Abercarn, South Wales Valleys
Semi-detached rear extension in Abercarn
Semi-detached rear extension in Abercarn: single or two-storey extensions for semi-detached houses, with side access and one party wall. We measure the house, show you what the rules allow, price it in writing and build it.
We cover Abercarn (NP11) as part of our South Wales Valleys work. Where an Abercarn semi already has a small lean-to at the back, we usually replace it rather than extend it.
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 semi-detached rear extension cost in Abercarn?
A semi-detached rear extension in Abercarn is priced at £1,770–£2,880 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 semi-detached rear extension in Abercarn?
Here is how the rules in Wales apply to a semi-detached rear extension in Abercarn.
The Welsh Government's householder rules let many homes add a single-storey rear extension up to 4 metres deep and 4 metres high without a planning application. Deeper projects go through a householder application, because Wales has no prior approval route.
Welsh rules allow a two-storey rear extension without an application only where the ground floor is no deeper than 4 metres, the upper floor no deeper than 3 metres and at least 10.5 metres remains to the rear boundary. Most homeowners still apply for householder planning permission.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development or a householder planning application.
What are homes in Abercarn like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Abercarn. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How a semi-detached rear extension in Abercarn comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Abercarn
Close by, we work in Risca, about 3.1 miles away, and Blackwood, about 3.4 miles away.
- Semi-detached rear extension in Risca
- Semi-detached rear extension in Blackwood
- Semi-detached rear extension in Cwmbran
- Semi-detached rear extension in Bargoed
- Semi-detached rear extension in Gelligaer
Other work in Abercarn:
FAQ
Semi-detached rear extension questions in Abercarn
How long does a rear extension take to build in Abercarn?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
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.
Do I need a party wall agreement?
Usually with the attached neighbour, in England and Wales.
Do I need a party wall agreement?
In Wales, usually yes if the extension is on or near a shared boundary or close to a neighbour's foundations. We serve the notices.
Do I need planning permission for a rear extension in Abercarn?
Often not for a single-storey rear extension of up to 4 metres under Welsh permitted development. Wales has no prior approval route for deeper extensions.
What postcode areas do you cover around Abercarn?
Including NP11, and the surrounding South Wales Valleys area.