GS Renovation builds loft conversions across Putney, in the Edwardian terraces climbing away from the river and the streets running towards Putney Heath. In SW15 the closet wing at the back makes an L-shaped dormer the scheme that gives a proper double bedroom and en suite. We coordinate the engineer and complete with Wandsworth Council building control.
Head height first in a Putney terrace
Before we discuss dormers or costs in an SW15 house, we measure from the top of the ceiling joists to the underside of the ridge. Roughly 2.2m to 2.4m is the working threshold. Above it, a conversion proceeds normally. Below it, the choices are lowering the ceilings in the bedrooms beneath, which means replastering those rooms and altering the stair, or raising the roof, which means a full planning application. Both are possible, but they change the budget substantially.
Where the height is there, the L-shaped dormer follows the shape of the house, running across the rear slope and turning down over the closet wing. That gives a double bedroom with full standing height, a landing that works and enough width for a shower room. Indicative London ranges in 2026 put an L-shaped dormer at roughly £55,000 to £80,000, against roughly £45,000 to £65,000 for a straight rear dormer without the wing.
Party wall and Wandsworth Council sign-off
The steel beams that carry your new floor and the dormer span between the party walls and bear on padstones cut into them. In a mid-terrace Putney house that means adjoining owners on both sides, and the work is notifiable under the Party Wall etc. Act 1996. The duty to serve notice is the building owner's, so it is yours: we are the contractor. What we provide is the structural detail your surveyor needs and a method that matches whatever is agreed.
Wandsworth Council handles building control, and the inspections cover the steels and bearings before they are enclosed, the engineer-designed floor joists, the protected stair route with fire doors and interlinked alarms, Part K stair geometry and Part L insulation. Permitted development may cover a 40 cubic metre dormer on a terrace, but parts of SW15 sit in conservation areas where those rights are removed, so we confirm the designation for your address first.
- Interlinked mains-powered smoke alarms
- Protected stair enclosure and fire doors to Part B
- Structural steel sized by the engineer and set on padstones
- Velux and conservation rooflights fitted and flashed
- Rooflight conversions where the roof line must not change
Why Putney Homeowners Choose GS Renovation
Putney homeowners choose GS Renovation because we establish feasibility with a tape measure and a straight answer before anyone spends on drawings. Then one team coordinates the engineer, sets the steels, prepares your party wall detail for both neighbours and runs Wandsworth building control to certificate. Fully insured, building control compliant, and rated 4.9 from 31 MyBuilder reviews.
- Fully insured, with cover in place on every site
- Registered in England, Companies House no. 14611254
- Staircase set out to Part K within the space you have
- A dedicated project manager from first survey to handover
- Honest answer at survey if your roof will not take a conversion
- Interlinked mains alarms fitted and certified