Flat Conversions Bermondsey
Houses divided into self-contained flats in Bermondsey, 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 Bermondsey is shaped by Southwark's protection of family houses. Houses are 11% of the homes here, and Southwark Plan 2022 Policy P3 does not permit a single dwelling of 130sqm or less original net internal floorspace to be split into two or more homes. The candidates are therefore the larger original houses and buildings with planning permission for flats. We build to the approved scheme, from fire separation and sound insulation to finished, separately metered flats.
In Bermondsey, 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 Bermondsey: 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
Which Bermondsey houses can be split into flats
The first test for a Bermondsey conversion is the floor area of the original house. Southwark Plan 2022 Policy P3 does not permit a single dwelling of 130sqm or less original net internal floorspace to be sub-divided into two or more homes. The plan explains that the policy protects existing family housing from conversion into smaller homes unsuitable for families. With terraced houses at 10% of Bermondsey homes, the candidates are few, so a measured survey of the original floorspace comes before any design work.
Original floorspace is the figure that counts, so later additions do not lift a smaller house over the line. If your designer confirms the house qualifies, the conversion is a planning application with drawings for each new flat, and we price from those drawings. Planning permission is needed for any house split into flats, whatever its size. The older terraces, with 9% of all Bermondsey homes built before 1919, are the likeliest to be large enough, and they bring timber floors that need upgrading between flats.
Housing in Bermondsey
The stock in Bermondsey runs to roughly 27,150 dwellings, 89% of them flats and 11% houses, built 9% before 1919, 12% between 1919 and 1939 and 73% after 1945. Most homes here are flats, and changing the number of flats in Bermondsey needs the freeholder and usually planning.
Space standards every new Bermondsey flat must meet
Each flat created in a Bermondsey conversion must meet the national space standards. Southwark Plan 2022 Policy P15 applies them to new homes including conversions, and the London Plan table counts conversions and change of use as new dwellings. Under London Plan Policy D6 a single bedroom must be at least 7.5 square metres and 2.15m wide. A double or twin bedroom needs at least 11.5 square metres. Those minimums decide how many flats a house can hold before the layout is drawn.
Height is the harder test in a converted terrace. Policy P15 requires a floor to ceiling height of at least 2.5 metres for at least 75 per cent of each dwelling's gross internal area. A lower rear addition or a top floor under a pitched roof can fail that, so the survey measures ceilings room by room. Where a floor has to be lowered or a ceiling raised to meet it, a structural engineer designs the change and we build it before the flats are laid out.
Fire and sound separation in a Bermondsey conversion
Creating flats inside a house is a material change of use under the building regulations, so fire separation and sound insulation are designed in from the start. Each flat needs fire-resisting floors and walls between it and its neighbours, a protected escape route and fire doors onto the common stair. Approved Document E sets sound insulation for flats formed by material change of use at 43 dB airborne for walls, floors and stairs, and 64 dB maximum impact for floors and stairs.
In an older Bermondsey terrace the existing timber floors may not reach those figures on their own, so we add resilient ceilings, acoustic insulation and new floor layers, and Part E requires sound testing before completion. The test is booked for when the floors and ceilings are finished but before the kitchens go in, so any failure can be corrected without ripping out new work. Building control then signs off each flat on the evidence of the test and the fire strategy.
Services, addresses and neighbours on a Bermondsey conversion
Every new flat in a Bermondsey conversion needs its own services: a separate electricity supply and meter, its own heating and hot water, and a water supply that can be isolated. Drainage connects to the stack without passing through another flat's space unprotected. Supply companies need the new addresses before they will fit meters, so the owner applies to Southwark for street naming and numbering early. We programme the service connections around those lead times.
Where the conversion cuts into or builds on a party wall, the Party Wall Act applies, and the building owner serves the notices. Southwark's Householder SPD notes that a Party Wall Agreement is separate from planning permission. A Bermondsey terrace has two party walls, so beam bearings, new flues and soil pipes are planned with that in mind. The London Plan counts residential conversions as small-site intensification where they add net new homes, so the principle has support while Policy P3 protects the smaller family house.
- A consumer unit in every flat, with a registered electrician signing off each installation for Part P
- House to flat conversions into two or more self-contained units
- Pre-completion sound testing arranged before sign-off
VOA Council Tax stock of properties, March 2025, for all 6 statistical areas in Bermondsey. Counts rounded by the VOA.
The GS Renovation Difference in Bermondsey
A conversion is a sequence of separate trades that must meet one set of drawings: structure, fire separation, sound insulation, new services for each flat and the finishes. We build to the approved planning drawings and the building control approval, with a structural engineer and a registered electrician in the programme from day one. You or your designer hold the consents, and we give you a written quotation after a site visit, a written programme and the completion paperwork for each new Bermondsey flat.
- Full plans application to building control, never a building notice
- Separate meters, supplies and consumer units arranged for every flat
- Site left safe and secure at the end of every day
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FAQ
Frequently Asked Questions about Flat Conversions Bermondsey
What should I budget for a flat conversion in Bermondsey?
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 Bermondsey first, because it decides which houses can be split at all.
Can any Bermondsey house be converted into flats?
No. Southwark Plan 2022 Policy P3 does not permit a single dwelling of 130sqm or less original net internal floorspace to be sub-divided into two or more homes. Houses above that size can be considered, subject to planning permission, and the new flats must then meet the national space standards. A measured survey of the original house is the first step.
Do converted flats in Bermondsey need their own outdoor space?
Where the borough plan 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 converted terrace that can mean a garden split between the lower flats or a terrace on a rear roof, which your designer resolves at planning stage.
Should a Bermondsey conversion avoid single aspect flats?
Where the layout allows. London Plan Policy D6 says housing development should maximise dual aspect dwellings and normally avoid single aspect ones. In a terrace that can mean one flat per floor running front to back, rather than a front flat and a rear flat on each floor. That choice also simplifies the fire separation and drainage we build.
Can the flats in a Bermondsey house be turned back into one home?
Often, but planning comes first. Merging flats reduces the number of homes, which in London commonly needs planning permission, and Southwark Plan 2022 Policy P3 is titled Protection of existing homes. Your designer confirms the position before any work. The work means removing the separate kitchens, reopening the staircase to the whole house and taking out fire separation that is no longer needed. Building control approves the changes to escape routes and structure, and the suppliers merge the meters.
Is sound testing needed on a Bermondsey flat conversion?
Yes. Flats formed by a material change of use must meet Approved Document E, which sets 43 dB airborne sound insulation for walls and floors and a 64 dB maximum for impact sound through floors. Pre-completion testing shows the separating floors and walls achieve it. We build the upgraded floors and ceilings and arrange the test before the flats are finished.
Is the national space standard a building regulation?
No. GOV.UK says the Nationally Described Space Standard is not a building regulation and sits solely within the planning system. In Southwark it bites through Policy P15, which applies the standard to conversions. So the flat sizes are fixed at planning, and building control then checks fire, sound, structure and energy on the approved layout.
Does a flat conversion need party wall notices?
Often, where beams bear into a party wall, flues or soil pipes are cut into it, or new walls are built on the boundary. The building owner serves any notices under the Party Wall Act, and the adjoining owner can agree or appoint a surveyor. Southwark's Householder SPD notes that a Party Wall Agreement is separate from planning permission.
What ceiling height does a new Bermondsey flat need?
At least 2.5 metres floor to ceiling across at least 75 per cent of each flat's gross internal area, under Southwark Plan 2022 Policy P15 and London Plan Policy D6. In a terrace the rear addition and the top floor are where that is tested. The survey measures every ceiling before the layout is fixed.
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