House
extensions
in Dartmouth Park, NW5
Architects, Engineers, Surveyors & Builders Under One Roof.
One Studio. One Contract. One Team.
RICS surveying support for party walls, licence to alter, conservation-area works & neighbour mattersWe design and build Dartmouth Park house extensions across Dartmouth Park Hill, Dartmouth Park Avenue, Chetwynd Road - side-return, rear, wraparound and double-storey additions for Victorian terraces, Edwardian villas and Period converted houses where planning strategy, conservation detailing, Party Wall sequencing and structural engineering need handling properly.
House Extensions in Dartmouth Park: What You Need to Know
Every house extension project in Dartmouth Park is designed to respect the Dartmouth Park Conservation Area and the character of Victorian terraces, Edwardian villas, period conversions. Our in-house RIBA Chartered Architects handle Camden planning applications, our chartered structural engineers specify any load-bearing work, and our directly-employed trades deliver the build under one fixed-price contract. We coordinate Building Control, Party Wall awards where needed, and all certifications through to handover.
Dartmouth Park's conservation area status means extensions must be sensitively designed. Camden expects extensions to use matching or complementary materials and to respect the scale and character of the original building. We navigate these requirements daily.
Quiet, leafy residential area between Highgate and Kentish Town. Part of the Dartmouth Park conservation area with handsome Victorian streets and proximity to Hampstead Heath and Waterlow Park. Side-return extensions are particularly popular in Dartmouth Park's terraced streets, transforming narrow kitchen spaces into full-width open-plan living areas connected to the garden.
Local character & heritage: extending in Dartmouth Park
Dartmouth Park is a quiet, cohesive Camden village of Victorian terraces on the slopes between Hampstead Heath, Highgate and Tufnell Park, much of it within the Dartmouth Park Conservation Area and prized as a family-house area.
The stock is consistent — rows of Victorian terraced family houses — which makes the classic side-return and rear extension to open up a narrow kitchen the signature Dartmouth Park project, often paired with loft conversions to add bedrooms. Because the terraces are uniform and conservation-protected, Camden expects extensions to match the established materials and rhythm of the street.
The sloping ground toward Dartmouth Park Hill brings split-level and retaining considerations on some plots, and the tight terraced gardens mean party-wall and right-to-light matters with neighbours are routine. We plan the levels and neighbour agreements up front.
Dartmouth Park heritage & architecture: Conservation areas explained · Renovating an NW5 terrace · Listed buildings in NW5 · Dartmouth Park Hill · The building boom · Roof developments & conservation · Best family-home streets
Extending a house in Dartmouth Park is a lesson in gradient. The neighbourhood sits on the slopes between Highgate and Kentish Town, and the sloping streets around Dartmouth Park Hill, together with the Victorian party-wall layouts, shape how an extension handles garden levels and retaining as much as floor area.
The heritage controls are specific. The Dartmouth Park Conservation Area protects its steep Victorian streets and the green edge towards Hampstead Heath and Waterlow Park, and Camden states its appraisal is used when assessing applications. The Kenwood-to-St Paul's protected vista crosses the western side, so roof proposals need to address roof form, visibility and townscape.
Chetwynd Road and York Rise carry bay-fronted Victorian terraces, while the larger Edwardian villas on Dartmouth Park Hill and Dartmouth Park Avenue climb towards Highgate. Against the Camden benchmark a single-storey rear extension runs £71,250–£112,500 excluding VAT and a side return £90,000–£120,000 excluding VAT.
House Extensions in Dartmouth Park: Applied to the Local Stock
Dartmouth Park sits in the London Borough of Camden on the slopes between Highgate and Kentish Town, with the Dartmouth Park Conservation Area protecting its steep Victorian streets and the green edge towards Hampstead Heath and Waterlow Park. Dartmouth Park is a Camden conservation area and Camden states that its appraisal is used when assessing applications. Headline cost range used for a rear extension in Camden: £71,250–£112,500 excluding VAT.
Sources: Dartmouth Park Conservation Area Appraisal and Management Plan (adopted 22 January 2009), Camden Council (2026); Dartmouth Park Conservation Area appraisal and management strategy page, Camden Council (2026); Camden borough cost data (2026)
What a House Extension Involves
An extension reshapes how the whole ground floor works, not just how big it is — the new structure, the opening into the existing house, the kitchen and the garden connection all have to be designed as one move. We take each project from feasibility drawings through consents, structure and fit-out under a single fixed-price contract. Most extensions we build include the scope below.
- Rear extensions — single-storey additions that open the back of the house to the garden
- Side-return & wraparound — infilling the side alley of a terrace, alone or combined with a rear addition
- Double-storey — new bedrooms or bathrooms above the ground-floor addition, designed to sit comfortably with the original roofline
- Foundations & steel — groundworks, beams and the opening into the existing house, engineered by our own structural team
- Glazing — rooflights, glazed roofs and slim-framed sliding or bi-fold doors specified for light and thermal performance
- Kitchen integration — the kitchen layout planned with the architecture from the first drawing, not squeezed in afterwards
- Services & heating — electrics, plumbing, drainage and underfloor heating built into the new floor
- External works — patio, drainage connections and garden reinstatement completed within the contract
How We Run Your Project
Six stages, with the consents and engineering settled before the first spade goes in.
- Feasibility visit — we assess the site, the boundaries and your brief, and identify the right consent route for your property.
- Design & approvals — our architects draw the scheme while planning or permitted development paperwork, structural calculations and party wall notices progress together.
- Fixed-price contract — every element specified and priced before construction, from foundations to door hardware.
- Groundworks & shell — excavation, foundations, walls, steel and roof, taken to weathertight while you carry on living in the house.
- Fit-out — insulation, services, glazing, kitchen, flooring and decoration, with the opening into the existing house formed once the shell is sealed.
- Completion — building control inspection, snagging, external works and handover with the full certification pack.
Read the full house extension guide for extension types, permitted development limits and the build programme stage by stage.
Many rear extensions can proceed under permitted development — broadly up to 3m deep on attached houses and 4m on detached, extendable to 6m and 8m through the prior approval scheme — but conservation areas, Article 4 directions and listed status change the picture, and every extension needs Building Regulations approval regardless of the planning route. Where foundations come within 3m of a neighbouring building, the Party Wall etc. Act 1996 obliges you to give adjoining owners a minimum of two months’ written notice before construction can begin. Our planning guide library sets out the rules for each borough.
Why Hampstead Renovations
We hold £10 million public liability insurance with Aviva; the certificate is available on request.
House Extensions in Dartmouth Park: Questions
Does the hill affect an extension in Dartmouth Park?
Significantly. The gradient shapes extensions, garden levels and retaining, and the sloping streets around Dartmouth Park Hill, together with the Victorian party-wall layouts, add their own demands to the design and the build.
Are there protected views across Dartmouth Park?
There are. The Kenwood-to-St Paul's protected vista crosses the western side of the neighbourhood, so roof proposals need to address roof form, visibility and townscape, and roof and rear guidance has existed for Laurier and Boscastle Roads.
What does a house extension cost in Dartmouth Park?
Camden's single-storey rear-extension band is £71,250–£112,500 excluding VAT; a side return sits at £90,000–£120,000 excluding VAT; and a wraparound at an indicative £100,000–£200,000 on the open market.
Is Dartmouth Park a conservation area?
Yes. The Dartmouth Park Conservation Area protects its steep Victorian streets and the green edge towards Hampstead Heath and Waterlow Park, and Camden states that its appraisal is used when assessing applications.
Which Dartmouth Park streets suit extensions?
Chetwynd Road and York Rise carry bay-fronted Victorian terraces well suited to rear additions, while the larger Edwardian villas on Dartmouth Park Hill and Dartmouth Park Avenue are where the gradient most governs garden levels.
How much does a house extension cost in Dartmouth Park, NW5?
House extensions in Dartmouth Park typically cost £2,600–£4,200/sqm. A single-storey rear extension runs approximately £69,000–£115,000, while a double-storey extension costs £115,000–£207,000. Our fixed-price contracts include foundations, structural steelwork, full build and interior fit-out.
House Extensions in Dartmouth Park: Planning & Local Context
London Borough of Camden · NW5
Planning for house extensions in Dartmouth Park
Rear and side-return extensions are popular in Dartmouth Park, but permitted-development rights are frequently restricted within the Dartmouth Park Conservation Area, so most extensions need a full planning application to London Borough of Camden with design that respects the prevailing building line and materials.
London Borough of Camden & Dartmouth Park Conservation Area context
Dartmouth Park NW5 sits within the Dartmouth Park Conservation Area, and Camden enforces Article 4 directions across its conservation areas (removing many permitted-development rights) and applies its CPG basement guidance to subterranean work. Our in-house RIBA Chartered Architects prepare and submit every application to London Borough of Camden and handle pre-application discussions where early planning advice is useful.
Building Regulations
House Extensions in Dartmouth Park must satisfy Building Regulations — covering structural design to Part A, thermal performance to Part L, and drainage and foundations agreed with Building Control. Our in-house engineers manage Building Control from initial notice through to the completion certificate.
Recent work & local links
Explore our other Dartmouth Park services — Kitchen Renovation Loft Conversions — or the Dartmouth Park renovation hub for the full picture of how we work locally.
Our in-house planning team prepares and submits every London Borough of Camden application and manages building control end to end. View our planning track record →
More Services in Dartmouth Park
Book a Free Consultation
Visit our studio or invite us to survey your home. We’ll assess scope, discuss design possibilities and provide an honest budget framework — completely free.
Free Consultation
We survey your property, discuss your vision and provide a clear budget framework.