House Extensions in Belsize Park, NW3
Rear, side-return, wraparound and double-storey extensions for houses in Belsize Park, designed, approved and built by one team.
Covered under one contract
- Architectural and structural design
- Planning or lawful development certificate
- Foundations, walls, roof and steels
- Glazing, rooflights and doors
- Kitchen designed and fitted
- Building control and party wall handled
House Extensions in Belsize Park.
An extension is the surest way to get the open-plan kitchen and dining room most families want, and the houses in Belsize Park generally lend themselves to it: a side return to fill, a rear garden to build into, or on larger plots room for a full-width or double-storey addition.
We design the extension around how you will use it, not around the maximum footprint the rules allow. That means thinking about light, the level change to the garden, where the kitchen sits, how the old and new parts of the house meet and what happens to the rooms you already have. The structural engineering, party wall matters and building control inspections are all handled by us.
Approvals are checked on the first visit. Many single-storey rear extensions fall within permitted development, but the London Borough of Camden applies tighter rules in conservation areas and to flats and listed buildings, so we confirm the route before any drawings are produced and then manage the application if one is needed.
- Area
- Belsize Park, NW3
- Council
- London Borough of Camden
- Housing
- Italianate stucco villas and semi-detached houses of the 1850s and 1860s, mansion blocks, and houses converted into flats
- Transport
- Belsize Park, Swiss Cottage, Chalk Farm
- Rear or side return, on site
- 10 to 16 weeks
- Design and approvals
- 8 to 14 weeks before start
- Glazing lead time
- 6 to 10 weeks, ordered early
- Consent
- Permitted development or householder application
- Party wall
- Notices served by us
Belsize Park: the houses and the planning rules.
Belsize Park was laid out in the 1850s as a suburb of paired stucco villas with generous gardens, between Hampstead to the north and Primrose Hill to the south. The villas survive in long, leafy streets, many divided into flats, alongside Edwardian mansion blocks and post-war infill.
It is one of the most active refurbishment markets in north London: reuniting houses that were split into flats, refurbishing garden and first-floor maisonettes, and adding rear extensions and basements beneath the villas. Camden's Belsize guidance shapes what is possible on each street.
The Belsize Conservation Area covers most of the district.
London Borough of Camden
Camden decides applications. The Belsize Conservation Area statement sets out expectations for rear extensions, roof works and stucco repair, and Article 4 directions apply on many streets.
Flats and maisonettes
Most properties are leasehold flats, so a licence to alter from the freeholder sits alongside planning and building control.
Basements
Camden's basement policy applies, with a Basement Impact Assessment for any new lower ground floor.
Approvals for house extensions in Belsize Park.
Many single-storey rear extensions are permitted development within the 3 or 4 metre limits, or 6 and 8 metres under prior approval. Conservation areas, flats, listed buildings and larger schemes need a householder application, and every extension needs building regulations approval.
Camden decides applications. The Belsize Conservation Area statement sets out expectations for rear extensions, roof works and stucco repair, and Article 4 directions apply on many streets.
What house extensions in Belsize Park includes.
- Architectural and structural design
- Planning or lawful development certificate
- Foundations, walls, roof and steels
- Glazing, rooflights and doors
- Kitchen designed and fitted
- Building control and party wall handled
From site visit to handover.
- 01
Site visit & consultation
We visit, listen and measure. Brief, budget and constraints understood before any advice is given.
- 02
Design & itemised quote
Our architects and engineers draw the scheme, and from that we provide a transparent, itemised quotation for your approval.
- 03
Planning & approvals
Planning applications, building control and party wall matters handled for you.
- 04
Build, managed weekly
Our own trades, sequenced by a site manager. Progress reported every week.
- 05
Handover & aftercare
Joint snagging walk-through, documentation, and a guarantee on our workmanship.
House Extensions in Belsize Park: your questions.
Do I need planning permission for an extension in Belsize Park?
Not always. Permitted development covers many single-storey rear extensions on houses, but the London Borough of Camden removes those rights in some conservation areas, and flats and listed buildings always need an application. We confirm the route at the site visit.
How long does an extension take to build?
Ten to sixteen weeks on site for a single-storey extension once approvals are in place, plus the design and approval period beforehand. Glazing has the longest lead time, so we order it early.
Which parts of Belsize Park do you cover?
All of Belsize Park and NW3, including Belsize Park Gardens, Lambolle Road, Glenilla Road, Belsize Avenue, Eton Avenue, Haverstock Hill, and the neighbouring districts. We are based in London and our teams work across central, north, north-west, west and south-west London.
Other services in Belsize Park.
House Refurbishment in Belsize Park
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Flat Refurbishment in Belsize Park
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Structural Alterations in Belsize Park
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Loft Conversions in Belsize Park
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Basement Conversions in Belsize Park
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Kitchen Renovation in Belsize Park
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Bathroom Renovation in Belsize Park
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Bespoke Joinery & Fitted Furniture in Belsize Park
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Architectural & Interior Design in Belsize Park
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Planning Permission & Building Regulations in Belsize Park
Read moreHouse Extensions across London.
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We will visit, listen and explain what is possible for your property and how it would be approved. No pressure, no sales pitch.