GS Renovation converts lofts across the London Borough of Merton, from the Victorian villas near Wimbledon Common in SW19 to the Edwardian terraces of CR4 and the suburban houses around Morden Hall Park in SM4. Villas and terraces need different conversions, so the survey comes before the design. We coordinate the engineer and manage Merton Council building control.
Villas, terraces and the volume you have left
Merton is one of the boroughs where the permitted development volume allowance genuinely matters, because so many houses here have already been extended. The commonly cited figures are 40 cubic metres of added roof volume for a terrace and 50 for a semi or detached house, but any previous dormer, rear addition at roof level or earlier conversion counts against that total. A large loft designed without checking what has already been used is how projects end up in a retrospective planning application.
On a detached or semi-detached villa in SW19 or SW20, a hip to gable with a rear dormer behind it usually gives the best result, at roughly £55,000 to £80,000 on indicative London ranges for 2026. On an Edwardian terrace in CR4 with a rear closet wing, an L-shaped dormer covers similar ground. Either way the ridge needs roughly 2.2m to 2.4m of height above the existing ceiling joists to work without lowering ceilings below.
Conservation areas and Merton Council consents
Merton Council designates conservation areas including around Wimbledon Village and the streets near the All England Club, and within them permitted development rights for loft conversions are removed entirely. Article 4 directions can have the same effect elsewhere. Where a planning application is needed, the design is judged on how the new roof form reads from the street and from neighbouring gardens, which usually favours a subtler dormer or a mansard over a full width box.
Building regulations apply on every job regardless of the planning route. Merton building control will inspect the steel beams and their padstone bearings, the engineer-sized floor joists sitting clear of the old ceiling joists, the protected stair route with fire doors and interlinked alarms, the stair geometry, and the insulation and ventilation. We build to the engineer's design and hand over the completion certificate at the end, which matters when you sell.
- Insulation between and over rafters to Part L
- Ventilation paths kept clear at eaves and ridge
- Rooflight conversions where the roof line must not change
- Staircase design to Part K, including the landing below
- Head height and ridge survey before design
Why Choose GS Renovation in Merton
Merton homeowners choose GS Renovation because we check what volume and consents your house has already used before promising anything, then build the loft as one coordinated job. Structural engineer, steelwork, party wall paperwork, Merton Council building control, stair, en suite and decoration, all under one project manager. Fully insured, free no-obligation quotations, and 30+ years of hands-on experience behind the founder.
- Water tank removed and the system converted where it blocks the space
- Waste cleared as we go, not left piled in the garden
- Protected stair route and fire doors detailed to Part B
- Paperwork and certificates handed over for when you sell
- Honest updates if a date or a detail has to move
- Free, no-obligation quotations