Bridgend, South Wales Valleys
Semi-detached rear extension in Bridgend
Single or two-storey extensions for semi-detached houses, with side access and one party wall. We design, get the approvals for and build rear extensions for semi-detached houses in Bridgend and the surrounding area, with one contract from the first survey to building control sign-off.
Bridgend and its postcode districts CF31 and CF35 are part of our South Wales Valleys coverage. Semi-detached houses are common across the South Wales Valleys, and their side access makes rear extensions quicker to build.
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 Bridgend?
In Bridgend, our guide for a semi-detached 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 semi-detached rear extension in Bridgend?
Here is how the rules in Wales apply to a semi-detached rear extension in Bridgend.
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. 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 Bridgend like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Bridgend. Sloping sites are common, so floor levels and retaining walls are designed at the start. Where a Bridgend semi already has a small lean-to at the back, we usually replace it rather than extend it.
How a semi-detached rear extension in Bridgend 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
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.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Semi-detached rear extensions near Bridgend
Close by, we work in Coity, about 1.5 miles away, and Aberkenfig, about 2.5 miles away.
- Semi-detached rear extension in Coity
- Semi-detached rear extension in Aberkenfig
- Semi-detached rear extension in Pyle
- Semi-detached rear extension in Porthcawl
- Semi-detached rear extension in Llantwit Major
Other work in Bridgend:
FAQ
Semi-detached rear extension questions in Bridgend
Do you handle building control in Bridgend?
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 Bridgend?
Including CF31 and CF35, and the surrounding South Wales Valleys area.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
How much does a semi-detached rear extension cost in Bridgend?
As a guide, £1,770–£2,880 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £21,000–£34,500 at that rate. Your written price follows the survey.
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.
How long does a rear extension take to build in Bridgend?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.