Double-storey extensions across Porthcawl
Planning a double-storey extension in Porthcawl? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in PorthcawlFrom £35,000 inc VAT
- PlanningUsually a planning application
- Build time16–24 weeks on site
- Postcode districtsCF36

Double-storey extension prices in Porthcawl
Labour and material costs vary across the UK, so for Porthcawl we use our Wales factor (×0.93). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Porthcawl: £1,440 to £2,790 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £35,000 – £42,500 | £40,000 – £52,500 | £51,000 – £67,000 |
| 4 m × 4 m, two floors 32 m² | £46,000 – £55,500 | £53,500 – £70,000 | £68,000 – £89,500 |
| 4 m × 6 m, two floors 48 m² | £69,000 – £83,000 | £80,000 – £105,000 | £102,500 – £134,000 |
For a figure based on your own dimensions, use our guide-price tool.
Planning rules that apply in Porthcawl
In Wales a rear extension of more than one storey can be permitted development only if the ground floor projects no more than 4 m, the upper floor no more than 3 m, it stays at least 10.5 m from the rear boundary and it is not in a conservation area, national park, National Landscape or World Heritage Site. Anything larger needs a planning application to the council.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Who a double-storey extension suits
- Homeowners who would otherwise consider moving
- Growing families who need a bedroom as well as a bigger kitchen
- Houses with enough distance to the rear or side boundary
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Covering Porthcawl
Across CF36, we can visit, measure and advise. We also work in nearby Bridgend (6 miles), Maesteg (9 miles), Tonypandy (15 miles), Rhondda (17 miles).
Cowbridge, in South Glamorgan, is roughly 11 miles from Porthcawl and also on our list. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Porthcawl
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Porthcawl, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a double-storey extension in Porthcawl?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will my neighbours in Porthcawl be involved?
If a planning application is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,440 to £2,790 per m² of new floor area including VAT, compared with £1,630 to £3,160 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Porthcawl
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.