Orange Key Architectural Design Studio

House Extension Design in Berkshire & Oxfordshire

Considered, buildable extension design — from a single-storey rear extension to a wrap-around remodel — with the planning and building-regulation drawings handled under one roof.

House extension · Berkshire & Oxfordshire

A house extension is one of the most effective ways to add space and value to a home without the upheaval of moving. Orange Key designs house extensions for homeowners across Berkshire and Oxfordshire — including Reading, Newbury, Wokingham, Maidenhead, Oxford, Abingdon and Didcot — developing proposals that respond to the character of the existing property while improving how the home works day to day.

Our architectural design service takes a project from the first sketch through to a planning submission and a full set of technical drawings. Because the design and the drawings are produced in-house, nothing is lost between firms — and you have a single point of contact throughout.

Types of house extension we design

Every property is different, and the right approach depends on the layout of the house, the size of the plot and any planning constraints. The extensions we most often design include:

  • Single-storey rear extensions — open-plan kitchen, dining and living space
  • Side extensions — reclaiming a side return or narrow plot
  • Double-storey extensions — added living space below and a bedroom or bathroom above
  • Wrap-around extensions — combining rear and side to transform the ground floor
  • Kitchen & open-plan living extensions — light-filled space with glazing and rooflights

At the early design stage we explore layout options with you and assess what is achievable within local planning policy and permitted development rights.

Do I need planning permission for a house extension?

Many single-storey extensions fall within permitted development, while larger, two-storey and wrap-around extensions — and properties in conservation areas — usually require planning permission. The right route depends on the size and position of the extension and the constraints affecting your property.

We prepare the planning permission drawings required for an application and can manage the submission on your behalf, including responding to any queries the local planning authority raises during the determination period.

From planning to building regulations

Once planning permission is in place, a detailed technical package is needed before work can begin on site. We prepare building regulations drawings and coordinate with a structural engineer where required, so the design can be built safely and signed off by building control.

Project · Kintbury, Berkshire

“At The Millers House we designed a contemporary glazed extension to a period family home, taking the project from concept through to a successful planning submission.”

The Millers House — a house extension project by Orange Key

House extensions across Berkshire & Oxfordshire

We work on residential extension projects throughout both counties, and our familiarity with the local planning authorities — from Reading and Wokingham to Oxford and Abingdon — helps us develop proposals that respond to both planning policy and the practicalities of building. You can see the full list of areas we cover across Berkshire and Oxfordshire, or read our guide to how much a house extension costs before you begin.

If you are considering extending your home, we would be happy to talk your project through. At an early stage we can review the property and advise on the most sensible way forward.

Common questions

House extension FAQs

Do I need planning permission for a house extension in Berkshire?

Many house extensions fall within permitted development, but larger, two-storey or wrap-around extensions — and homes in conservation areas — usually require planning permission. We assess the likely route early and prepare the planning drawings where they are needed.

How much does a house extension cost?

As a broad guide, single-storey extensions typically cost around £2,000–£3,000 per m² to build, and two-storey extensions around £1,800–£2,800 per m², before design, planning and building control fees. See our extension cost guide for a fuller breakdown.

Do I need building regulations approval for an extension?

Almost all house extensions require building regulations approval, separate from planning permission. We prepare the detailed building regulations drawings and coordinate with a structural engineer where needed, so the work can be built and signed off.

How long does the design and drawings process take?

Initial design proposals usually take a few weeks. Where planning permission is required, the local authority determination period is typically around eight weeks. Building regulations drawings are then prepared so contractors can price and build the project.

Explore

Related services

Get started

Thinking about extending your home?

Tell us about your property and what you would like to achieve in Berkshire or Oxfordshire — we would be happy to talk it through.

01865 578931