Home office extensions across Barry
From the first sketch to final sign-off, we plan and build home office extensions in Barry and the surrounding South Glamorgan area.
- Guide price in BarryFrom £14,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time8–12 weeks on site
- Postcode districtsCF62, CF63

How much does a home office extension cost in Barry?
These guide figures apply our Wales adjustment (×0.93) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Barry: £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 |
Try the guide-price tool to see a range for your own size and finish.
Extensions in and around Barry
We cover Barry and the postcode districts CF62, CF63. Nearby, we also take on projects in Penarth (5 miles), Cardiff (7 miles), Cowbridge (8 miles).
Welsh housing ranges from stone terraces in the valleys to render-and-slate houses and modern estates, and the Welsh planning rules differ from England's in several places.
When a home office extension makes sense
- Households that need a second quiet room
- Homes where a loft or garden room is not practical
- People who work from home most of the week
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.
Planning rules that apply in Barry
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.
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.
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).
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions people ask about home office extensions
Who do I contract with for a home office extension in Barry?
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 Barry?
Yes. We cover Barry and the surrounding parts of South Glamorgan. Site visits are free and there is no obligation.
How long does a home office extension take to build in Barry?
On site, typically 8 to 12 weeks once approvals are in place. Before that, allow 4–10 weeks design and approvals.
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.
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 Barry.
Book a free site visit in Barry
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.