Architects, Engineers, Surveyors & Builders Under One Roof.
Surveyor-led refurbishment advice via Hampstead Chartered Surveyors →One Studio. One Contract. One Team.
We deliver Highgate 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 — a short journey across the heath to Highgate Village, Dartmouth Park and Hampstead Lane. Operating a builder in Highgate from Portsmouth or Essex is a fundamentally different proposition to operating one where the team knows every conservation sub-area, every Camden, Haringey and Islington case officer, and every reclamation yard that supplies the right London stock brick. We are local, permanent and accountable on the same network of streets as our projects.
Unlike most firms calling themselves "builders in Highgate" — who are essentially sole-trader 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.
Highgate's built fabric — Georgian terraces around Pond Square and South Grove, Victorian villas on Highgate West Hill and Bisham Gardens, Edwardian terraces along Shepherd's Hill and Stanhope Road, and the listed houses lining The Grove and Hampstead Lane — demands methodology that a general builder is not equipped for. We work daily with lime mortar rather than cement, match reclaimed London stock brick rather than standard commons, commission period-correct sash windows with 20mm astragals rather than off-the-shelf replacements, and retain specialist sub-trades for sash window restoration, lime plastering, cornice moulding and cast-iron repair. The Highgate Conservation Area — which straddles Camden, Haringey and Islington — and the Article 4 directions issued separately by each council are not obstacles we learn on your project; they are the policy environment we work in every week.
Camden / Haringey / Islington · N6
Large portions of Highgate sit under Article 4 directions issued separately by Camden, Haringey and Islington — each removing permitted development rights that homeowners elsewhere take for granted, including cladding, window replacement, front porches, roof alterations and most front-facing external changes, all of which now require a full householder application. Within the Highgate Conservation Area itself, the Article 4 regime is materially more restrictive than standard borough policy, and a quick "just-swap-the-windows" project often becomes a planning submission with heritage statement attached. We check Article 4 status for every N6 postcode and confirm which council determines it at feasibility stage, before any drawings are commissioned.
Camden, Haringey and Islington's conservation teams will reject schemes that specify standard modern materials in Highgate. Brickwork must be London stock, laid in NHL lime mortar with a flush weatherstruck joint — not cement. Windows must be timber sash with slim 20mm astragals and historically appropriate glazing bar arrangements. Roofs must be natural slate or clay tile, never concrete. We hold long-standing accounts with reclamation yards for stock brick and commission joinery from workshops that make period-accurate sashes, casements and door frames to drawing — not from catalogues.
Highgate's tightly-packed Victorian terraces and joined mansion flats mean almost every build in N6 triggers Party Wall Act 1996 notifications — sections 1, 2 and 6 in most cases, and increasingly serial section 6 notices to adjoining owners above and below when working in the lower ground. Our in-house RICS surveyors draft notices, conduct schedules of condition and negotiate the award without going to the additional expense of instructing a third-party surveyor. On congested streets like Bisham Gardens or Cromwell Avenue, this alone can save four to eight weeks of pre-construction time.
Every Highgate build we deliver carries NHBC or ABC+ 10-year structural warranty, full Building Control sign-off (with Camden, Haringey or Islington — depending on which side of the borough boundary the property sits) against current Parts A through P, and where the property is in the Highgate Conservation Area (or listed) we prepare the heritage statement and Design & Access Statement required by the relevant council's validation checklist. Listed Building Consent is a separate consent regime from planning — our applications bundle both where applicable, avoiding the common trap of receiving planning approval but being unable to lawfully start work.
Our in-house planning team has a 97% approval rate across Camden, Haringey and Islington. View our planning track record →
Camden / Haringey / Islington · N6
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 Highgate and the wider N6.
Highgate's housing stock is some of the most architecturally significant in London. Georgian terraces around Pond Square and South Grove, stucco Victorian villas along Highgate West Hill and Fitzroy Park, red-brick Edwardian mansion blocks around Highgate High Street, and rare listed Arts & Crafts cottages tucked off The Grove — each property carries constraints and opportunities that a general building contractor is not equipped to navigate. The same house that earns a premium on The Grove also comes with conservation scrutiny — split across Camden, Haringey and Islington — and Article 4 restrictions that remove most permitted development rights.
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 the majority of Highgate build projects lose time and cost control.
Our scope covers the full spectrum of N6 work: heritage restoration of listed and conservation-area fabric, rear and side-return house extensions, loft conversions (dormer, mansard and hip-to-gable, all sensitive to Highgate roofscape policy), basement conversions and dig-downs, and full refurbishments of Georgian, Victorian, Edwardian and post-war properties. We work daily with the planning, conservation and building control teams at Camden, Haringey and Islington — and have a 97% first-submission approval rate across N6.
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 Highgate N6 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 Highgate — lime mortar repointing, sash window restoration, cornice and cast-iron repair, matched reclaimed brick. Handled with Listed Building Consent and heritage statements where required.
Rear, side-return, wraparound and double-storey extensions for Highgate's Victorian and Edwardian terraces. Kitchen-led open-plan designs with structural glazing, conservation-area-compliant materials and Camden / Haringey / Islington planning managed in-house.
Vertical expansion: dormer, mansard and hip-to-gable loft conversions sensitive to Highgate's roofscape policies, plus cellar conversions and basement dig-downs with full waterproofing and underpinning 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 Highgate properties being brought into contemporary use without losing period character.
In Highgate, permitted development is rarely available — conservation area designation and Article 4 directions see to that, and the Highgate Conservation Area itself spans Camden, Haringey and Islington. Here is the real-world planning journey for a typical N6 build, handled end-to-end by our in-house team.
Step 1 — Pre-application consultation: For any scheme where officer judgement matters (materials, massing, heritage impact, listed fabric), we submit a paid pre-application to the relevant council — Camden, Haringey or Islington, depending on which side of the borough boundary your property sits — and meet the allocated conservation or design officer on site or at their offices. Typical turnaround is 4–6 weeks. The officer's written response de-risks the main submission and flags any amendments required before we invest in the full drawing set.
Step 2 — Householder planning application (or Listed Building Consent): The main submission. We prepare the drawing pack, the Design & Access Statement, the Heritage Statement (mandatory in the Highgate Conservation Area), CIL information and ownership certificates. The statutory determination period at Camden, Haringey and Islington is 8 weeks from validation. Our N6 first-submission approval rate is 97%. Where the property is listed, Listed Building Consent runs in parallel and is submitted as a bundled application.
Step 3 — Neighbour notification and consultation: The relevant council posts site notices and writes to adjoining owners with a 21-day consultation period. We draft proactive letters to neighbours before submission in complex cases — a short pre-emptive conversation on Bisham Gardens or Cromwell Avenue is often worth the entire planning fee.
Step 4 — Decision at 8 weeks: Most Highgate householder applications are decided under delegated authority by the case officer. Where a scheme is contentious — nearly always a listed building or a high-volume objection case — it goes to the relevant Planning Committee at Camden, Haringey or Islington. Our pre-app work is designed to avoid committee wherever possible.
Step 5 — Building Regulations application: A separate consent regime from planning. Submitted to the relevant council's Building Control — Camden, Haringey or Islington — (or to 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 tightly-packed Highgate terraces our in-house RICS surveyors typically need to serve on 4–8 neighbouring owners per project.
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 Highgate's tightly-packed terraces and mansion blocks, the neighbour dimension is often more sensitive than the build itself. We treat it that way.
On Highgate's Victorian terraces — Bisham Gardens, Cromwell Avenue, Stanhope Road — virtually every build triggers 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 all require notice at least 2 months before works start. Our in-house RICS surveyors draft and serve notices, and negotiate the award, without the additional cost of a third-party surveyor — included in our contract.
The relevant council assesses amenity impact under the planning system, but the common law right to light is a separate legal matter — a neighbour can seek an injunction even after planning approval if light is substantially reduced. For mansard lofts, rear extensions over 3m deep, and any work adjoining a neighbour's principal habitable rooms, we commission BRE daylight/sunlight assessments in advance. On one recent Cholmeley Park N6 project this pre-empted an objection and closed the issue before formal council consultation began.
We write to adjoining owners and leaseholders before formal council consultation, explaining the scheme with an A3 plan pack, answering obvious concerns, and proposing a realistic build programme. On contentious streets this materially reduces the volume and character of objections submitted during the council's 21-day consultation — and turns neighbours who would have emailed the case officer into neighbours who stay quiet or write in support.
Under CDM 2015 we hold both Principal Designer and Principal Contractor duties on our design-build schemes. On narrow Highgate streets this means scaffold licences and skip permits agreed with the relevant Highways team — Camden, Haringey or Islington — in advance, deliveries scheduled outside school drop-off, dust suppression on any brick-cutting, and a named site manager reachable by neighbours throughout the programme. It is the difference between a build the street tolerates and one the street complains about weekly.
A separate consent regime from planning. Every build we complete carries full Building Regs sign-off and a 10-year structural warranty. Here are the Parts that matter most in Highgate.
The most impactful regulation for Highgate refurbishments and extensions. New walls, roofs, floors and glazing must achieve minimum U-values: walls 0.18–0.28 W/m2K, flat roofs 0.18 W/m2K, floors 0.22 W/m2K, windows 1.4–1.6 W/m2K. Listed fabric and heritage elements carry sensitive exemptions we negotiate with Camden, Haringey or Islington conservation officers. SAP calculations are prepared in-house.
Builds within 1m of the boundary — common on Highgate terraces — require 1-hour fire-resistant external walls and restricted openings facing the boundary. Loft conversions require protected means of escape (30-minute fire doors to the stair, mains-linked alarms). For mansard work on Victorian roofs this is designed alongside the heritage detailing, not after it.
Bedroom-over-bedroom conditions across party walls are the norm on Highgate terraces. Any new wall or floor between dwellings, or forming a new bedroom against an existing party wall, must meet the Part E airborne and impact thresholds. Where we cannot meet the standard through construction alone, pre-completion sound testing is commissioned and certified.
Part M requires level thresholds and 775mm minimum door openings on new builds — occasionally at odds with the narrow corridors of original Highgate plans, which we resolve with the relevant council at Full Plans stage. 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 with deep roots in Highgate and the surrounding North London neighbourhoods.
Our design studio at 250 Finchley Road NW3 is a short journey from Highgate. Visit to see materials, meet the team, and discuss your project in person.
Our RIBA architects have extensive experience with the planning departments, conservation officers and building control teams at Camden, Haringey and Islington — the three councils that determine applications across Highgate. We know what gets approved.
From the Georgian townhouses, Victorian villas, Edwardian mansions and listed buildings on The Grove, South Grove, Pond Square, Highgate West Hill, Hampstead Lane and Cholmeley Park — we understand the specific construction challenges and planning context of every property type in N6.
Our NW3 studio serves the wider catchment. Adjacent North London builders pages: