From first ideas to final plans, we make extensions simple
Whether you're dreaming of a new kitchen-diner, extra bedroom, or home office, we'll guide you through every step of your house extension journey.
Add space and value without moving home
A house extension is a construction project that adds floor space to your existing home. Whether it's extending outwards into your garden or upwards with an additional storey, extensions are one of the most popular ways to add space and value to your property.
Extensions can transform how you live in your home, creating open-plan living spaces, dedicated home offices, extra bedrooms, or luxurious kitchen-diners that open onto your garden.
Add valuable living space
Create the room you need without the stress and cost of moving.
Increase property value
Well-designed extensions can add significant value to your home.
Avoid moving costs
Stay in the area you love and avoid stamp duty and agent fees.
Customise to your needs
Design a space tailored precisely to how you and your family live.
Explore the different ways to extend your home
From loft conversions to wraparound extensions — find the right approach for your property.
Loft Conversions
Transform your unused attic into a stunning bedroom, office, or living space with a loft conversion.
Kitchen Extensions
Create your dream open-plan kitchen-diner with bifold doors opening onto your garden.
Garage Conversions
Convert your garage into a functional living space, home office, or extra bedroom.
Single Storey Extensions
Extend your ground floor to create more space for living, dining, or entertaining.
Double Storey Extensions
Double your added space by building up as well as out, ideal for growing families.
Rear Extensions
Extend out into your garden to create more living space, perfect for open-plan kitchen-diners.
Side Extensions
Utilise the side of your property to add extra width and living space to your home.
Side Return Extensions
Utilise the narrow alley alongside your property to widen your ground floor.
Wraparound Extensions
Combine rear and side extensions for maximum space and a dramatic transformation.
See what we've helped homeowners achieve
These are just a fraction of our projects.
Rear ExtensionRear Extension in Cardiff
Single storey rear extension with bifold doors opening to garden
WraparoundWraparound in Manchester
Single storey wraparound extension with corner glazing and bifold doors
Side ReturnSide Return in London
Side return infill creating open-plan kitchen dining space
Loft ConversionLoft Conversion in Birmingham
Dormer loft conversion with en-suite bathroom
How much does a house extension cost?
Extension costs vary by type, size, specification, and location. Use our detailed tables below to estimate your project budget.
Extension Costs in Wales (2026)
Build costs only. Design, planning, and professional fees are additional.
| Extension Type | Budget Basic spec | Average Mid-range | Premium High-end |
|---|---|---|---|
| Rear Extension (Single Storey) | £28k | £42k | £65k |
| Two-Storey Rear Extension | £55k | £85k | £140k |
| Side Return Extension | £25k | £38k | £55k |
| Side Extension | £30k | £48k | £72k |
| Wraparound Extension | £50k | £75k | £120k |
| Loft Conversion | £35k | £52k | £85k |
| Garage Conversion | £12k | £22k | £38k |
| Kitchen Extension | £32k | £50k | £80k |
Prices are estimates based on typical project sizes. Actual costs depend on specification, site conditions, and access.
Cost Per Square Metre by Region
Use these rates to estimate costs for your specific project size.
| Region | Budget (per m²) | Average (per m²) | Premium (per m²) |
|---|---|---|---|
| WalesSelected | £1,400 | £2,100 | £3,000 |
| London | £2,000 | £3,000 | £4,500 |
| South East England | £1,750 | £2,600 | £3,800 |
| Midlands | £1,550 | £2,300 | £3,300 |
| North England | £1,450 | £2,200 | £3,150 |
Why London costs more: Higher labour rates, expensive materials delivery, parking/access restrictions, and greater regulatory requirements all contribute to London's premium of 40-50% compared to Wales.
Additional Professional Fees
These costs are in addition to your construction budget.
| Service | Budget | Average | Premium |
|---|---|---|---|
| Design Services (Planning Drawings) | £1,500 | £2,500 | £4,000+ |
| Planning Application Fee | £450 | £450 | £450 |
| Building Regulations Drawings | £800 | £1,500 | £2,500+ |
| Building Control Fee | £600+ | £700+ | £900+ |
| Structural Engineer | £700+ | £1,100 | £3,000+ |
| Party Wall Surveyor (if needed) | £700 | £1,200 | £2,000+ |
Quick Cost Estimate
Based on Wales average rates (£2,100/m²)
Do you need planning permission?
Many extensions fall under Permitted Development rights, meaning you won't need to apply for planning permission — provided your project meets specific size and design limits.
However, if your property is listed, in a conservation area, or your proposed extension exceeds permitted development limits, a full planning application will be required. We'll assess your project and advise the right route — saving you time and avoiding costly mistakes.
Free assessment of whether your extension qualifies for Permitted Development
Full planning application handling if needed
Listed building and conservation area expertise
Building Regulations drawings for compliance
Your extension journey
From first call to approved plans — we guide you through every step.
Free Consultation
We discuss your ideas, budget and timeline — no obligation, just helpful advice.
Site Survey
We visit your property to measure and assess the space and its full potential.
Design Development
We create tailored design drawings you can compare and refine before progressing.
Planning Submission
We handle the planning application and liaise with the council on your behalf.
Building Regulations
We prepare a complete drawing package for Building Regs and connect you with specialists.
Frequently asked questions
Many extensions fall under Permitted Development rights, meaning you may not need full planning permission. However, size limits, location (such as conservation areas) and listed status can affect this. We'll assess your project and advise the right route.
Our average design time is around 8 weeks from the initial site visit to final drawings, depending on complexity and how quickly you'd like to move.
Costs vary by type, size, specification and region. In Wales, a typical single-storey rear extension averages around £42,000 build cost. Use our pricing tables above for a detailed estimate.
Yes. We prepare all drawings and supporting documents and manage the entire application process, liaising with the council so you don't have to.
Absolutely. We prepare detailed Building Regulations drawings with construction details and material specifications to ensure compliance and help control costs.
Ready to extend your home?
Book a friendly, no-obligation call with our team. We'll listen to your ideas, answer your questions, and explore how we can bring your extension to life.