Flat Conversions Deptford

Flat conversions in Deptford start from a short supply of houses: across the statistical areas covering Deptford and New Cross, 15% of homes are houses and 14% are terraces, against 85% flats. Splitting one of those houses into self-contained flats needs planning permission, and Lewisham's Policy HO2 decides whether a family home can be split and how. Once your designer has the consent, we build the conversion, with the fire separation, sound insulation and separate services that make each flat a home of its own.

In Deptford, 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 Deptford: 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.

Splitting a Deptford house into flats under Policy HO2

A Deptford house can become flats only where Lewisham's policy allows it. Lewisham Local Plan Policy HO2 supports converting a single family dwelling or a 3+ bedroom unit into smaller self-contained units, including flats, only where set criteria are met. The criterion that shapes a terrace scheme most is the family unit: a house to flats conversion must re-provide a family sized unit of 3 or more bedrooms unless the property is shown to be unsuitable for family accommodation.

With terraces making up 14% of homes here, the house being split is usually a narrow one, and the family unit takes a large share of it. A common answer is a family flat on the ground and lower floors with the garden, and a smaller flat above, rather than equal units on each floor. Your designer tests that against the policy before an application goes in, and we price and programme the build to the approved plans.

Housing in Deptford

Deptford counts roughly 14,290 homes for Council Tax; 9% are older than 1919, 4% interwar and 84% post-war, with 85% flats and 15% houses. Where most homes are flats, changing the number of flats in Deptford needs the freeholder and usually planning.

Space standards for each new Deptford flat

Every flat created in a Deptford conversion counts as a new dwelling for space standards. The London Plan space standards table treats conversions and changes of use as new dwellings. Lewisham Local Plan Policy QD8 then asks housing proposals, changes of use included, to meet and where possible beat the London Plan minimum space standards. Under London Plan Policy D6, a two-bedspace double or twin bedroom must have a floor area of at least 11.5 sq.m.

Height is often the tight point in an older house. London Plan Policy D6 sets a minimum floor to ceiling height of 2.5m for at least 75 per cent of the Gross Internal Area of each dwelling, and a new acoustic floor build up takes height from the room above or below. We measure existing heights at survey and build to the section your designer has drawn, so the finished rooms still meet it. GOV.UK notes the space standard is a planning matter, not a building regulation.

Fire and sound separation between Deptford flats

The work that makes a converted Deptford house safe and quiet is the separation between the flats. Approved Document E sets sound insulation performance for flats formed by material change of use at 43 dB airborne for walls and for floors and stairs, and 64 dB maximum impact for floors and stairs. In a timber floored house that means new insulation between the joists, resilient bars and a heavier ceiling, and pre-completion sound testing once the floors and walls are finished.

Fire separation under Part B is built at the same time. The floor between flats is upgraded to the fire rating on the drawings, the shared stair becomes a protected escape route, and each flat gets a fire rated entrance door and interlinked alarms. Lewisham's building control inspectors look at fire safety along with the rest of the building regulations, so we leave these layers open for inspection before the plasterboard is finished and the decorators start.

Drains, meters and neighbours in a Deptford conversion

A second kitchen and bathroom means new drainage, and in Deptford that can bring in the public sewer. Where the property lies inside 3 metres of a public drain, or inside 1 metre of a public lateral drain, Lewisham's guidance calls for a build over agreement first. Building over or near a drain or sewer also takes the job onto a full plans application in Lewisham. We trace the drain runs at survey so both are known early.

Each new flat needs its own electricity meter, usually its own gas or electric heating, a separate water arrangement where the supplier requires it, and an official address through street naming and numbering. Where the work cuts into or builds on a party wall, the Party Wall Act applies. Lewisham treats the Act as a civil matter between neighbours and plays no part in running it. The building owner serves any notices, and the work proceeds on written consent or an award.

• Pre-completion sound testing arranged before sign-off
• Splitting a large flat in two, or joining two flats into one
• 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 Deptford North, Silwood & Pepys and New Cross & Deptford South. Counts rounded by the VOA.

Useful next reading for a flat conversions project in Deptford: structural alterations in Deptford, flat conversions across Lewisham, builders in London who take on conversions, party walls in a flat conversion, flat conversions across London and Getting Planning Permission.

Why Deptford Homeowners Choose GS Renovation

A conversion is a building control job as much as a building job, and we run it that way. The firm is led on site by a founder with over thirty years in the trade, who keeps the separating floors, walls, stairs and services in the right order. Your structural engineer designs new openings and floor strengthening, a registered electrician certifies each flat's wiring, and gas work goes to an engineer on the Gas Safe Register. After a visit to the house you receive a written quotation, then a programme that runs to completion.

• Wet rooms stacked floor over floor to keep the drainage simple
• A written scope and programme agreed before work starts
• Fire strategy for the stair and each flat entrance settled before strip-out

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.