GS Renovation carries out loft conversions in Camberwell, where SE5 mixes Georgian and Victorian townhouses with later terraces and a good deal of conservation area coverage. On a flat-fronted period house a mansard is often the only roof form Southwark will entertain, and we build to the architect's approved drawings.
Mansards on Camberwell's Georgian and Victorian townhouses
A mansard rebuilds the roof at a steep pitch with a shallow top, and it gains far more usable floor than a dormer because the walls rise close to vertical. On a Camberwell townhouse with a shallow existing roof and limited ridge height it is often the only way to get a full room rather than a crouch space. Indicative London figures for 2026 put a mansard at roughly £70,000 to £100,000 or more, which is real money and worth testing against what the house actually gains.
The trade off is planning. A mansard changes the roof profile as seen from the street, so it needs full planning permission almost everywhere in SE5, and Southwark Council will look at whether neighbouring houses in the terrace already have one. A consistent run of mansards along a street helps an application; being the first house to propose one is harder. Where the building is listed, listed building consent is required as well, and that is judged separately from the planning decision.
What the structure and the regulations demand
Rebuilding a roof is heavier work than dropping a dormer into it. Steel beams span between the party walls to carry the new floor and the mansard framing, sized by a structural engineer and bearing on padstones cut into brickwork that is often soft and lime bedded. Old water tanks come out and the house usually moves to a combi boiler or an unvented cylinder. New floor joists sit clear of the original ceiling joists, which were built to carry a ceiling and nothing more.
Fire safety then drives the internal layout. Adding a second floor to a two storey Camberwell house triggers Part B, so the stair enclosure becomes a protected route to a final exit, doors off it are fire doors and alarms are interlinked across all storeys. Part K sets the rise, going and headroom for the new stair. Because a mansard is built off the party walls on both sides, notices under the Party Wall etc. Act 1996 are effectively certain, and serving them is your duty as building owner.
- Insulation between and over rafters to Part L
- Water tank removal and conversion to a sealed system
- Building control inspections booked at floor, steel and completion
- Interlinked mains-powered smoke alarms
- L-shaped dormers over a rear closet wing
Why Camberwell Homeowners Choose GS Renovation
Camberwell roofs are constrained by heritage policy and by soft period brickwork, and both need a contractor who has handled them before. GS Renovation coordinates the architect, the engineer and the party wall surveyor, then executes the steel, the mansard and the internal fit out. Fully insured, building control compliant, free no-obligation quotations, Companies House no. 14611254.
- A dedicated project manager from first survey to handover
- Staircase set out to Part K within the space you have
- Structural engineer instructed and coordinated on your behalf
- Roof made good, leadwork and guttering finished properly
- Rated 4.9 from 31 reviews on MyBuilder
- Interlinked mains alarms fitted and certified