Home office extensions in Caerphilly
Caerphilly homeowners can use us for the whole home office extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in CaerphillyFrom £14,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time8–12 weeks on site
- Postcode districtsCF83
What should I budget for a home office extension in Caerphilly?
Prices below are for Caerphilly, using the Wales factor of ×0.93. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Caerphilly: £1,720 to £3,160 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 3.2 m 8 m² | £14,500 – £18,000 | £15,500 – £20,500 | £20,000 – £25,500 |
| 3 m × 3.6 m 11 m² | £18,500 – £23,000 | £21,500 – £28,000 | £27,500 – £35,000 |
| 3 m × 5 m 15 m² | £25,500 – £31,000 | £29,500 – £38,000 | £37,500 – £47,500 |
For a figure based on your own dimensions, use our guide-price tool.
Included in a typical project
- Layout for desk, storage and video calls
- Window and rooflight placement to avoid screen glare
- Sound insulation to the adjoining rooms
- Data cabling and plenty of sockets
North-facing glass and rooflights give steadier light for screen work. Where the office faces south, we use deeper reveals or external shading to keep glare and heat down.
Will the council need to approve it?
In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.
Homes in conservation areas, national parks, National Landscapes (AONBs) and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
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).
Extensions in and around Caerphilly
Site visits are available across Caerphilly (CF83). We also work in nearby Risca (6 miles), Pontypridd (6 miles), Gelligaer (6 miles), Blackwood (6 miles).
For homes towards South Glamorgan, Cardiff is around 7 miles away. 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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Caerphilly
Do I need building regulations approval in Caerphilly?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Caerphilly?
Yes. We cover Caerphilly and the surrounding parts of Mid Glamorgan. Site visits are free and there is no obligation.
Who do I contract with for a home office extension in Caerphilly?
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.
How much does a home office extension cost?
Our guide range is about £1,720 to £3,160 per m² including VAT. An 11 m² standard-spec office is typically £21,500 to £28,000 in Caerphilly.
Can I claim the cost against tax?
Building work on your home is not normally an allowable business expense, and claiming it can have capital gains tax effects. Speak to an accountant before assuming any tax relief.
Book a free site visit in Caerphilly
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.