Wraparound Extension in Hampstead NW3

Why Hampstead Properties Choose Us

Victorian/Edwardian terraces, conservation area, Heath proximity. Large detached and semi-detached houses, many Grade II listed. Our team works exclusively in NW London, bringing detailed knowledge of Camden planning requirements and the specific challenges of Victorian/Edwardian terraces & detached stock. As a designated conservation area, every project in this postcode requires specialist handling — knowledge our team has built over years of delivering projects here.

Planning Authority

Camden LBC

Average Property Value

£2,800,000

Conservation Area

Yes — planning applies

Typical Project Cost

£90,000–£200,000

How a Wraparound Extension Works — Step by Step

1. 1

   Ground Floor Survey and Feasibility

   We assess the full rear and side return footprint available, mapping drainage, utilities, trees, and party wall positions. A wraparound extension is a major ground floor reconfiguration — we model the new open-plan layout and stair positions to confirm the scheme is feasible before committing to design fees.

2. 2

   Planning Application Strategy

   Wraparound extensions always require full planning permission in conservation areas and Article 4 zones — they are significant developments. We develop a planning strategy including pre-application advice, heritage impact assessment, and Design and Access Statement. In Hampstead Garden Suburb, HGS Trust consent is required alongside Barnet LBC planning.

3. 3

   Architectural Design

   The architect designs the L-shaped extension footprint, roof strategy (combinations of flat roof, lantern lights, and pitched sections), and the treatment of the rear elevation. Rooflight runs along the inner angles of the L bring daylight into the heart of the new plan. Material selection for the external envelope is driven by planning requirements.

4. 4

   Structural Engineering

   A structural engineer designs the new foundations (typically a reinforced concrete slab or strip footings), the structural steel frame for any large clear spans, and the lintels and beams for the wall openings into the existing house. Party wall and building regs calculations are prepared simultaneously.

5. 5

   Demolition, Utilities, and Groundworks

   Existing outbuildings in the rear and side are demolished. Drainage is diverted around the new footprint. Foundations are poured and inspected by building control. Any underfloor heating systems are laid into the ground floor slab at this stage — it is not possible to retrofit UFH into a solid concrete slab after the fact.

6. 6

   Superstructure Construction

   The L-shaped shell is constructed in masonry, timber frame, or structural insulated panels. The roof structure — typically a combination of flat warm roof and large pivot rooflights — is built and made weathertight. External works including drainage and landscaping connections are completed at this stage.

7. 7

   Main House Integration — Opening the Rear Wall

   With the extension weathertight, the rear wall of the existing house is opened up in one operation, inserting the structural steel frame or lintel that carries the floor above. The temporary propping is removed once the steel has cured into the masonry. The transformation of the ground floor is immediately apparent.

8. 8

   Fit-Out and Completion

   First and second fix services, kitchen, underfloor heating commissioning, plastering, tiling, and decoration are completed. Building control inspects at every key stage and issues a completion certificate. The finished product — a fully open-plan kitchen, dining, and living space spanning the full width and depth of the ground floor — is the most popular home improvement in NW London.

Wraparound Extension in Hampstead — Planning and Local Considerations

Wraparound extensions require full planning permission in Hampstead due to the Article 4 Direction and conservation area designation. Camden LBC assesses the massing of the combined rear and side infill against the conservation area character appraisal. Pre-application advice from the Camden conservation officer is essential — without it, schemes can be redesigned at significant cost during the statutory consultation period. Budget for an extended planning timeline of 10–16 weeks.

Frequently Asked Questions