GS Renovation converts lofts across the London Borough of Lewisham, from the terraces of SE4 and SE14 to the taller Victorian houses climbing towards Forest Hill and Sydenham in SE23 and SE26. Roof sizes vary widely here, so the type that suits your house is a survey question. We coordinate the engineer and manage Lewisham Council building control.
Reading a Lewisham roof before choosing a type
The bigger Victorian houses around Telegraph Hill and Forest Hill often have steep roofs with real height to spare, and where that is the case a rooflight conversion can be genuinely worth considering. It adds no volume, keeps the roof profile as built and comes in at roughly £30,000 to £45,000 on indicative 2026 London ranges, which is a long way below a dormer. The trade-off is floor area with full standing headroom, which is always less than owners expect.
On the standard SE4 or SE13 terrace, the height is tighter and the room only works with a dormer. Measure roughly 2.2m to 2.4m from the top of the ceiling joists to the ridge as the starting point. A rear dormer costs roughly £45,000 to £65,000 and an L-shaped dormer over the closet wing roughly £55,000 to £80,000, with the L shape being what makes a separate en suite possible rather than a bedroom with a shower in the corner.
Conservation areas, structure and Lewisham Council
Lewisham Council designates a number of conservation areas, including around Blackheath and Telegraph Hill, where permitted development rights for loft conversions are removed and a planning application is needed. Outside them, the commonly cited allowance is 40 cubic metres of added volume for a terrace and 50 for a semi or detached house, with conditions on matching materials, obscure glazed side windows and nothing forward of the roof plane. We check your address before drawings are commissioned.
Structurally, the new floor is built on joists sized by the structural engineer and carried on steel beams spanning to the party walls on padstones, sitting clear of the existing ceiling joists, which were never designed to take a floor load. Lewisham building control inspects the steelwork and bearings, the fire separation and protected stair, insulation and ventilation, and issues the completion certificate at the end.
- Mansard conversions where planning will not accept a dormer
- Rooflight conversions where the roof line must not change
- Water tank removal and conversion to a sealed system
- Trussed roofs redesigned before any web is cut
- Building control inspections booked at floor, steel and completion
Why Lewisham Homeowners Choose GS Renovation
Lewisham homeowners choose GS Renovation because the borough's housing is too varied for a standard package, and we price what your roof actually allows. We coordinate the structural engineer, install steel to their design, prepare party wall notices for you to serve and take Lewisham Council building control through to a completion certificate. We are fully insured, we quote free with no obligation, and homeowners rate us 4.9 from 31 MyBuilder reviews.
- Water tank removed and the system converted where it blocks the space
- Roof type assessed so you get the scheme your house can actually take
- Straight advice on what is and is not worth spending money on
- Registered in England, Companies House no. 14611254
- Aftercare and snagging support once the job is finished
- Roof made good, leadwork and guttering finished properly