Wandsworth's family homes — the terraces between the Commons known as 'Nappy Valley' — are prime loft territory. TrustBuilt Projects builds dormer, L-shaped and mansard conversions across Wandsworth Town, the Tonsleys, Earlsfield and Balham (SW18, SW12, SW17), all managed end to end by us.
Wandsworth's appeal to growing families is exactly why loft conversions are so common here — owners want a third or fourth bedroom without leaving the area. The dominant housing is Victorian and Edwardian terraces around Wandsworth Common and the 'Toast Rack' grid, most of which suit an L-shaped dormer that turns the loft into a master suite with en-suite.
Watch for the conservation areas — the Wandsworth Common and Magdalen Park areas, plus the Heaver Estate, all carry tighter controls on anything street-facing. Rear and L-shaped dormers usually go through under permitted development, but we'll confirm your specific street's status before any work is priced.
Many Wandsworth families want the loft done alongside (or just before) a side-return kitchen extension, so the house only goes through one disruptive phase. We can sequence both, and because we manage every trade ourselves, you deal with one team and one point of contact throughout.
Loft conversion costs in Wandsworth sit close to the South London average; the main variables are roof type and whether you're adding an en-suite. Typical ranges:
| Project type | Typical cost | Timeline |
|---|---|---|
| Velux / roof-light conversion | £30,000 – £42,000 | 6–8 weeks |
| Rear dormer conversion | £45,000 – £60,000 | 8–12 weeks |
| L-shaped dormer (most common) | £55,000 – £78,000 | 10–14 weeks |
| Mansard conversion | £65,000 – £92,000 | 12–16 weeks |
Every project is quoted in writing after a free site visit — these ranges are a guide only.
Yes — this is a very common request in Wandsworth. Doing both in one programme means one set of scaffolding, one disruption period and a single team. We'll quote them together and sequence the works so the house is liveable for as much of the build as possible.
Rear and L-shaped dormers often fall under permitted development, but properties in the Wandsworth Common, Magdalen Park or Heaver Estate conservation areas face tighter rules on street-facing changes, and mansards usually need full permission. We check your address at the free site visit.
On most Wandsworth terraces, an L-shaped dormer comfortably fits a double bedroom plus en-suite by extending over the rear back addition. We measure the head height and roof structure on the visit and tell you honestly what will fit.
Most Wandsworth loft conversions take 8–14 weeks depending on type. A simple Velux conversion can be finished in 6–8 weeks; a mansard or large L-shaped dormer typically runs 12–16 weeks.
Free site visit, no obligation, written quote.
Book Your Free Visit →