Coity, South Wales Valleys
Single-storey rear extension in Coity
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We design, get the approvals for and build single-storey rear extensions in Coity and the surrounding area, with one contract from the first survey to building control sign-off.
Coity and its postcode districts CF31, CF32 and CF35 are part of our South Wales Valleys coverage. A depth of 3 to 4 metres keeps many single-storey rear extensions in Coity within permitted development, subject to the house's planning history.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a single-storey rear extension cost in Coity?
In Coity, our guide for a single-storey rear extension is £1,770–£2,880 per square metre including VAT for a standard specification. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,000–£34,500 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£57,500 |
| 4 m wide × 6 m deep (24 m²) | £42,500–£69,000 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a single-storey rear extension in Coity?
Whether your single-storey rear extension in Coity needs a planning application depends on its size, your house and any local restrictions.
In Wales a single-storey rear extension can often be permitted development if it projects no more than 4 metres beyond the rear wall and is no more than 4 metres high. Wales has no prior approval route for deeper extensions, so anything bigger needs a householder planning application.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Coity like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Coity. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How a single-storey rear extension in Coity comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check or householder planning application, then Building Regulations drawings to the Welsh Approved Documents and structural calculations, plus party wall notices where they apply.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Single-storey rear extensions near Coity
Neighbouring places we cover include Bridgend (1.5 miles) and Aberkenfig (2.1 miles).
- Single-storey rear extension in Bridgend
- Single-storey rear extension in Aberkenfig
- Single-storey rear extension in Pyle
- Single-storey rear extension in Porthcawl
- Single-storey rear extension in Maesteg
Other work in Coity:
FAQ
Single-storey rear extension questions in Coity
Do you handle building control in Coity?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
What postcode areas do you cover around Coity?
Including CF31, CF32 and CF35, and the surrounding South Wales Valleys area.
Does it add value to the house?
Nationwide's October 2025 house price research found that a 10% increase in floor area is linked to about 5% higher value on average. It is a guide, not a promise; local agents can tell you what extended homes on your street sell for.
Can you match the brick or stone on my Coity house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.