Penarth, Cardiff and the Vale
Single-storey rear extension in Penarth
Single-storey rear extension in Penarth: ground-floor space across the back of the house, usually for a kitchen, dining or family room. We measure the house, show you what the rules allow, price it in writing and build it.
We cover Penarth (CF64) as part of our Cardiff and the Vale work. A depth of 3 to 4 metres keeps many single-storey rear extensions in Penarth 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 Penarth?
In Penarth, 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a single-storey rear extension in Penarth?
The planning route for a single-storey rear extension in Penarth is set by Wales's householder rules and your council.
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.
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 Penarth like to extend?
Older terraces near the centre and post-war semis further out are typical of Penarth. Sloping sites are common in Wales, so floor levels and retaining walls are designed at the start.
How a single-storey rear extension in Penarth 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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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 Penarth
Neighbouring places we cover include Cardiff (2.9 miles) and Whitchurch (5.4 miles).
- Single-storey rear extension in Cardiff
- Single-storey rear extension in Whitchurch
- Single-storey rear extension in Barry
- Single-storey rear extension in Rhiwbina
- Single-storey rear extension in Caerphilly
Other work in Penarth:
FAQ
Single-storey rear extension questions in Penarth
Can you match the brick or stone on my Penarth house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.
Is a flat roof or a pitched roof better?
A warm flat roof keeps the extension low under first-floor windows and suits a roof lantern; a pitched or lean-to roof gives a vaulted ceiling. Both last for decades when built properly.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Do I need planning permission for a rear extension in Penarth?
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.
How long does a rear extension take to build in Penarth?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.