House
extensions
in Hammersmith, W6
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 Hammersmith house extensions across Hammersmith's principal residential streets - side-return, rear, wraparound and double-storey additions for Riverside Georgian terraces, Victorian villas and larger family homes where planning strategy, conservation detailing, Party Wall sequencing and structural engineering need handling properly.
House Extensions in Hammersmith: What You Need to Know
Every house extension project in Hammersmith is designed to respect the Hammersmith Conservation Area and the character of riverside Georgian terraces, Victorian villas, Edwardian mansion flats. Our in-house RIBA Chartered Architects handle Hammersmith & Fulham 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.
Hammersmith has conservation area coverage in parts, so some properties will need planning permission for external changes while others may proceed under permitted development. We assess each property individually.
Our house extension projects in Hammersmith 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.
Extending a house in Hammersmith works across two very different grains. Conservation areas protect Brook Green and the historic riverside terraces, and Hammersmith and Fulham scrutinises external change while applying Article 4 controls, so the consent route depends on which part of W6 your house sits in.
The stock ranges from riverside heritage to family villas. Hammersmith Terrace and Black Lion Lane carry fine Georgian riverside houses; Brook Green brings handsome Victorian villas and family terraces well suited to whole-house work, lofts and rear extensions; and Glenthorne Road and the surrounding streets add Edwardian mansion flats and conversions.
Busy central-W6 logistics around King Street then shape delivery. As headline figures a single-storey rear extension is £71,250–£112,500 excluding VAT and a side return £90,000–£120,000 excluding VAT, with a wraparound at an indicative market band of £100,000–£200,000; a survey narrows those to your house.
House Extensions in Hammersmith: Applied to the Local Stock
Hammersmith sits in the London Borough of Hammersmith and Fulham, with conservation areas protecting Brook Green and the historic riverside terraces. Hammersmith and Fulham scrutinises external change in its conservation areas and applies Article 4 controls. London-wide indicative market band for wraparound extension: £100,000–£200,000 (source VAT treatment unstated, shown as an indicative market band, not a normalised ex-VAT figure) (Resi wraparound extension guide, 2025).
Sources: LBHF — Conservation areas (borough list of 44 conservation areas) (2026); LBHF — Article 4 Directions (planning policy page) (2026); Wraparound extension (Resi wraparound extension guide, 2025) (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 Hammersmith: Questions
What is distinctive about extending in Hammersmith?
Its split character. Conservation areas protect Brook Green and the historic riverside terraces, and Hammersmith and Fulham scrutinises external change while applying Article 4 controls, so the consent route depends on which part of W6 your house sits in.
Which Hammersmith houses suit extensions?
The handsome Victorian villas and family terraces around Brook Green are ideal for whole-house refurbishment, lofts and rear extensions, while the fine Georgian riverside houses on Hammersmith Terrace and Black Lion Lane call for a more conservation-led hand.
What does a house extension cost in Hammersmith?
As headline ranges excluding VAT, a single-storey rear extension runs £71,250–£112,500 and a side return £90,000–£120,000, while a wraparound carries an indicative market band of £100,000–£200,000.
How is a kitchen extension in Hammersmith priced?
A London-wide build rate of £2,200–£3,500 per square metre of new floor area applies, plus a £5,000–£30,000 kitchen supply allowance, excluding VAT. Scope and specification then set the scheme figure.
Which Hammersmith streets do you work on?
Hammersmith Terrace and Black Lion Lane by the river, Brook Green and Glenthorne Road for the Victorian villas and Edwardian mansion flats, and the streets tied to King Street.
House Extensions in Nearby Areas
More Services in Hammersmith
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Free Consultation
We survey your property, discuss your vision and provide a clear budget framework.