House Extension Specialists: Creating Beautiful, Functional Spaces with EA

In Brief
- At Extension Architecture, we are your go-to extension specialists for all types of extensions, from simple to complex expansions.
- Our design and build process is a proven and time-tested approach ensuring quality, precision, and timely delivery.
- Project management has been one of our strengths that ensures transparency, quality, and accountability.
- Our extension specialists carry over 14 years of experience in curating extensions and conversions.
In architecture, if etching out a functionality is science, then crafting aesthetic beauty is an art. A construction outcome will only reach it’s intended culmination when beauty and art amalgamate into delivering a meaningful and impactful space.
At Extension Architecture, we believe that beauty is more about spatial design. Yes, there is beauty in aesthetics, but more than just visual appeal, beauty is more about the craft of an efficient design that exudes function, and how it integrates every element of the space to make it integral.
EA’s House Extension Builders
Whether it is designing a home office, an extended kitchen, or an open plan living area, our house extension builders are not just adept at blending beauty and practicality but also at creating a seamless environment that delivers comfort and productivity. From specialising in straightforward rear and side extensions to complex dormer loft conversion and creating bespoke spaces, our extension builders combine architectural creativity and technical precision to deliver a gamut of extension solutions that last long.
Here’s what you can expect from Extension Architecture’s builders –
- Designing with Intent
- Integrated Process
- Being Specialists
- High Quality Craftsmanship
Why Choose EA for Your House Extension Project?
1. Focused Expertise on Extensions
Our focused expertise in extensions gives us the edge to design spaces that maximise efficiency, integrate the old and new, while offering customised solutions to address complex issues, whether it is removing or adding a load bearing wall, allowing more natural light into the space, opening up a narrow space, and similar other extension challenges.
2. Design and Build Expertise Under One Roof
- Builders working directly with architects and planners from the project’s inception.
- Realistic and buildable designs from the start.
- Transparency with the client at every stage of the project
- Cohesive and seamless communication among all specialists, resulting in a well-informed project that’s intended to succeed
- Cost-effective and high-quality sourcing of materials and craftsmen.
- Timely delivery of the project with minimal to no delays.
3. Project Management
4. Expertise in Planning & Regulatory Issues
From seeking planning permission-related approvals, complying with building regulations, party wall regulations, and other local authority planning rules, we ensure seamless and faster approvals by prioritising project delivery.
5. Progressive Approach
Cost for a House Extension Project
- Design and planning: Architectural drawings, planning applications, structural calculations.
- Construction: Foundations, walls, roofing, doors, windows, and finishes.
- Services: Installing plumbing, electrical, and heating equipment.
- Project management: Site supervision and timeline control.
- Upgrades: Sustainable materials, energy-efficient upgrades, smart technologies (if needed).
- Finishes: Basic kitchen/bathroom, flooring, painting.
Average Extension cost per square metre based on the location –
Type of Extension | London | Rest of UK |
---|---|---|
Single Storey Extension (Basic) | £2,000 to £3,000 | £1,500 to £2,200 |
Single Storey Extension (High-end) | £2,800 to £3,800 | £2,000 to £3,000 |
Double Storey Extension (Basic) | £3,000 to £4,200 | £2,400 to £3,300 |
Double Storey Extension (High-end) | £5,100 to £6,400 | £3,200 to £4,600 |
Loft Conversion | £1,800 to £2,700 | £1,300 to £2,000 |
Average Cost of an extension typical and common of its type across London –
Type of Extension | Size | Cost (basic to high-end finish) | Total Cost |
---|---|---|---|
Single Storey Rear Extension | 12 square metres | £1,800 to £4,500 | £21,600 to £54,000 |
Single Storey Side Return Extension | 12 square metres | £1,500 to £4,200 | £18,000 to £50,400 |
Single Storey Rear Extension | 20 square metres | £1,800 to £4,500 | £36,000 to £90,000 |
Single Storey Side Return Extension | 20 square metres | £1,500 to £4,200 | £30,000 to £84,400 |
Additional Costs to Consider
- Planning permission and approvals: £200 – £2,000 (depending on complexity)
- Party Wall agreements: £1,000 – £3,000 (if needed)
- Building regulations inspections: £750 – £1,500
- Contingency budget: 10–15% of total cost
Conclusion
If your goal is a well-designed, smoothly executed, and compliant extension, let us know about your extension plans and vision. Contact our experts for an initial consultation.