HMO Conversions Brentford

HMO conversion in Brentford is shaped by one borough-wide rule: Hounslow's Article 4 Direction removed the right to turn a family house into a small HMO without planning permission from 4 September 2023. On top of that, Hounslow's additional licensing scheme has covered HMOs with three or more people in two or more households since 11 December 2025. We build shared houses to the approved plans and the licence standards: room heights, kitchens and bathrooms, fire doors, detection and escape routes.

If the building is listed, the works themselves are a separate question: anything that affects its character, inside or out, needs listed building consent from Hounslow Council, and carrying it out without consent is a criminal offence.

In Brentford, a light HMO conversion for four to six tenants typically costs £40,000 to £75,000 in construction, or £90,000 to £150,000 with an en-suite to every bedroom (indicative London ranges, Mayfair Studio and LetCompliance, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Brentford: we build the fire doors, detection, bathrooms and kitchens to the council's HMO standards, the landlord applies for the licence, and a registered electrician certifies the electrics.

Hounslow's HMO Article 4 and a Brentford family house

A Brentford house cannot become a small shared house under permitted development. Class L of the General Permitted Development Order 2015 normally allows a change from a C3 dwellinghouse to a C4 HMO, but Hounslow's borough-wide Article 4 Direction, confirmed on 8 August 2023 and in force from 4 September 2023, removes that right. The exclusions it names are open land, industrial areas, Chiswick Business Park, Bedfont Lakes Business Park and the Mogden Sewage Works, none of them a residential street in TW8.

Size decides the planning route after that. The London Plan glossary defines HMOs for three to six people as Use Class C4 and HMOs for more than six people as sui generis, so seven or more sharers need a full application in any event. Class L also does not permit one former house to become two or more separate C4 HMOs. Your agent or designer makes the application, and the room count on the approved drawings is the count we build to.

Housing in Brentford

Of the 13,230 homes the valuation list records in Brentford, 15% were built before 1919, 24% between the wars and 61% since 1945; 65% are flats and 35% are houses.

Where Hounslow supports larger HMOs, and what that means in Brentford

Hounslow's HMO SPD says HMOs that need planning permission should have at least PTAL 4 public transport accessibility and be within a 400m walk of town centre facilities. Brentford is one of the borough's District Centres, so a house close to its shops and Brentford station is better placed against that test than one on the edge of the area. The PTAL score of a specific address comes from Transport for London's mapping, and your designer checks it before drawings start.

The London Plan asks boroughs to take account of the role of HMOs in meeting housing needs, and says HMOs of a reasonable standard should generally be protected. It also asks boroughs weighing C3 to C4 Article 4 Directions to consider the strategic as well as local importance of HMOs. For a Brentford landlord, an application is therefore judged on location and quality together, so the standard of the rooms, kitchens and bathrooms shown on the drawings matters from the start.

Licensing a Brentford HMO under additional and mandatory schemes

A Brentford HMO with three or more people in two or more households falls under licensing. Hounslow's additional licensing scheme was designated on 11 September 2025, has applied borough-wide since 11 December 2025 and ceases to have effect on 10 December 2030 unless revoked or extended. Mandatory licensing covers HMOs of five or more people forming two or more households who share a kitchen, bathroom or toilet, so a larger house sits under both regimes.

The mandatory scheme stops short of flats in purpose-built blocks of three or more self-contained flats, which only an additional licensing scheme can catch.

The landlord applies, not the builder. A Hounslow licence normally lasts five years, but a one-year licence is normally issued where there are concerns about management or condition, or deliberate avoidance of licensing. GOV.UK says renting out an unlicensed HMO can lead to an unlimited fine, and Hounslow names financial penalty notices among the consequences of breaches. Our part is to build the house to the licence conditions, so a licensing inspection finds nothing left to put right.

Room standards and fire safety in a Brentford HMO

Hounslow's HMO standards set the physical rules the rooms are built to. Rooms need a floor to ceiling height of at least 2.14m over 75% of the floor area, and no more than two people may share a room for sleeping, whatever their age. Newly provided bathrooms need a mechanical extractor as well as any openable window. In a licensed HMO there is no discretion, because the national minimum HMO standards, must be met: at least 6.51 square metres for one sleeper over 10, 10.22 square metres for two, and no room under 4.64 square metres used for sleeping.

Fire safety follows building regulations Part B and the LACORS housing fire safety guidance, the recognised guide for shared houses. For a Brentford terrace on two or three storeys that means fire doors with self-closers on bedrooms and the kitchen, a protected escape route down the stair, interlinked smoke and heat detection, and emergency lighting where the route needs it. Sound insulation between lettings follows, and an EPC rating of E or above is needed where the property is covered by the MEES Regulations.

• Bedroom layouts checked against the national minimum room sizes
• Sound lining to bedroom walls and party walls
• Service holes sealed so each bedroom and the kitchen stay separate fire compartments

VOA Council Tax stock of properties, March 2025, for Brentford Central, Brentford West & Osterley Park and Brentford East. Counts rounded by the VOA.

If this is your first project in Brentford, these are worth a look: bathroom renovation in Brentford, hmo conversions across Hounslow, how building control works in London, kitchen fitting in London, our London hmo conversions page and How to Choose a Builder.

The GS Renovation Difference in Brentford

An HMO conversion has to satisfy planning, building control and the licence at once, and we build to all three from one set of drawings. We work from the approved plans and the licence conditions your agent provides, check room sizes and ceiling heights on site before partitions are boarded, and install fire doors, detection and extract in the order building control needs to see them. At the end you have the fire, electrical and building control certificates your licence application asks for, and one contact for any questions the licensing officer raises.

• En-suites placed only where a soil stack can serve them
• Fire doors, closers and seals fitted to every door on the escape route
• A written scope and programme agreed before work starts

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254).