Architects for Extensions & Planning Applications  in Oxford

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

All In One Architectural Solution In Oxford Architects

Planning applications handled for Oxford City Council — 8-week standard decision target.
Conservation areas affects some Oxford 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 Oxford projects to date.

Extension Architecture handles planning applications, house extensions, and loft conversions across Oxford and the wider Oxford City Council area, including OX1, OX2, OX3, OX4. Conservation areas 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

35⁺

Projects completed in Oxford Architects

2220 ⁺

Our total projects completed in London & Surrey

Locations in Oxford Architects

Barton • Blackbird Leys • Cowley • Cowley Marsh • Cutteslowe • Headington • Headington Quarry • Hollow Way • Iffley • Jericho • Littlemore • Marston • New Hinksey • North Oxford • Rose Hill • Sandhills • Summertown • Temple Cowley • Walton Manor • Wolvercote • Wood Farm

Postcodes Served

OX1, OX2, OX3, OX4

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 Architects Oxford Extension & Loft Conversion Projects

What makes Oxford Special?

Oxford, the place famous for its world-renowned university, experiences rich, legal architecture with a sense of intellectual curiosity in the atmosphere. The city has iconic architecture with extremely old structures that reflect its academic heritage but the residential properties play a wide role in creating an identity for the city too. Oxford’s residential scene features Georgian, and Victorian homes, blending traditional and modern styles. As one moves towards Central Oxford, one can find stone or brick historic townhouses with architectural elements like iron railings, and tall sash windows. These homes are often found around the cobbled streets set near the university.

However, the outskirts of Oxford feature more modernistic developments, built around the 20th and 21st century. This includes detached and semi-detached properties with contemporary, sleek designs, open-floor layouts and sustainable features. Loft conversions, basement renovations, and kitchen extensions are also common in the area so that residents can fully utilize this space within the usually small, historic construction. Stringent planning regulations by Oxford council have allowed for extension and sensible growth which respects the historical context of the city. This subtle balance allows both elements, heritage and modernity, to be maintained in the architecture, which is quite innovative in both functionality and visual appeal and thus aids in enhancing the overall residential landscape of the city.

Oxford has a mix of Victorian, Edwardian, and 1930s properties across OX1.
Conservation areas affects some Oxford streets — always verify your specific address.
Well-designed extensions consistently add long-term value to Oxford properties.
Oxford Council runs a clear 8-week householder planning decision process.

Interior fit-out, Oxford

What Our Clients Say About
Extension Architecture

Interior fit-out, Oxford

Oxford Planning Applications and Architectural Services

In Oxford, an affluent suburb with a largely well-established community, extensions and refurbishments are the most sought-after projects among homeowners, especially around the outskirts. This reflects their interest in not only increasing their property’s value but also improving the comfort and functionality of their living spaces. Often homeowners often hope to go down the Permitted Development route thinking it will be much easier, however, this is not always the case.

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 Oxford Architects 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 Oxford 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 Oxford City Council. However, conservation areas + article 4 + listed restrictions mean many Oxford 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. Oxford City Council 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 Oxford varies depending on the size, type, specification, and your contractor’s pricing. As a rough guide, single-storey rear extensions in the OX1, OX2, OX3, OX4 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 Oxford are governed by a combination of national Permitted Development rules and local Oxford City Council 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 OX1, OX2, OX3, OX4. However, conservation areas + article 4 + listed means some properties lose PD rights and all loft conversion types require a full planning application from Oxford City Council. 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.

Oxford City Council 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 Oxford City Council 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 Oxford City Council 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 Oxford 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 Oxford City Council assesses householder applications, including the conservation areas + article 4 + listed constraints specific to Oxford. 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 OX1, OX2, OX3, OX4 and beyond.

Architects for Extensions & Planning Applications  in Oxford