Flat Conversions Highgate

Flat conversion in Highgate means dividing one of the area's remaining houses into self-contained flats, or joining flats back into a single house. 69% of homes across the VOA statistical areas that cover Highgate, which run into Highgate Wood, are already flats and only 31% are houses, so the stock left to divide is limited. Planning permission is needed to turn a house into flats, and Camden's policies look at the mix of homes and any homes lost. We build the fire separation, sound insulation and services to the consent the owner secures.

In Highgate, 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 Highgate: 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.

Which Highgate houses can be split into flats

The houses worth converting in Highgate are the larger period ones. Of all homes here, 16% are terraces and 15% are semi-detached or detached, and 47% of the stock was built before 1919. A tall Victorian or Edwardian house with generous floor to ceiling heights can give two or three good flats; a narrow terrace may not give even two that meet today's standards. The first test is therefore whether each floor can hold a whole flat with daylight, a kitchen and a bathroom.

The London Plan small sites text lists residential conversions among the forms of incremental intensification that count where they result in net additional housing, so a well-planned conversion in Highgate adds to supply. It is still a material change of use from one dwelling to several, and it needs planning permission, which the owner or their designer applies for. We are brought in once the layout is settled, to price the build from the drawings and advise on sequence and buildability.

Housing in Highgate

Count the homes in Highgate and you get about 10,090: 28% built since 1945, 24% between the wars and 47% before 1919, with flats at 69% and houses at 31%. Where most homes are flats, a flat in Highgate can be split or combined only with the freeholder's consent, and changing the number of homes usually needs planning permission as well.

Camden's mix, loss and space rules for a Highgate conversion

Camden tests what kind of homes a Highgate conversion creates. Local Plan Policy H7 requires all housing development, including conversion of existing homes, to contribute to the Dwelling Size Priorities Table and include a mix of large and small homes. Policy H3 works the other way, resisting the net loss of two or more homes unless the scheme creates large homes, adapts affordable homes or enlarges sub-standard units to meet space standards. Merging three flats into one house loses two homes and falls under that policy, while merging two loses only one.

Room sizes come from London Plan Policy D6, which counts conversions as new dwellings. A one-bedspace single bedroom must be at least 7.5 square metres and 2.15m wide, and at least 75 per cent of each flat needs a floor to ceiling height of 2.5m. Camden applies the nationally described space standard flexibly where an existing building, particularly a heritage asset, constrains the layout. That standard sits in planning, not in the building regulations, so it is settled at application stage in Highgate.

Fire separation and sound testing between Highgate flats

The bulk of the build effort in a Highgate conversion goes into separating the flats. Under Part B each flat needs fire-resisting floors and walls around it, a protected route out, fire doors onto the common stair and detection. In a period house the old timber floors and lath ceilings do not meet that on their own. New fire-rated ceilings, insulation and sealed service penetrations go in throughout, and the stair enclosure is rebuilt or upgraded before any flat is finished.

Part E sets how well sound is kept between the flats. Approved Document E asks flats formed by a material change of use to reach 43 dB airborne for walls and for floors and stairs, and a maximum of 64 dB impact for floors and stairs. Pre-completion sound testing shows whether they do, so the floor build up is detailed and fitted with care. The building control route in Camden is a full plans application, because the new common parts fall under fire safety law, with a decision within 6 weeks or 2 months for complex proposals.

Services, levy and older conversions in Highgate

Each new Highgate flat needs its own services and identity. That means a separate electricity supply and meter, separate heating, water and gas arrangements, and drainage that can take several kitchens and bathrooms. New flats also need official addresses through the council's street naming and numbering process before utilities will connect them. Where a party wall is cut into or built on, the building owner serves notices under the Party Wall Act, and the programme allows for any award before that work starts.

Camden's Community Infrastructure Levy applies to proposals that add an extra dwelling, and the charging schedule places Highgate in Zone C with Hampstead, so the owner settles the levy position with their adviser before starting. Listed houses add a second consent. Camden has more than 5,600 listed buildings, and any change to a listed building needs listed building consent, separate from planning permission and covering works inside as well as out. Opening up floors for fire and sound separation in a listed Highgate house is therefore agreed in detail before we start.

• Splitting a large flat in two, or joining two flats into one
• Common hallway, stair and entrance finishes
• A kitchen and shower room fitted in every new flat

VOA Council Tax stock of properties, March 2025, for Highgate West, Highgate East and Highgate Wood. Counts rounded by the VOA.

People planning flat conversions in Highgate may also want structural alterations in Highgate, flat conversions across Camden, builders in London who take on conversions, refurbishing a flat that has already been converted, flat conversions anywhere in London and How to Choose a Builder.

Why Choose GS Renovation in Highgate

A conversion puts structure, fire separation, acoustics, drainage and several sets of services into one existing house, and each depends on the one before. We run it as one programme, building any new openings to the owner's structural engineer's design, with a registered electrician for each flat's installation, an engineer on the Gas Safe Register for gas, and one named contact for the owner. The firm is led by its founder, Abdelaaziz Saaid, who has decades of hands-on building experience. You get a written quotation from the approved drawings and a programme to plan finance against.

• Honest updates if a date or a detail has to move
• Each flat numbered and supplied before the keys are handed over
• Each flat's new electrics signed off by a registered electrician for Part P

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.