Section 257 HMOs
Under the Housing Act 2004, there are different types of HMOs (Houses in Multiple Occupation). The two most common are:
| Type | Definition |
| Standard (Part 2) HMO | A property occupied by 3 or more unrelated people who share facilities like kitchen or bathrooms. |
| Section 257 HMO |
A building converted into self-contained flats, where: 1. The conversion did not comply with Building Regulations in force at the time and 2. More than one-third of the flats are not owner occupied. |
Unlike standard HMOs, Section 257 of the Housing Act 2004, HMOs may appear as flats but were not properly converted to modern building standards, particularly in terms of fire safety, sound insulation, and means of escape. This makes them higher-risk buildings, and subject to additional licensing and enforcement.
Section 257 HMO Policy
Under the Housing Act 2004, a building that has been converted into self-contained flats may be classified as a Section 257 House in Multiple Occupation (HMO) if it does not comply with the relevant building standards. Specifically, for buildings converted after 1991, compliance with the 1991 Building Regulations is essential to be exempt from Section 257 HMO licensing.
Where landlords cannot provide evidence that conversions meet the 1991 Building Regulations, we carry out practical inspections to assess key building features based on the standards set out in the Approved Document B (Fire Safety) 1991. These inspections focus on fire safety, sound insulation, self-contained access, and amenities to determine if the flats meet the necessary requirements.
When carrying out a Housing Act 2004 HHSRS or HMO management regulation assessment we will consider the following when assessing if a property is a S257 HMO or not.
| Building Feature | What we look for as part of our housing conditions assessment |
| Fire Seperation | Solid masonry or concrete walls/floors between flats; no thin stud walls unless multiple layers of plasterboard are evident on each side of the stood wall (two layers of plasterboard each side of the wall frame). |
| Flat Entrance Doors | FD30 fire-rated doors with self-closing devices at the flat entrance. |
| Means of Escape | Protected communal escape routes with fire doors leading to final exit. |
| Smoke Detection | Mains-wired interlinked smoke alarms installed in hallways and living areas. |
| Self - Contained Facilities | Separate kitchen, bathroom, and WC for each flat; no shared facilities between flats. Doesn’t exit into any areas shared with a HMO. |
| Seperate Services | Individual gas/electric meters and heating controls for each flat. |
| Sound Insulation | Walls and floors that provide adequate sound insulation, avoiding thin partitions. |
| Access Arrangements | Single flat entrance from communal areas; no internal shared access routes inside flats. |
Designating a building a S257 HMO
If a building does not have a minimum valid 1991 Building Regulations completion certificate that the building owner can produce, and/or our officers find that the construction does not meet the standards, the property will be classified as a Section 257 HMO and be subject to licensing requirements.
Removing facilities from a HMO to make a S257 HMO
A S257 HMO cannot be created in this way and would be considered a breach of management regulations resulting in enforcement action by the local authority.
A S257 HMO can ONLY exist from what are considered buildings converted into poor quality flats that are outside of planning enforcement.