Your local NW3 loft conversion builders
The NW3 postcode covers some of North London's most characterful streets — from the grand Victorian villas of Belsize Park to the Edwardian terraces of Swiss Cottage, the mansion flats of South Hampstead and the period cottages of Hampstead Village. Each has different roof types, different planning constraints and different conversion possibilities.
A loft conversion in NW3 typically adds £120,000–£280,000 to your property value. With our office on Finchley Road, we're the most local loft conversion builders in the postcode — we know every street, every property type, and every planning constraint.
We work closely with Camden Council's planning department and are experienced in both permitted development and full planning applications across NW3. Many streets in Belsize Park and Hampstead fall within conservation areas — we handle all the heritage sensitivity requirements.
NW3 areas we build in
The NW3 postcode covers diverse neighbourhoods, each with distinct property styles and planning rules.
Hampstead Village
Georgian and Victorian cottages, many in the conservation area. Mansard conversions popular. Planning-sensitive due to heritage character. We handle all conservation officer liaison.
Belsize Park
Large Victorian semis and terraces with excellent ridge heights. Perfect for L-shaped dormers. Many streets are conservation areas requiring sensitive design approaches.
Swiss Cottage
Mixed housing stock including 1930s semis and mansion flats. Hip-to-gable conversions work well for semis. Good access for scaffolding compared to the narrower Hampstead streets.
Primrose Hill
Compact Victorian terraces with typically good loft potential. Rear dormers under permitted development are the most common conversion type here.
South Hampstead
Edwardian and Victorian terraces with varied roof forms. Many properties suit standard rear dormers. Quick access from our Finchley Road office.
Chalk Farm
Victorian terraces and converted properties. Good ridge heights for dormer or mansard conversions. Close to Camden Town conservation area boundaries.
"Ross and team completely transformed our loft into a stunning master suite with en-suite and walk-in wardrobe. The attention to detail was exceptional — from the bespoke eaves storage to the Juliet balcony. Finished on time and exactly on budget."Cirus RehmanHomeowner, Hampstead NW3
Loft conversion costs in Hampstead
Realistic price ranges specific to Hampstead properties. We provide a fixed price after surveying your loft — these are guides based on recent local projects.
| Loft Conversion Type | Typical Range (Hampstead) |
|---|---|
| Rear dormer (standard spec) | £48,000 – £65,000 |
| Rear dormer (premium spec) | £65,000 – £90,000 |
| Mansard conversion | £58,000 – £95,000 |
| Hip-to-gable + rear dormer | £55,000 – £80,000 |
| L-shaped dormer | £65,000 – £100,000 |
| Velux / rooflight only | £32,000 – £48,000 |
| En-suite bathroom | Included in price |
| Bespoke eaves storage | £1,500 – £4,000 |
All prices exclude VAT. Includes structural steelwork, staircase, fire compliance, electrics, plumbing, insulation, plastering, decoration and Building Control sign-off. Prices reflect Hampstead-area build costs as of 2026.
Loft conversion FAQ — NW3
We cover the entire NW3 postcode: Hampstead, Belsize Park, Swiss Cottage, Primrose Hill, Chalk Farm, South Hampstead, Frognal, and all surrounding streets. Our office is on Finchley Road, NW3 — we are genuinely local.
Most NW3 Victorian terraces suit a rear dormer (under permitted development) or an L-shaped dormer for maximum space. Properties in conservation areas may need a mansard. We assess your specific property during the free survey.
Rear dormers typically fall under Permitted Development. However, many NW3 streets are in conservation areas where PD rights may be restricted. Mansards always need planning. We check your specific address and handle all applications.
A rear dormer in NW3 typically costs £48,000–£65,000 standard spec, or £65,000–£90,000 premium. Mansards run £58,000–£95,000. L-shaped dormers £65,000–£100,000. All include en-suite, staircase, structural work and Building Control.
Typically 8–12 weeks on site for a dormer, 10–14 weeks for a mansard. Add 4–8 weeks beforehand for design, engineering and party wall. Conservation area planning adds another 8 weeks if applicable.
Yes — almost all our NW3 clients stay in the house throughout. Work is concentrated in the loft and roof area. The noisiest period is weeks 1–2 (scaffolding, roof strip, steelwork). The staircase installation affects the floor below for 3–4 days.
Book a free loft survey in NW3
We'll visit your NW3 property, measure the loft, check head height and roof structure, assess conservation area and permitted development eligibility, and give you a realistic price — completely free, no obligation.
Unit 3, Palace Court, 250 Finchley Road, Hampstead, London NW3 6DN
Mon–Fri 9am–8pm · Saturday 9am–6pm · Sunday by appointment
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