Home office extensions across County Down
Our design and build teams take on home office extensions in County Down, from the first measured survey through planning and building control to the finished room.
- Guide priceFrom £13,500 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Towns covered5
- Site visitFree, no obligation
Towns in County Down
Local to County Down
Towns we cover in County Down include Bangor, County Down, Newtownards, Newry, Banbridge, Downpatrick. Northern Ireland's housing ranges from city terraces to large numbers of detached houses and bungalows on rural plots, many in render, where single-storey extensions fit easily.
How much does a home office extension cost in County Down?
Prices below are for County Down, using the Northern Ireland factor of ×0.86. They are guide ranges including VAT for the build only, not a quote.
Typical rates in County Down: £1,590 to £2,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 3.2 m 8 m² | £13,500 – £16,500 | £14,500 – £19,000 | £18,500 – £23,500 |
| 3 m × 3.6 m 11 m² | £17,500 – £21,000 | £20,000 – £26,000 | £25,500 – £32,500 |
| 3 m × 5 m 15 m² | £23,500 – £28,500 | £27,500 – £35,000 | £34,500 – £44,000 |
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in County Down
In Northern Ireland the Planning (General Permitted Development) Order 2015 lets some single-storey rear extensions go ahead without planning permission, up to 3 m on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Larger, side and two-storey extensions normally need planning permission from the council, and building control approval is separate.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building close to a public sewer needs the agreement of NI Water, which we check during design.
In Northern Ireland building control is run by the councils under the Building Regulations (Northern Ireland). We submit full plans or a building notice and book the inspections through to completion.
Applications are decided by your council, which handles local planning in Northern Ireland.
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
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
We visit your County Down home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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.
Home office extension questions answered
How long does a home office extension take to build in County Down?
On site, typically 8 to 12 weeks once approvals are in place. Before that, allow 4–10 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for County Down, 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 County Down?
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 £1,590 to £2,920 per m² including VAT. An 11 m² standard-spec office is typically £20,000 to £26,000 in County Down.
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 County Down
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.