Tonypandy, South Wales Valleys
Semi-detached rear extension in Tonypandy
Semi-detached rear extension in Tonypandy: 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.
Tonypandy and its postcode districts CF40 are part of our South Wales Valleys coverage. Where a Tonypandy 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 Tonypandy?
For Tonypandy we work from the Wales rate: £1,770–£2,880 per square metre of new floor, including VAT, 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 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a semi-detached rear extension in Tonypandy?
The planning route for a semi-detached rear extension in Tonypandy is set by Wales's householder rules and your council.
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.
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 Tonypandy like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Tonypandy. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How a semi-detached rear extension in Tonypandy 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.
Paperwork handled
Planning or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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.
Semi-detached rear extensions near Tonypandy
Neighbouring places we cover include Rhondda (2.6 miles) and Pontypridd (5.1 miles).
- Semi-detached rear extension in Rhondda
- Semi-detached rear extension in Pontypridd
- Semi-detached rear extension in Mountain Ash
- Semi-detached rear extension in Aberdare
- Semi-detached rear extension in Llantrisant
Other work in Tonypandy:
FAQ
Semi-detached rear extension questions in Tonypandy
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.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Do I need planning permission for a rear extension in Tonypandy?
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 Tonypandy?
Including CF40, and the surrounding South Wales Valleys area.
How long does a rear extension take to build in Tonypandy?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.