Flat Conversions Kilburn
Houses divided into self-contained flats in Kilburn, separating floors, a protected stair and separate services for every flat.
- Rated 4.9 from 31 reviews on MyBuilder
- London guide: £50,000 to £120,000
- Free site survey, itemised quote
Flat conversion work in Kilburn deals with houses that are already rare and with conversions that were done long ago. 92% of homes here are flats and 8% are houses, so a Victorian terrace still in single occupation is the exception, and Brent protects family houses through Policy BH11. Where a split is allowed, each new flat must meet the London Plan space standards and be separated for fire and sound. We carry out the building work to the planning consent and building regulations approval.
In Kilburn, converting a house into two or three flats is published at £50,000 to £120,000 including professional and council fees, and an England-wide guide puts a straightforward two-flat split at £40,000 to £80,000 in construction alone, which is the part a builder prices (indicative London ranges, Architectural Drawings and Mayfair Studio, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Kilburn: we build the conversion to the approved drawings, building control inspects the fire and sound separation, and a registered electrician certifies each flat's electrics.
Price guide
| Work | Indicative range |
|---|---|
| House into 2 to 3 flats in London, fees and build (Architectural Drawings) | £50,000 to £120,000 |
| Build cost per square metre, London (Architectural Drawings) | £1,000 to £2,000 |
| House into 2 flats, construction only, England-wide guide (Mayfair Studio) | £40,000 to £80,000 |
| Sound insulation and fire separation, England-wide guide (Mayfair Studio) | £5,000 to £15,000 |
| Separate utility connections, 3 flats, London (Architectural Drawings) | £3,000 to £6,000 |
Indicative ranges from published cost guides (Architectural Drawings and Mayfair Studio, 2026), not a quotation. Each row names its source and whether it is a London, UK or England-wide figure. Prices checked September 2026.
Quick estimate from published guides
Guide range: choose above
Brent's family house test for a Kilburn conversion
Splitting a Kilburn house starts with Policy BH11 in the Brent Local Plan. A family home with 3 or more bedrooms can only become two or more homes if every BH11 criterion is satisfied. Two of them can be measured early: the house has to measure 130 square metres or more, or be capable of an acceptable extension to reach it, and one of the new homes has to have at least 3 bedrooms. That shapes the layout before anyone thinks about kitchens or finishes.
With only 8% of homes in Kilburn being terraced houses, the remaining houses are the stock this policy is written to protect. The larger Victorian terraces are the candidates, and keeping the family unit on the lower floors with the garden is one way to meet the policy. Your architect tests the floor area and unit mix first, and we price from drawings that already satisfy it. A layout that fails BH11 is redrawn before any building cost is worth estimating.
Housing in Kilburn
Around 17,940 homes make up Kilburn on the valuation list; 92% are flats and 8% houses, and 48% date from before 1919, 2% from between the wars and 49% from after 1945. Since most homes here are flats, a flat in Kilburn can be split or combined only with the freeholder's consent, and changing the number of homes usually needs planning permission as well.
Space standards every new Kilburn flat must meet
Every flat created in a Kilburn conversion is held to the London Plan space standards, since the Plan counts conversions and changes of use as new dwellings alongside new build. For bedrooms, Policy D6 asks for 7.5 square metres and a width of 2.15m in a single, and 11.5 square metres in a double or twin. Those minimums decide where partitions can go, how many bedrooms each flat can honestly claim and whether a box room survives the redesign.
Ceiling height is the constraint that catches Kilburn lower ground and top floors. Policy D6 wants 2.5m from floor to ceiling across at least 75 per cent of each flat's Gross Internal Area. Tall Victorian ground and first floors usually help, while a low rear addition or attic counts against the 75 per cent. The same policy favours dual aspect flats, which a front and back split of a terrace floor can struggle to give, so we measure the existing heights and windows early for the designer.
Fire and sound separation between converted Kilburn flats
A house becoming flats is a material change of use, so the whole building has to meet the building regulations for the new arrangement. Part B asks for each flat to be a separate fire compartment, with fire-resisting floors and walls between flats, a fire door to each flat, a protected common stair and a suitable alarm system. In a Kilburn terrace with timber floors and lath ceilings, the existing construction rarely gives that protection without new layers.
Sound is tested, not assumed. For flats formed by a material change of use, Approved Document E asks for 43 dB airborne sound insulation through separating walls, floors and stairs, and no more than 64 dB impact sound through floors and stairs. In a Kilburn house that usually means a new ceiling on independent joists or resilient bars, mineral wool in the void and a floating layer above, and pre-completion sound testing shows whether the separating floor passes.
Services, older conversions and de-conversion in Kilburn
Each new Kilburn flat needs its own supplies. That means a separate electricity meter and consumer unit, its own heating, a water supply the owner controls, and drainage that is connected without passing through a neighbour's flat. The council's street naming and numbering service allocates the new flat addresses, which the utilities need before they fit meters. Where the works cut into a party wall, the building owner serves notice under the Party Wall Act, and that part of the job starts on the neighbour's written consent or a surveyor's award.
Older conversions bring their own issues. Brent's additional licence covers converted self-contained flats where the conversion did not meet the building regulations of its time and still does not, and fewer than two thirds of the flats are owner occupied. For a Kilburn freeholder, upgrading such a building means fire and sound work like a new conversion. The reverse, turning flats back into one house, also reduces the number of homes, so it needs planning advice before the partitions come out.
- Separate gas, electricity and water supplies for each flat
- Splitting a large flat in two, or joining two flats into one
- Separating walls built and lined for sound between flats
VOA Council Tax stock of properties, March 2025, for Kilburn West, Kilburn Park, Kilburn Grange and Kilburn East. Counts rounded by the VOA.
Trusted Flat Conversions in Kilburn
We carry out the conversion from the approved drawings: strip-out, structural alterations your structural engineer has designed, fire separation, sound insulation, new services for each flat and the finishes. Your architect and planning adviser handle planning, and we give them a clear programme and the construction details they need. You deal with one builder from the first opening up to the completion certificate, with sound testing arranged at the right stage.
- Free follow-up visit after completion if anything needs attention
- Full plans application to building control, never a building notice
- Each flat's new electrics signed off by a registered electrician for Part P
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
It's the second time I have hired George and he has been absolutely professional and the work he did resembles perfectly what I had in mind. Being an…
Saaid is the best craftsman I have worked with. He knows what he is doing from the very beginning. He has a great knowledge of construction…
FAQ
Frequently Asked Questions about Flat Conversions Kilburn
What should I budget for a flat conversion in Kilburn?
Budget the building work first: an England-wide guide gives £40,000 to £80,000 in construction for a straightforward two-flat split (Mayfair Studio, 2026), then add design, planning, building control and utility connection fees. The published London all-in figure is £50,000 to £120,000 (Architectural Drawings, 2026). Check the council's conversion policy for Kilburn first, because it decides which houses can be split at all.
Can a Kilburn house be converted into flats under Brent's policy?
Only if it passes every BH11 test. The house needs 130 square metres of floor area, or room to be acceptably extended to that size, and the scheme must keep at least one 3-bedroom home. Your architect confirms the house qualifies before detailed design starts, and we build to the permission granted.
How big must a single bedroom be in a Kilburn flat conversion?
The London Plan answer is 7.5 square metres, with a width of 2.15m. Doubles and twins need 11.5 square metres. Because Policy D6 counts conversions as new dwellings, those sizes bind a Kilburn conversion too, and we check every room against the drawings before partitions go up.
What ceiling height does each new Kilburn flat need?
London Plan Policy D6 sets a minimum floor to ceiling height of 2.5m for at least 75 per cent of each dwelling's Gross Internal Area. Loft rooms and low rear additions often fall short, so the designer places bedrooms and living rooms where the height is. We measure the existing ceilings during the first survey.
What sound insulation is needed between flats in a Kilburn conversion?
The target for converted flats is 43 dB airborne through separating walls, floors and stairs, with impact sound through floors and stairs held to 64 dB or less. Timber floors in a Kilburn terrace need a proper build-up to reach it, and sound testing confirms the result before completion.
Does each flat in a Kilburn conversion need outdoor space?
Where Brent sets no higher standard, London Plan Policy D6 asks for at least 5 square metres of private outdoor space for a 1 to 2 person dwelling, plus 1 square metre for each extra occupant. In a terrace the garden usually goes with the ground floor flat, so upper flats may need a balcony or terrace that the planning drawings show.
Can an old Kilburn conversion need a licence even as self-contained flats?
Yes, in some cases. Brent's additional licence also covers converted self-contained flats where the conversion did not meet the building regulations then in force and still does not, and less than two thirds of the flats are owner occupied. The freeholder or landlord applies, and we carry out the fire and sound upgrades the licence requires.
Does each new flat need its own address and meters?
Yes. The council's street naming and numbering service issues the new addresses, and the energy and water suppliers use them to set up separate accounts and meters. We plan the service routes during first fix so each flat's supply is independent and the meters can be fitted as soon as the addresses are confirmed.
Can flats be turned back into a single house?
They can, and the building work is often simpler than the original split: removing added partitions and kitchens, joining the services and restoring the stair. Because it reduces the number of homes, get planning advice before starting, as permission is commonly needed in London boroughs. We build to whatever is approved.
Every Service, One Team
More GS Renovation Services in Kilburn
One team for every GS Renovation service in Kilburn:
Same Service, Nearby Areas
Flat Conversions Near Kilburn
We carry out flat conversions across Kilburn and the surrounding areas. Explore a nearby location:
Ready to Start Your Kilburn Project?
Free, no-obligation quote for flat conversions in Kilburn.