House
extensions
in Bloomsbury, WC1
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 Bloomsbury house extensions across Gordon Square, Bedford Square, Russell Square - side-return, rear, wraparound and double-storey additions for Georgian townhouses, Bloomsbury Group terraces and larger family homes where planning strategy, conservation detailing, Party Wall sequencing and structural engineering need handling properly.
House Extensions in Bloomsbury: What You Need to Know
Every house extension project in Bloomsbury is designed to respect the Bloomsbury Conservation Area and the character of Georgian townhouses, Bloomsbury Group terraces, mansion flats. 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.
In Bloomsbury's conservation area, extensions must be designed with exceptional sensitivity. Camden 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.
Literary and academic quarter with Bedford Square, Russell Square, and British Museum. Georgian garden squares with Grade I and II listed buildings. Camden conservation area. Our extensions in Bloomsbury use materials and detailing that complement the existing architecture — whether matching traditional brickwork and stonework or introducing high-quality contemporary glazing and zinc cladding.
Bloomsbury is the great planned Georgian quarter of London, and extending a house here works within the Bloomsbury Conservation Area and largely on the Bedford Estate. Camden scrutinises external change closely and applies Article 4 controls, and the listed terraces demand careful structural and party-wall sequencing before a rear addition can proceed.
The buildings set the discipline. Bedford Square is among the most complete Georgian squares in the country; Russell Square and Gordon Square carry the Bloomsbury Group terraces; and Mecklenburgh Square and the surrounding blocks add mansion flats and academic conversions. Any new addition is designed to stay subordinate to WC1's historic elevations.
Costs are driven by restricted access, party-wall awards, structural openings in older terrace fabric, drainage, and light and overlooking constraints. On the Camden measure a single-storey rear extension is £71,250–£112,500 excluding VAT and a side return £90,000–£120,000 excluding VAT, refined once survey and consent are known.
House Extensions in Bloomsbury: Applied to the Local Stock
Bloomsbury sits in the London Borough of Camden, within the Bloomsbury Conservation Area and largely on the Bedford Estate. 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: Bloomsbury Conservation Area appraisal and management strategy page, Camden Council (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 Bloomsbury: Questions
Is Bloomsbury in a conservation area?
Yes. Bloomsbury sits within the Bloomsbury Conservation Area and largely on the Bedford Estate; Camden scrutinises external change closely and applies Article 4 controls, and the listed terraces demand careful structural and party-wall sequencing.
How are extensions handled on Bloomsbury's listed terraces?
Carefully and subordinately. New rear additions are kept subordinate to WC1's historic elevations, with party-wall awards, structural openings in older terrace fabric, drainage and overlooking all managed through the design and build.
What does a house extension cost in Bloomsbury?
In Camden a single-storey rear extension runs £71,250–£112,500 excluding VAT, a side return £90,000–£120,000 excluding VAT, and a wraparound an indicative London market band of £100,000–£200,000.
How is a kitchen extension in Bloomsbury costed?
The London-wide build rate is £2,200–£3,500 per square metre of new floor area, with a £5,000–£30,000 kitchen supply allowance on top, excluding VAT. Scope and specification then set the scheme figure.
Which Bloomsbury streets suit extensions?
Bedford Square is among the most complete Georgian squares in the country; Russell Square and Gordon Square carry the Bloomsbury Group terraces; and Mecklenburgh Square and the surrounding blocks add mansion flats and academic conversions.
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We survey your property, discuss your vision and provide a clear budget framework.