry out works to bring the room up to standard; or
3. Revoke the licence if the landlord fails to comply with the conditions.

Councils are also required to notify the landlord of any rooms that are below the minimum size at the time of the licence application or inspection.

---

Practical Implications for Landlords

The 6.51 square metre minimum is often misunderstood. It is not a minimum bedroom size for all rental properties, only for sleeping rooms in licensed HMOs. A property that is not an HMO (for example, a property let to a single person or a family) is not subject to the 6.51 square metre rule.

However, all rental properties are subject to the Housing Health and Safety Rating System (HHSRS), which includes space and crowding as a hazard category. A room that is technically above the 6.51 square metre threshold may still be found to present a category 1 HHSRS hazard if it is overcrowded.

---

Room Size Standards in Additional Licensing Schemes

Councils operating additional licensing schemes may impose room size conditions that are more stringent than the mandatory minimum. For example:

• Birmingham City Council requires sleeping rooms in additional licensed HMOs to meet the same 6.51 square metre standard as mandatory HMOs.
• Leeds City Council's additional licensing scheme includes room size conditions aligned with the mandatory standards.
• Bristol City Council's additional licensing scheme requires compliance with the 2018 Regulations' room size standards.

Use the Tuxa property licence checker to check the specific licensing requirements for your property, including any additional conditions imposed by the local council.

---

Fire Safety Requirements in HMOs

In addition to room size standards, HMO licences impose fire safety requirements. These are not prescribed by the 2018 Regulations but are typically included as licence conditions based on MHCLG guidance on fire safety in HMOs. Standard fire safety conditions include:

• Fire doors with self-closing mechanisms on all bedroom and kitchen doors
• Mains-wired, interlinked smoke alarms on every floor
• Emergency lighting in corridors and stairwells (for larger HMOs)
• Fire blankets and extinguishers in kitchens
• Annual fire risk assessment for larger HMOs

---

Related Guides

• Mandatory HMO Licensing: The National Standard
• What is Additional Licensing for HMOs?
• How to Apply for a Selective Licence
• Penalties for Renting Without a Licence

---

Sources

1. The Licensing of Houses in Multiple Occupation (Mandatory Conditions of Licences) (England) Regulations 2018 (legislation.gov.uk)
2. Housing Act 2004, section 55 - Licensing of HMOs (legislation.gov.uk)
3. Housing Act 2004, section 11 - Improvement notices (legislation.gov.uk)
4. MHCLG: Houses in Multiple Occupation and residential property licensing reform (GOV.UK)
5. MHCLG: Housing Health and Safety Rating System - Guidance for landlords (GOV.UK)

---

Last reviewed March 2026 by Ben Yarrow, founder of Tuxa.