Architects for Extensions & Planning Applications  in Finchley

Planning permission, architectural design and project management  delivered end-to-end by a multi-award-winning local team.

All In One Architectural Solution In Finchley

Planning applications handled for Barnet Council — 8-week standard decision target.
Conservation areas in finchley affects some Finchley properties — we always check first.
Full design, planning, and building regulations service under one fixed fee.
Loft conversions available — Velux, dormer, and hip-to-gable options in-house.
In-house structural engineer included — no separate specialist ever needed.
98% planning approval rate across all completed Finchley projects to date.

Extension Architecture handles planning applications, house extensions, and loft conversions across Finchley and the wider London Borough of Barnet area, including N3, N12, N2. Conservation areas in Finchley restrictions affect some properties. Our in-house structural engineer and RIBA-chartered team manage every stage. Council decisions take 8 weeks. Get your free quote today.

We only deliver excellence

80⁺

Projects completed in Finchley

2220 ⁺

Our total projects completed in London & Surrey

Locations in Finchley

Barnet • Chipping Barnet • East Barnet • New Barnet • High Barnet • Finchley • North Finchley • West Finchley • East Finchley • Golders Green • Hendon • Colindale • Mill Hill • Edgware • Burnt Oak • Totteridge • Whetstone • Cricklewood • Childs Hill • Brunswick Park • Friern Barnet • New Southgate

Postcodes Served

N3, N12, N2

Our Expertise

Planning Application Drawings
Council-ready drawings, fast

3D Visualisations
See it before building

Retrospective Planning
Fix unpermitted works

Building Regulation Drawings
Safe, compliant drawings

Commercial Development Consultancy
Change of use experts

Interior Design
Finishes inside out

Spatial Planning & Layout
Smarter room layouts

Feasibility Consultancy
Know what’s possible

Recent Finchley Architects Extension & Loft Conversion Projects

What makes Finchley Special?

Finchley, North London is known for its history, diverse community, and an urban charm mixed with suburbia. The tapestry of styles that is reflected in the residential architecture makes it unique for every taste. Most of the area’s housing is Victorian, Edwardian, and 1930s, with some modern developments. This gives Finchley its distinctive architectural character.Victorian homes are mostly found with bay windows, tall ceilings, and detailed brickwork. They are almost always equipped with front gardens, which add to their curb appeal. Edwardian houses are a bit newer than their Victorian relatives but are also larger in design.

The 1930s saw the boom of semi-detached homes, with styles that were unique to the interwar period. Many of these homes have been upgraded to suit modern lifestyles but retain their original charm, which makes them popular among buyers today. Modern apartment buildings and townhouses characterise Finchley’s housing landscape, equipped with modern features and minimalistic designs that attract young professionals as well as growing families. Finchley’s architectural diversity, with good connectivity and green spaces, makes it a sought-after neighbourhood for those who appreciate tradition blended with convenience. Its historical charm provides contrast with contemporary living but offers a different kind of residential experience within London.

Finchley has a mix of Victorian, Edwardian, and 1930s properties across N3.
Conservation areas in finchley affects some Finchley streets — always verify your specific address.
Well-designed extensions consistently add long-term value to Finchley properties.
London Council runs a clear 8-week householder planning decision process.

Interior fit-out, Finchley

What Our Clients Say About
Extension Architecture

Interior fit-out, Finchley

Finchley Planning Applications and Architectural Services

In Finchley, an affluent suburb where most families have been there for generations, extensions and refurbishment are the most common applications that homeowners seek. The residents are not only interested in value addition but also in maximising comfort and functionality. As is the case with most homeowners, they go about it thinking it’s the easier route, Permitted Development, but in actual fact, it is not the case.

Obviously, every residential and commercial project is unique in special requirements and challenges with respect to its fabric. Planning law and the building regulations guide us safely through the stages in which our profound understanding and knowledge come of use. Periodically we have been able to encourage a network of mature other consultants and contractors, enabling them to suggest, guide, and accompany their journey through a project.

Get A Free Quote Today Call Us

Explore before & after visuals of our extension builder projects

See Portfolio

Before

After

Why choose Extension Architecture?

Our experienced team of Finchley architects will take the lead and create a thoughtful design that maximizes the available space and is tailored to your tastes. We will guide you through the intricacies of the planning process and discuss every aspect of the project in detail. Our architects will carefully survey your property to ensure no detail is overlooked. We will be with you throughout the process, providing clearand comprehensive instructions while walking you through the planning, application and construction process.

One-Stop Solution

Our firm provides a comprehensive range of services under one roof, from planning and architectural design to intricate interior and immersive design, and expertly manages the complexities of the construction process. We have delivered projects of various scales and budgets, from small home extensions to large new builds, for a diverse clientele.

In-house Structural Engineer

Our in-house structural engineer—an advantage that only 1 in 20 firms can offer. This is crucial, as significant time is often lost consulting multiple specialists, which can lead to additional costs. With a structural engineer on our team, we ensure a fully collaborative and seamless design-build process, minimizing contingencies and preventing design inaccuracies.

Interior Design + Architecture

Our team includes interior designers who work closely with the clients, especially the ‘ladies’ of the house to curate the dream spaces tailored to their requirements. These processes include fun yet crucial processes like selecting wall finishes, color schemes, soft furnishings, flooring. Having architects and interior designers under one roof allows for less contingencies.

Turn-Key Approach

We provide support throughout the entire building process, embracing a ‘turnkey approach’ to ensure a smooth and efficient project from start to finish. Additionally, we assist in reducing build costs by aiding in the procurement of all internal fit-outs, including sanitaryware, kitchens, and more. It’s a zero hassle solution for clients.

Start Planning an Extension Home Today

If you are planning a house extension in London, our architects can guide you through the entire process from concept design to construction.

Get A Free Quote Contact Us

Architectural design consultation and home extension planning services

Years of Experience

17

Any Questions?

Didn’t find your answer? Feel free to reach out

Whether you need planning permission for a house extension in Finchley depends on your specific address and the type of extension proposed. Most single-storey rear extensions qualify as Permitted Development — allowing you to build up to 3 metres beyond a terraced or semi-detached house, or 4 metres beyond a detached house, without making a planning application to London Borough of Barnet. However, conservation areas in finchley restrictions mean many Finchley properties do not retain standard PD rights. Article 4 Directions, conservation area designations, and Green Belt land all remove PD rights and require a full householder application. London Borough of Barnet targets an 8-week decision from the date your application is validated. Our team checks your specific address, confirms your PD eligibility, and advises on the most appropriate planning route at no charge before any design fee is agreed or any work is commissioned.

The cost of a house extension in Finchley varies depending on the size, type, specification, and your contractor’s pricing. As a rough guide, single-storey rear extensions in the N3, N12, N2 area typically run from around £1,800 per square metre for a standard specification up to £2,800 per square metre or more for a high-end finish. A typical 20-square-metre rear extension therefore costs in the region of £36,000–£56,000 for the construction alone. On top of that, you should budget for architectural drawings, planning application, structural engineering calculations, building regulations drawings and inspections. Our fixed-fee service covers all design and planning stages in one agreed package, and our in-house structural engineer means no separate structural fee. We provide a full cost breakdown at the feasibility stage before any commitment is required.

Loft conversions in Finchley are governed by a combination of national Permitted Development rules and local London Borough of Barnet policies. Under PD, you can add up to 40 cubic metres of additional roof space on a terraced house or 50 cubic metres on a detached or semi-detached house. Rear dormers, Velux rooflights, and hip-to-gable conversions are among the most common options across N3, N12, N2. However, conservation areas in finchley means some properties lose PD rights and all loft conversion types require a full planning application from London Borough of Barnet. Any property in a conservation area, listed building, or Article 4 zone will need planning. Building Regulations approval under Parts B, K, and L is always required regardless of PD status and covers fire safety, structural integrity, and thermal performance. Our team advises on PD eligibility free before any design work.

London Borough of Barnet targets an 8-week decision period for standard householder planning applications from the date of validation. Validation typically takes 5–10 working days from submission, assuming your application is complete and all required documents are included. Conservation area applications and applications requiring a design and access statement may take up to 13 weeks. If London Borough of Barnet requests further information, the 8-week clock can be paused, which is one reason why well-prepared, complete applications are so important. Pre-application advice from London Borough of Barnet is available and typically takes 4–6 weeks to receive a written response. Once granted, planning permission is valid for 3 years from the decision date. Our team manages the full submission process, monitors your application through the council’s portal, and responds to any queries or requests for information without delay.

Extension Architecture is a RIBA-chartered, ARB-registered architectural practice with extensive experience handling planning applications and house extension projects across Finchley and the surrounding area. Our team includes an in-house structural engineer — meaning you do not need to appoint a separate structural engineer, saving both cost and coordination time. We hold a 98% planning approval rate across all submitted applications and understand how London Borough of Barnet assesses householder applications, including the conservation areas in finchley constraints specific to Finchley. From your first enquiry, we offer a free feasibility assessment covering PD eligibility, planning routes, and realistic timescales — no design fee is charged until you are happy to proceed. We handle everything from initial survey and design through planning submission, building regulations, and contractor procurement across N3, N12, N2 and beyond.

Architects for Extensions & Planning Applications  in Finchley