Double-storey extensions across Merthyr Tydfil
We design and build double-storey extensions for houses in Merthyr Tydfil, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in Merthyr TydfilFrom £35,000 inc VAT
- PlanningUsually a planning application
- Build time16–24 weeks on site
- Postcode districtsCF47, CF48
Planning rules that apply in Merthyr Tydfil
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.
The planning position for a specific Merthyr Tydfil address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. Wales has its own building regulations and approved documents; the council or a registered building control approver checks the plans, inspects the work and issues a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent before the foundations go in.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
What we take care of
- Foundations sized for two floors
- Ground and first floor structure, roof tied into the existing roof
- Householder planning application where needed
- Building regulations drawings and structural design
- Measured survey, design and planning drawings
How much does a double-storey extension cost in Merthyr Tydfil?
For Merthyr Tydfil we adjust our national guide rates by ×0.93, the factor we use for Wales. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Merthyr Tydfil: £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 |
Want a range for your exact size? The guide-price tool takes about a minute.
Local to Merthyr Tydfil
Our survey diary covers Merthyr Tydfil, including CF47, CF48. Neighbouring towns we cover include Aberdare (4 miles), Rhondda (7 miles), Gelligaer (8 miles), Blackwood (9 miles).
Ebbw Vale, in Gwent, is roughly 8 miles from Merthyr Tydfil 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.
How the project works
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 produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Merthyr Tydfil
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Merthyr Tydfil, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Merthyr Tydfil 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.
Who do I contract with for a double-storey extension in Merthyr Tydfil?
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.
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 Merthyr Tydfil
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.