A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
Looking for a single-storey extension in West Glamorgan? We organise the whole job, bringing in the trades it needs under one agreement, and you have a single contact. We cover Swansea, Neath, Briton Ferry and Gorseinon, along with villages and suburbs nearby. The rules in Wales decide what consents are needed, and our guide range of £32,000–£69,000 including VAT gives you a realistic starting point for a budget.
- Guide price
- £32,000–£69,000 inc VAT
- Time on site
- 10–16 weeks on site
- Planning rules
- Wales
- Price level
- About 8% below the national guide
- Towns listed
- 5
- Survey
- Free, with a written quote
How much does a single-storey extension cost in West Glamorgan?
What will a single-storey extension cost in West Glamorgan? Our guide range is £32,000–£69,000 including VAT. That figure is adjusted for Wales, about 8% below the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in West Glamorgan |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £20,000–£37,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £32,000–£69,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £64,000–£120,000 |
What moves the price up or down:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
What do you get?
- Groundworks, foundations and below-ground drainage
- Cavity walls built and insulated to building regulations
- Flat or pitched roof, with rooflights or a lantern if specified
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Building control inspections and completion certificate
Homes in West Glamorgan
Swansea's Victorian terraces climb its hillsides, its centre was largely rebuilt after wartime bombing, and Neath and Port Talbot have industrial terraces and post-war estates. Gower villages have stone cottages, and Pennant sandstone is common in older walls. Newer estates have grown on the edges of the main towns.
Hillside terraces often need repointing, rendering, roof repairs and window replacement, and loft conversions can work well. Gower stone cottages call for lime-based repairs, and estate homes commonly take extensions and driveways.
Swansea Bay and Gower face wet westerly weather and salt, and steep streets can affect access and scaffolding.
Do you need permission in West Glamorgan?
The notes below cover Wales, which is where West Glamorgan sits. Rules change and every property is different, so we speak to the council before pricing your job.
In Wales, permitted development allows many single-storey rear extensions, with depth and height limits that depend on the type of house and how close the extension comes to your boundaries. Side extensions, listed buildings, conservation areas and flats usually need planning permission.
Building Regulations in Wales apply to extensions, from foundations to insulation and fire safety. The Party Wall etc. Act 1996 applies in Wales as it does in England.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Survey and measure
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a single-storey extension.
Your fixed price
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Plan and prepare
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a single-storey extension are in place before the first day on site.
Build and hand over
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
What you can expect from us
Frequently asked questions
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Can we stay at home during the build?
Most people stay at home while we build a single-storey extension, because the new structure goes up outside before we break through. The disruptive part is usually the last few weeks, when we open into the house and fit the kitchen. We put up dust screens, keep a safe route through the house and agree a temporary kitchen setup if needed. Water and power are only off for short, planned periods.
Which postcodes in West Glamorgan do you cover?
We cover SA1, SA10, SA12 and SA4, along with the rest of West Glamorgan. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
Do I need planning permission for a single-storey extension?
Whether you need planning permission depends on the extension's size and height, how close it is to boundaries, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. In England, many rear extensions up to 3m deep on a semi or terrace, or 4m on a detached house, can be built under permitted development. We check the rules that apply to your home before quoting.
What is the Party Wall Act and does it apply to me?
The Party Wall etc. Act 1996 applies in England and Wales only. In England and Wales, it requires you to give notice to neighbours before certain work on or near a shared wall, such as digging foundations within 3m of their building and deeper than its footings. Neighbours can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act, though general rights still apply. We identify whether notices are needed during the survey.
Towns in West Glamorgan
We offer a single-storey extension in each of the towns below, all within West Glamorgan. Select yours for guide prices, postcodes covered and nearby places.