Home office extensions in Belfast
A home office extension in Belfast starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in BelfastFrom £13,500 inc VAT
- PlanningNI permitted development (rear 3–4 m) or planning
- Build time8–12 weeks on site
- Postcode districtsBT1, BT2, BT6, BT7, BT12
Is a home office extension right for your house?
- People who work from home most of the week
- Homes where a loft or garden room is not practical
- Households that need a second quiet room
Extensions in and around Belfast
Across BT1, BT2, BT6, BT7, BT12, BT13, we can visit, measure and advise. Nearby, we also take on projects in Castlereagh (2 miles), Newtownabbey (4 miles), Lisburn (7 miles), Carrickfergus (10 miles).
In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
Guide prices for Belfast
These guide figures apply our Northern Ireland adjustment (×0.86) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Belfast: £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 |
For a figure based on your own dimensions, use our guide-price tool.
Planning and approvals in Belfast
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.
The planning position for a specific Belfast address depends on its history and any designations, which is why we check it at the first visit.
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.
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 Belfast home, measure up, talk through what you want and check the planning position.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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
Do you cover all of Belfast?
Yes. We cover Belfast and the surrounding parts of County Antrim. Site visits are free and there is no obligation.
Do I need building regulations approval in Belfast?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Belfast be involved?
If a planning application is needed, the council notifies neighbours. Where work is close to a shared boundary, we agree access and protection with them in writing.
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 £1,590 to £2,920 per m² including VAT. An 11 m² standard-spec office is typically £20,000 to £26,000 in Belfast.
Book a free site visit in Belfast
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.