Cardiff home office extensions, designed and built
Our design and build teams take on home office extensions in Cardiff, from the first measured survey through planning and building control to the finished room.
- Guide price in CardiffFrom £14,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time8–12 weeks on site
- Postcode districtsCF5, CF10, CF11, CF14, CF23
Who a home office extension suits
- Homes where a loft or garden room is not practical
- People who work from home most of the week
- Households that need a second quiet room
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.
What should I budget for a home office extension in Cardiff?
Labour and material costs vary across the UK, so for Cardiff we use our Wales factor (×0.93). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Cardiff: £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.
Planning rules that apply in Cardiff
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.
In a conservation area, national park, National Landscape or World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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).
Covering Cardiff
Our survey diary covers Cardiff, including CF5, CF10, CF11, CF14, CF23, CF24. The same team covers Penarth (3 miles), Barry (7 miles), Cowbridge (12 miles), all within easy reach.
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
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about home office extensions
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Cardiff, 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 home office extension in Cardiff?
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.
Do you cover all of Cardiff?
Yes. We cover Cardiff and the surrounding parts of South Glamorgan. Site visits are free and there is no obligation.
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 Cardiff.
Is an attached office better than a garden office?
An attached office shares the house heating and broadband, adds floor area to the home, and needs no garden path in the rain. A garden building can be cheaper and quicker but is a separate structure.
Book a free site visit in Cardiff
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.