Flat Conversions New Barnet

A flat conversion in New Barnet means splitting a house into self-contained flats, or putting flats back together as one house. In the wider VOA area that includes East Barnet and Hadley Wood, half the homes are already flats, and the houses, from Victorian terraces to large interwar semis, are the stock a conversion starts from. Planning permission is needed to make one house into several homes, and the London Plan space standards apply to every new flat. We build the conversion to the approved drawings: separating floors and walls, fire protection, separate services and the finishes.

In New Barnet, 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 New Barnet: 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.

Planning a New Barnet house conversion with Barnet Council

Turning one New Barnet house into two or more flats is a material change of use and needs planning permission from Barnet Council. The London Plan small sites supporting text lists residential conversions among the forms of incremental intensification that count where they result in net additional housing, so the principle is recognised. The detail is tested against the borough's own plan: the Planning Data record for the Barnet Local Plan gives a start date of 2025-03-04.

Your designer or agent checks what that plan says about conversions and family homes, and makes the application. The officer is likely to look at the size of the original house, whether a family-sized flat is kept, the room sizes and the outdoor space. Barnet's revised Community Infrastructure Levy charging schedule came into effect on 1 April 2022, and your agent should confirm whether it applies to your scheme. We price from the drawings once the flat count is settled.

Housing in New Barnet

The stock in the New Barnet and Hadley Wood statistical areas runs to roughly 10,670 dwellings, 50% of them flats and 50% houses, built 17% before 1919, 32% between 1919 and 1939 and 52% after 1945. Many homes here are flats, and changing the number of flats in New Barnet needs the freeholder and usually planning.

Space standards every New Barnet flat conversion must meet

London Plan Policy D6 applies minimum space standards to all self-contained homes, and it states that a new dwelling includes conversions and change of use. A single bedroom must be at least 7.5 sq m and 2.15m wide, and a double or twin at least 11.5 sq m. At least 75 per cent of each flat's floor area needs a floor to ceiling height of 2.5m, which counts against some low top floors.

These figures decide how many flats a New Barnet house will take. Like the Nationally Described Space Standard, these are planning standards, not building regulations, so they are tested at planning stage rather than by building control, and then built exactly as drawn. We check the drawings against the room dimensions before we price, because a partition moved on site to fit a boiler cupboard can take a bedroom under the minimum.

Which New Barnet houses suit conversion

In the VOA statistical areas covering New Barnet, East Barnet and Hadley Wood, half the homes are flats and half are houses, with terraced houses at 15% of homes and semi-detached or detached houses at 32%. Homes built before 1919 are 17% of that stock, and the older houses tend to have the taller ceilings that make the 2.5m standard easier to meet. A large semi or detached house may also have the plot width for a separate entrance to a ground floor flat.

Policy D6 asks developments to maximise dual aspect homes and normally avoid single aspect ones. Where the borough sets no higher standard, it asks for at least 5 sq m of private outdoor space for a one or two person flat plus 1 sq m per extra occupant. In a semi, the ground floor flat can take the garden while an upper flat may need a balcony or terrace. That can decide whether the garden is divided between the flats or goes with the ground floor alone.

Fire, sound and services between the new New Barnet flats

The biggest construction change in a conversion is the floor between flats. It has to resist fire under Part B and carry sound insulation under Part E. For flats formed by a material change of use, Approved Document E sets 43 dB airborne for walls and for floors and stairs, and 64 dB maximum impact for floors and stairs. In a New Barnet house with timber joists that usually means a new ceiling below, insulation between the joists and a resilient layer above.

The staircase becomes a protected escape route, with fire doors to each flat and fire-stopping around every pipe and cable that passes between them. Each flat needs its own electricity meter, a gas meter where gas is used, its own water supply and heating. It also needs a new postal address in the EN5 or EN4 district through the council's street naming and numbering service. Where work cuts into a party wall with the house next door, the Party Wall Act applies and the building owner serves the notices.

• Fire stopping round every pipe and cable through a separating floor
• Bin stores, cycle stores and external works to the planning conditions
• A consumer unit in every flat, with a registered electrician signing off each installation for Part P

VOA Council Tax stock of properties, March 2025, for the New Barnet and Hadley Wood statistical areas, which also take in East Barnet and Hadley Wood. Counts rounded by the VOA.

Two or three things usually come up alongside flat conversions on a New Barnet job: structural alterations in New Barnet, flat conversions across Barnet, a building contractor for the whole conversion, party walls in a flat conversion, our London flat conversions page and Party Wall Act Explained.

Trusted Flat Conversions in New Barnet

We build flat conversions to the consented drawings from strip out to handover: structural alterations to the design of the structural engineer we appoint, the separating floors and walls, fire protection, new services to each unit, kitchens, bathrooms and finishes. Electrics are certified by a registered electrician. We coordinate the building control inspections and the pre-completion sound test, and give your designer and agent the programme and construction details they need. You keep one site manager from the first opening up to the last certificate.

• Mains-wired, interlinked smoke and heat alarms to the approved fire strategy
• Dust screens and floor protection in occupied homes
• Every flat checked against the space standard before the layout is priced

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.