HMO Conversions St John's Wood

HMO work in St John's Wood is more likely to involve shared flats and older conversions than family houses. With 90% of homes here flats and only 10% houses, few houses are available to turn into shared homes. What does arise is a flat or house let to sharers that now needs a licence, or an old converted building that Westminster treats as an HMO. Westminster's renewed Additional HMO Licensing Scheme covers the whole city, so the work is building to its standards.

In St John's Wood, 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 St John's Wood: 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.

Planning use class for a shared house in St John's Wood

A family house let to three to six unrelated sharers moves from Class C3 to Class C4, and Class L of the General Permitted Development Order permits that change unless an Article 4 direction removes it. Ask Westminster whether any such direction covers your St John's Wood address before you commit. Class L does not allow one house to become two or more separate C4 HMOs, so splitting a building into several shared units is a planning application.

Above six occupants the use is sui generis, which the London Plan glossary confirms, and planning permission is needed. The London Plan also asks boroughs to take account of the role HMOs play in meeting housing need and to protect HMOs of a reasonable standard. A small C4 HMO can return to a single house under Class L, but a large sui generis HMO needs permission to change, and that London Plan protection is part of the test.

Housing in St John's Wood

For St John's Wood the Council Tax list gives about 8,840 homes; by type 90% flats and 10% houses, by age 46% post-war, 31% interwar and 23% older than 1919.

HMO licensing schemes that cover St John's Wood

Three licensing layers can apply, and in St John's Wood a flat shared by just three people can already need one. The mandatory layer catches a large HMO, which GOV.UK defines as a home let to 5 or more people who form more than 1 household. The second layer is Westminster's renewed Additional HMO Licensing Scheme, designated on 21 April 2026, in effect from 31 August 2026 and running to 30 August 2031. It reaches any shared house or flat in the city where three or more occupants, from at least two households, use a common kitchen or bathroom.

Westminster first introduced additional licensing on 30 August 2021, so a licence held under the old scheme needs checking against the renewed one. Its property types include flat shares, bedsits and some converted flats outside mandatory licensing. Separately, the Selective Licensing Scheme applies in 15 wards to privately rented homes not already licensed as HMOs. The landlord or their agent applies for the licence; we build to the conditions Westminster attaches.

Mandatory licensing does not reach a flat in a purpose-built block of three or more self-contained flats; where such a flat is shared, it is the council's additional scheme, if any, that applies.

Westminster HMO standards for bedrooms and kitchens in St John's Wood

Room sizes and shared amenities are the first things the works have to meet. Westminster keeps four sets of HMO standards for different types of shared property, updated in April 2021, and it can write works conditions into a licence to bring a property up to them. For a St John's Wood flat share, the shared house and flat standard is the one that applies. Under it, the kitchen can be no smaller than 5.5 square metres and must be laid out for safe use, and a bedroom sleeps two people at most, with children counted.

Bedroom sizes are a legal minimum too. The national minimums, conditions of every mandatory HMO licence, are 6.51 square metres for one adult and 10.22 for two, and no room under 4.64 may be slept in. Where a statutory HMO bedroom size is breached, Westminster says it must act, but it gives the landlord 18 months to put the room right. For a St John's Wood flat share with a small box room, that period is the time to move a partition, merge two rooms or change a room to a study. We measure every room at the survey so the layout meets the standard before the licence conditions arrive.

Fire safety and old conversions in St John's Wood

In an older building, fire protection comes first on an HMO works list. Under Westminster's HMO standards, a building converted entirely into self-contained flats still counts as an HMO if the conversion work falls short of the 1991 Building Regulations and long leaseholders hold under two thirds of the flats. An older St John's Wood villa split into rented flats can land in that group. Westminster adds that a converted building with no shared facilities can still need a mandatory or additional licence if some flats are not fully self contained.

In those buildings, Westminster's self-contained flat HMO standard names 60 minutes fire resistance as the building regulations benchmark, but in most existing conversion flat buildings 30 minutes is accepted with appropriate automatic fire detection. A fire risk assessment then sets the works, following the LACORS housing fire safety guidance: self-closing fire doors to each letting, detection in the flats and the common parts, and an escape stair kept clear. Sound insulation between lettings and an EPC of E or above for letting are planned in the same programme.

• Interlinked smoke and heat alarms, mains-wired and graded to the council's HMO fire guidance
• Sound lining to bedroom walls and party walls
• Small HMO conversions for three to six sharers

VOA Council Tax stock of properties, March 2025, for St John's Wood North and St John's Wood South. Counts rounded by the VOA.

Useful next reading for a hmo conversions project in St John's Wood: bathroom renovation in St John's Wood, hmo conversions across Westminster, what a main building contractor does, kitchen fitting in London, our London hmo conversions page and Getting Planning Permission.

Working With GS Renovation in St John's Wood

We build HMO upgrades and conversions to the licence conditions and planning consent your agent secures, with one site lead and a written programme listing each fire, amenity and room size item against the standard it meets. A structural engineer designs any new openings. A registered electrician certifies the wiring and the fire alarm installation. We work room by room where tenants remain in occupation, and hand over the certificates and drawings the licence application asks for.

• Honest updates if a date or a detail has to move
• Fire doors, closers and seals fitted to every door on the escape route
• Article 4 and licence position checked before a room is priced

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