Architects, Engineers, Surveyors & Builders Under One Roof.
Surveyor-led refurbishment advice via Hampstead Chartered Surveyors →One Studio. One Contract. One Team.
We deliver Primrose Hill building projects with an integrated design-build team under one fixed-price contract - RIBA design, structural engineering, party wall coordination, procurement, directly managed site teams, Building Control, programme control and final handover through one accountable fixed-price contract.
Our studio sits at Unit 3, Palace Court, 250 Finchley Road, NW3 6DN, and our team regularly works across Primrose Hill NW1. Building in Primrose Hill means understanding the exact address, building type, access constraints, conservation setting and freeholder requirements before pricing the works. We keep design, planning, structural engineering and site delivery under one accountable team, so the build is planned around the property rather than patched together late.
Unlike many firms calling themselves "builders in Primrose Hill" — who are essentially contractors subcontracting design, planning and structural work to third parties — we are an integrated design-build practice. Our RIBA chartered architects, RICS regulated surveyors, IStructE chartered engineers and FMB-registered site teams are all directly employed, not bought in per project. That means a single contract, a single insurer, a single point of responsibility, and no finger-pointing between separate firms when a detail needs resolving on site.
Primrose Hill projects can involve Regency and Victorian terraces, villas, converted houses and mansion flats around Regent's Park Road, Chalcot Square, Gloucester Avenue and the park edge. That demands methodology beyond a generic building quote: matching materials where period fabric is retained, planning structure around occupied neighbours, coordinating access and deliveries, and checking conservation, listing, Article 4, lease or freeholder controls where they apply. We resolve those constraints before site work starts, not as surprises during the build.
Camden · NW1
Conservation-area status, Article 4 directions, listing, lease or freeholder rules and local authority requirements all need checking against the exact address. Some Primrose Hill properties can use standard routes; others need fuller planning or heritage documentation before windows, roof works, external plant, lightwells or extensions are agreed. We check the route before drawings are fixed.
Conservation officers and freeholder teams, where relevant, expect external materials to suit the building and street. On period fabric this can mean matching brick, stucco, stone, slate, timber windows or metalwork rather than specifying generic modern replacements. We build those constraints into the scope before ordering joinery, facade repairs or roof finishes.
Primrose Hill's terraces, villas, converted houses and mansion flats can bring Party Wall Act, access, noise, working-hours and protection requirements into the programme. Our in-house RICS surveyors identify notices, schedules of condition, scaffolding, common-parts protection and delivery constraints early so the build does not stall after strip-out.
Every Primrose Hill build we deliver carries NHBC or ABC+ 10-year structural warranty and Building Regulations sign-off against current Parts A through P. Where conservation-area, listing, lease or freeholder controls apply, we prepare the supporting documentation and coordinate statutory approvals so planning, Building Regulations and any private consent route are aligned before work starts.
Our in-house planning team prepares address-specific planning and Building Regulations packs for Primrose Hill projects. View our planning track record →
Camden · NW1
One practice, every discipline, one fixed price — from feasibility drawing to final handover photograph. Our RIBA architects design, our IStructE engineers calculate, our RICS surveyors handle party wall and scope, and our FMB-registered site teams deliver the build. Heritage restoration, house extensions, loft and basement conversions, full refurbishments — across Hampstead and the wider NW1.
Primrose Hill projects can involve Regency and Victorian terraces, villas, converted houses and mansion flats around Regent's Park Road, Chalcot Square, Gloucester Avenue and the park edge. Each property carries different constraints and opportunities, and the right building route depends on the exact address, conservation area, listing status, lease or freeholder controls and scope.
We are the design-build practice built for this. One integrated team — RIBA chartered architects, IStructE chartered engineers, RICS regulated surveyors, FMB-registered site teams — operating under one contract with one fixed price. For a typical client, the alternative is appointing four to six separate firms (architect, engineer, planning consultant, party wall surveyor, main contractor, heritage consultant), each with their own fee, their own insurer, their own schedule and their own commercial interest. That structure is where many build projects lose time and cost control.
Our scope covers NW1 work: heritage restoration of listed and conservation-area fabric, rear and side-return house extensions, loft conversions, basement conversions and dig-downs, and full refurbishments of Georgian, Victorian, Edwardian and post-war properties. We coordinate with the relevant planning, conservation and building control teams where applicable, and keep party wall, freeholder, access and site-logistics requirements aligned before work starts.
Every project starts with a free on-site feasibility review. We visit your property, assess the fabric, identify the planning route (full application, Listed Building Consent, prior approval or permitted development), check Article 4 designations for the address, flag Party Wall Act implications, and provide honest, written scope and indicative figures — before any design fees are committed.
Four core disciplines for Primrose Hill NW1 properties — each priced by scope, delivered by the same integrated team, and linked below to the full service page with detailed scope and case studies.
Conservation-area and listed-building work across Primrose Hill — fabric repair, sash window restoration, cornice and metalwork repair, matched brick, stone or stucco where required. Handled with Listed Building Consent and heritage statements where applicable.
Rear, side-return, wraparound and double-storey extensions for Primrose Hill properties where the site and planning context allow. Kitchen-led open-plan designs with structural glazing, conservation-aware materials and planning managed in-house where required.
Vertical expansion: dormer, mansard and roof conversions where the roof form, conservation context and neighbour impact allow, plus cellar conversions and basement works with waterproofing and structural design by our IStructE engineers.
Whole-house strip-out and reconfiguration — structural reordering, new services, full finishes, bespoke kitchens and bathrooms, smart home and AV. For Primrose Hill properties being brought into contemporary use without losing period character.
In Primrose Hill, the planning route depends on the exact address, conservation area, listing status, Article 4 position, lease or freeholder rules and scope. Here is the real-world approvals journey for a typical NW1 build, handled end-to-end by our in-house team.
Step 1 — Pre-application consultation where useful: For any scheme where officer judgement matters (materials, massing, heritage impact, listed fabric or neighbour impact), we consider pre-application advice with the relevant local planning authority before the main submission. The written response can de-risk the full drawing set and flag amendments before technical design is fixed.
Step 2 — Householder planning application (or Listed Building Consent): The main submission. We prepare the drawing pack, Design & Access Statement, Heritage Statement where required, CIL information and ownership certificates. The statutory route depends on Camden, depending on the exact address and scope. Where the property is listed, Listed Building Consent runs in parallel and is submitted as a bundled application where appropriate.
Step 3 — Neighbour notification and consultation: The local authority may post site notices and consult adjoining owners. We draft proactive letters to neighbours before submission in complex cases, especially where access, scaffolding, noise or shared walls need to be understood before the formal consultation starts.
Step 4 — Decision at 8 weeks: Most householder applications are decided under delegated authority by the case officer. Where a scheme is contentious, listed or heavily objected to, committee routes or additional information requests can follow. Our early design and planning work is intended to reduce that risk where possible.
Step 5 — Building Regulations application: A separate consent regime from planning. Submitted to the relevant building control body or an approved inspector alongside structural calculations, SAP / Part L energy calculations, drainage strategy and fire safety design. Full Plans approval is issued before work starts.
Step 6 — Party Wall Act notices: Served at least 2 months before works commence, under sections 1, 2 and 6 of the Party Wall etc. Act 1996. In terraces, villas, converted houses and mansion flats our in-house RICS surveyors identify affected adjoining owners early and prepare notices, schedules of condition and awards where required.
Step 7 — Build: CDM 2015 role appointed (Principal Designer and Principal Contractor both held by us on design-build schemes), site set-up, hoarding, programme confirmed with neighbours, and the build proceeds on a fixed contract.
In Primrose Hill, neighbour management can be as sensitive as the build itself, especially in terraces, villas, converted houses and mansion flats. We treat it as part of the technical brief.
On Primrose Hill projects, extensions, steel openings, basement works or roof alterations can trigger sections 1, 2 and 6 of the Party Wall etc. Act 1996. Foundations within 3m (or 6m where deeper than the neighbour's) of an adjoining wall, cutting into a party wall, or raising a party wall may require notice before works start. Our in-house RICS surveyors draft and serve notices and coordinate awards where required.
Amenity impact is assessed through planning, but the common law right to light is a separate legal matter. For roof additions, rear extensions, basement lightwells or works beside principal habitable rooms, we commission daylight/sunlight advice where the risk warrants it and align the design before the formal application is submitted.
We write to adjoining owners and leaseholders before formal consultation where useful, explaining the scheme with a concise plan pack, answering obvious concerns, and proposing a realistic build programme. On sensitive streets this reduces avoidable objections and keeps practical issues away from the critical path.
Under CDM 2015 we hold both Principal Designer and Principal Contractor duties on our design-build schemes. On constrained Primrose Hill streets this means scaffold licences, parking or loading constraints, deliveries, dust control and neighbour communication are planned in advance with the relevant local authority or building manager where required.
A separate consent regime from planning. Every build we complete carries full Building Regulations sign-off and a 10-year structural warranty. Here are the Parts that matter most in Primrose Hill.
The most impactful regulation for refurbishments and extensions. New walls, roofs, floors and glazing must meet current thermal standards, while listed fabric and sensitive period elements can require a carefully justified approach. SAP calculations are prepared in-house.
Builds close to boundaries can require fire-resistant external walls and controlled openings. Loft conversions require protected means of escape, fire doors and mains-linked alarms. We design fire strategy alongside structure and heritage detailing rather than treating it as a late compliance exercise.
Party walls, flats and converted houses need proper acoustic planning. Any new wall or floor between dwellings, or work forming a new room against shared structure, may need Part E design and testing. We coordinate floor build-ups, ceilings and service penetrations before finishes are ordered.
Part M can affect thresholds, door widths and circulation, especially where period plans are tight. Part P electrical safety is certified by our in-house NICEIC-registered electrician, with test results bundled into handover documentation.
Warranty and insurance: Every build we deliver is covered by a 10-year structural warranty (NHBC or ABC+), £10M professional indemnity and £10M public liability, with all risks contract works insurance in place from site set-up to handover. Building Control sign-off is a condition of final invoice — we do not invoice the retention until the completion certificate is issued.
A clear, structured process that takes the uncertainty out of extending your home.
We visit your property, measure the site, assess the garden, check party wall situations and discuss your brief in detail. We identify whether your extension falls within permitted development rights or requires planning permission, and flag any conservation area, Article 4 or tree preservation order constraints. You receive a written feasibility assessment with an indicative budget and recommended approach within 48 hours.
Our architects produce the extension layout with 3D visualisations. Structural engineers design the steelwork, foundations and connection details. We submit planning applications or lawful development certificates, building regulations packages and party wall notices in parallel. For design-and-build projects, the kitchen design, lighting scheme and material selections run concurrently so everything is resolved before construction starts.
Foundations are excavated and poured (typically strip or trench-fill), walls built to DPC level, floor slab laid and the structural shell erected — blockwork walls, steel beams, lintels and the roof structure. The opening between the existing house and the new extension is formed, with temporary propping supporting the existing structure until the steel beam is in position. Once the roof is weathertight, the extension is sealed and internal works begin.
Insulation, plasterboarding, first fix electrics and plumbing, underfloor heating, window and door installation, kitchen fit-out, tiling, flooring, second fix carpentry, painting and decoration. Bi-fold or sliding doors are installed connecting the extension to the garden. External works — patio, drainage, landscaping — complete the project. Building control conducts the final inspection and issues the completion certificate.
Guide prices for London house extensions. All prices are fixed and include design, engineering, planning, full build and decoration.
Infilling the side alley with a glazed roof. Doubles kitchen width and creates a bright, open-plan ground floor. 8–15 sqm added.
Full-width or partial rear extension with bi-fold doors to the garden. Creates a generous kitchen-diner-living space. 15–30 sqm added.
Combined rear and side extension creating an L-shaped addition. The largest single-storey extension option. 25–45 sqm added.
Two-storey extension — kitchen below, bedroom or bathroom above. Best sqm/cost ratio but requires full planning permission. 30–60 sqm total.
What separates a Hampstead Renovations build from a standard builder's quote.
Every extension is designed by a RIBA architect to suit your specific house, site and lifestyle. No templates, no catalogue layouts — a bespoke design that maximises light, space and the connection between your home and garden.
Architects, structural engineers, planning consultants, party wall surveyors and build teams all under one roof. No subcontracted design, no outsourced engineering, no coordination gaps between separate firms. One team, one contract, one accountable party.
The price we quote is the price you pay. Not an estimate with provisional sums. Not a price that escalates when you choose your fixtures. A fixed, agreed total covering design, engineering, the full build and every material specified in the contract.
We've secured planning approvals across every inner London borough — including conservation areas in Camden, Islington, Westminster and Haringey with the most restrictive policies.
We maximise what can be achieved under PD rights — including the larger home extension scheme (up to 6m rear on terraces, 8m on detached) — avoiding planning costs and delays where possible.
Structural glass roofs, frameless glass corners, slim-profile aluminium bi-folds and floor-to-ceiling fixed glass. We design extensions that flood the ground floor with natural light.
Most extensions are kitchen-led. Our kitchen designers work alongside the architect from day one, ensuring the kitchen layout, island position and appliance locations drive the extension geometry — not the other way round.
RICS surveyors handle all party wall notices and agreements in-house. For terraced and semi-detached extensions, party walls are always a factor — our experience streamlines the process.
We install wet or electric underfloor heating beneath extension floors as standard on most projects — eliminating radiators and freeing up wall space in the new room.
In sensitive settings, we design extensions that satisfy conservation officers — using appropriate materials, roof forms and detailing that complement the existing building's character.
Patio, drainage, garden reinstatement and boundary work are part of the fixed-price contract — not treated as extras that inflate the final bill after the extension is built.
Selected house extensions completed by our team across London.
6m full-width rear extension with structural glass roof and 4m bi-fold doors. Open-plan kitchen-diner with island under permitted development.
L-shaped wraparound creating 38sqm open-plan kitchen-diner with glazed side return and full-width rear doors. Planning approved in conservation area.
Two-storey rear extension — open-plan kitchen below, master bedroom with en-suite above. Full planning permission secured through Haringey.
Need a same-day repair or maintenance visit in NW London?
Visit Hampstead On Demand →The side-return extension completely transformed our ground floor. What was a dark, narrow kitchen is now a bright, open-plan room with a huge skylight running the full length. The architect suggested the glazed corner detail that everyone comments on — that's the difference between a design-and-build firm and a standard builder's extension.
We were worried about getting planning for a wraparound in a conservation area. Hampstead Renovations designed an extension with zinc cladding and a recessed glass link that the conservation officer praised as exemplary. The build was immaculate and the fixed price held exactly — not a single extra charge in 14 weeks of construction.
Having the kitchen designer, architect and structural engineer all working together from the start meant our extension was designed around our kitchen — not the other way round. The island position, the sink location, the pendant lighting — everything was resolved before the builders dug the foundations. No compromises, no changes on site.
Everything London homeowners ask about house extensions.
Use these area-specific guide pages to compare the next build routes, planning questions and cost topics people commonly research in Hampstead NW3.
We visit your property, assess the site, discuss your brief and give you an honest feasibility assessment — including extension type, budget, timeline and planning route. No obligation.
We visit your property, measure the site and provide a clear assessment of what's achievable — completely free.
Book Free ConsultationWe're not a national chain — we're a local design and build practice serving Primrose Hill and the surrounding neighbourhoods from our Finchley Road studio.
Our design studio at 250 Finchley Road NW3 is open for design meetings, material reviews and project scoping before work starts.
Our RIBA architects coordinate with the relevant planning department, conservation officers and building control team where required. We check the route against the exact address before drawings are fixed.
From Regency and Victorian terraces, villas, converted houses and mansion flats around Regent's Park Road, Chalcot Square, Gloucester Avenue and the park edge — we understand the specific construction challenges and planning context of Primrose Hill property types.
Our NW3 studio serves the wider catchment. Adjacent North London builders pages: