House
extensions
in Lancaster Gate, W2
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 Lancaster Gate house extensions across Lancaster Gate, Bayswater Road, Craven Terrace - side-return, rear, wraparound and double-storey additions for Stucco Italianate terraces, Park-Facing townhouses and larger family homes where planning strategy, conservation detailing, Party Wall sequencing and structural engineering need handling properly.
House Extensions in Lancaster Gate: What You Need to Know
Every house extension project in Lancaster Gate is designed to respect the Bayswater Conservation Area and the character of stucco Italianate terraces, park-facing townhouses, mansion flats. Our in-house RIBA Chartered Architects handle Westminster 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.
In Lancaster Gate's conservation area, extensions must be designed with exceptional sensitivity. Westminster officers assess impact on the host building, neighbouring properties, and the wider streetscape. We secure planning approval through design excellence and thorough pre-application engagement.
Prestigious Hyde Park frontage with grand Victorian terraces. Many large properties converted to flats. Westminster conservation area with heritage significance from proximity to Kensington Gardens. Our extensions in Lancaster Gate use materials and detailing that complement the existing architecture — whether matching traditional brickwork and stonework or introducing high-quality contemporary glazing and zinc cladding.
Lancaster Gate holds some of the grandest stucco in Bayswater, and its character is strongly flat-led — a fact that shapes what extending actually means here. The area lies in the City of Westminster, within the Bayswater Conservation Area, along the grand stuccoed terraces facing Kensington Gardens. Lancaster Gate itself forms a monumental set of white-fronted terraces around its gardens, so those protected elevations are kept intact and most projects work within an existing envelope.
The stock explains the constraint. Lancaster Gate is strongly flat-led, with Victorian terraces, mansion flats and period buildings where refurbishment usually has to accommodate shared structure, common parts and protected elevations. Craven Terrace and Leinster Terrace carry period houses and conversions, while the Bayswater Road frontage faces Kensington Gardens directly, so those park-facing houses are refurbished sympathetically rather than visibly extended.
Cost reflects the coordination more than plan area. A Lancaster Gate rear extension is priced at £71,250 to £112,500 before VAT, a side return near £90,000 to £120,000, with shared structure and common parts driving much of the rest.
House Extensions in Lancaster Gate: Applied to the Local Stock
Lancaster Gate sits in the City of Westminster, within the Bayswater Conservation Area, on the grand stuccoed terraces facing Kensington Gardens. London-wide cost band for rear extension — single storey: £71,250–£112,500 excluding VAT (Resi rear extension cost guide, Oct 2025).
Sources: Westminster City Council — Bayswater Conservation Area mini guide (Oct 2004) (2026); Rear extension — single storey (Resi rear extension cost guide, Oct 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 Lancaster Gate: Questions
Is Lancaster Gate mostly flats rather than houses to extend?
Largely, yes. Lancaster Gate is strongly flat-led — Victorian terraces, mansion flats and period buildings where works often have to accommodate shared structure, common parts and protected elevations. So a Lancaster Gate project is frequently reconfiguration within a leasehold envelope rather than a conventional rear extension.
How does the Bayswater Conservation Area apply at Lancaster Gate?
Lancaster Gate lies in the City of Westminster, within the Bayswater Conservation Area, along the grand stuccoed terraces facing Kensington Gardens. Lancaster Gate itself forms a monumental set of white-fronted terraces around its gardens, so those protected elevations are kept intact and external change is closely controlled.
What does an extension or reconfiguration cost in Lancaster Gate?
London-wide guidance prices a Lancaster Gate rear extension at £71,250 to £112,500 before VAT. Allow around £90,000 to £120,000 for a side return and an indicative £100,000 to £200,000 for a wraparound. Because the stock is flat-led, the shared-structure and common-parts coordination usually weighs on the figure as much as the works.
Which Lancaster Gate streets have the grand park-facing houses?
Lancaster Gate itself holds some of the grandest stucco in Bayswater — monumental white-fronted runs around its gardens. Craven Terrace and Leinster Terrace carry handsome period houses and conversions, and the streets along Bayswater Road face Kensington Gardens directly, so those park frontages are refurbished sympathetically.
What is the property stock like at Lancaster Gate?
Typical stock here is stucco Italianate terraces, park-facing townhouses and mansion flats. Its characteristic streets take in Lancaster Gate, Craven Terrace, Leinster Terrace and Bayswater Road, and getting Westminster's stucco and conservation rules right early keeps a Lancaster Gate scheme on track.
House Extensions in Nearby Areas
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We survey your property, discuss your vision and provide a clear budget framework.