Double-storey extensions for homes in Penarth
We design and build double-storey extensions for houses in Penarth, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in PenarthFrom £35,000 inc VAT
- PlanningUsually a planning application
- Build time16–24 weeks on site
- Postcode districtsCF64
Will the council need to approve it?
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 Penarth 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.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Working in Penarth
We cover Penarth and the postcode districts CF64. Nearby, we also take on projects in Cardiff (3 miles), Barry (5 miles), Cowbridge (12 miles).
Just over the Mid Glamorgan border, Caerphilly is about 10 miles away. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
What we take care of
- Measured survey, design and planning drawings
- Breaking through at both levels, stairs and landing changes where needed
- Ground and first floor structure, roof tied into the existing roof
- Foundations sized for two floors
- Insulation, plastering, electrics and plumbing to finish
- Householder planning application where needed
What should I budget for a double-storey extension in Penarth?
Labour and material costs vary across the UK, so for Penarth we use our Wales factor (×0.93). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Penarth: £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.
Our process, step by step
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Your questions about a double-storey extension in Penarth
Do I need building regulations approval in Penarth?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Penarth?
Yes. We cover Penarth and the surrounding parts of South Glamorgan. Site visits are free and there is no obligation.
Will my neighbours in Penarth 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 Penarth
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.