House
extensions
in Barnes, SW13
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 Barnes house extensions across Barnes's principal residential streets - side-return, rear, wraparound and double-storey additions for Victorian villas, Edwardian Semis, Riverside houses and Period converted houses where planning strategy, conservation detailing, Party Wall sequencing and structural engineering need handling properly.
House Extensions in Barnes: What You Need to Know
Every house extension project in Barnes is designed to respect the Barnes Conservation Area and the character of Victorian villas, Edwardian semis, riverside houses, period conversions. Our in-house RIBA Chartered Architects handle Richmond upon Thames 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.
Barnes falls within a conservation area, which means visible external alterations require careful design and often full planning permission. Our architects have extensive experience securing approvals in Richmond's conservation areas.
Our house extension projects in Barnes are delivered by our in-house team of RIBA architects, structural engineers and specialist tradespeople. Every project is managed under a single fixed-price contract with no hidden costs.
Barnes keeps its village character within London, and an extension is designed to preserve it. The neighbourhood belongs to Richmond upon Thames, its conservation area guarding the setting around the pond and the river; the borough examines external change and enforces Article 4 controls. Church Road runs through the heart past the pond, period cottages and villas ring Barnes Green, and Glebe Road carries handsome Victorian and Edwardian family houses.
The river is the second defining factor. Castelnau brings grand Victorian villas toward the bridge, and riverside houses generally call for substantial refurbishment with attention to flood resilience. So near the Thames a rear addition is worked up with flood measures designed in from the outset, rather than bolted on, alongside the conservation-area character the village expects.
The build reflects both village and river. Rear access, party-wall awards, foundations beside older brickwork, drainage and boundary limits all shape the figure. A Barnes rear extension runs to about £71,250 to £112,500 before VAT, a side return roughly £90,000 to £120,000.
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 Barnes: Questions
How does Barnes's village conservation area affect an extension?
Barnes belongs to Richmond upon Thames, and its conservation area protects the village character around the pond and the river. The borough examines external change in its conservation areas and enforces Article 4 controls, so an addition is designed to hold that village feel — and near the water, to build in flood resilience.
Do I need to consider flooding when extending a Barnes house?
Close to the Thames, yes. SW13 work spans Victorian villas, Edwardian semis and riverside houses, and the grand Castelnau villas toward the bridge in particular call for substantial refurbishment with riverside flood resilience in mind. On those plots a rear addition is detailed with flood measures alongside the conservation-area character.
What does a house extension cost in Barnes?
London-wide guidance runs a Barnes rear extension to about £71,250 to £112,500 before VAT. A side return is dearer still, roughly £90,000 to £120,000, and a wraparound sits in an indicative £100,000 to £200,000 band. On riverside plots, flood-resilience and conservation detailing decide where a scheme lands within those figures.
What construction issues come up on Barnes houses?
A Barnes budget is shaped by rear access, party-wall awards, foundations set beside older brickwork, structural openings, drainage, tree and boundary limits, heritage-sensitive facades, and the detailing where new rooms meet Victorian or Edwardian fabric. Around Barnes Green and Church Road that conservation-led care runs through the whole build.
What kind of houses will I be extending in Barnes?
Barnes is prime family housing with a strong village feel: Victorian villas, Edwardian semis and riverside houses. Church Road runs through the middle past the pond, period cottages and villas ring Barnes Green, Glebe Road carries handsome Victorian and Edwardian family houses, and Castelnau brings grand Victorian villas toward the bridge.
House Extensions in Nearby Areas
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Free Consultation
We survey your property, discuss your vision and provide a clear budget framework.