Bedroom extensions for homes in Belfast
If you live in Belfast and want more space without moving, a bedroom extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in BelfastFrom £22,000 inc VAT
- PlanningUsually needs planning permission
- Build time14–22 weeks on site
- Postcode districtsBT1, BT2, BT6, BT7, BT12
Is a bedroom extension right for your house?
- Multi-generational households
- Homeowners who want an en-suite master bedroom
- Growing families
New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.
Will the council need to approve it?
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.
Homes in conservation areas, areas of townscape character and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
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.
Working in Belfast
We cover Belfast and the postcode districts BT1, BT2, BT6, BT7, BT12, BT13. Nearby, we also take on projects in Castlereagh (2 miles), Newtownabbey (4 miles), Lisburn (7 miles), Carrickfergus (10 miles).
For homes towards County Down, Newtownards is around 9 miles away. In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
How much does a bedroom extension cost in Belfast?
Prices below are for Belfast, using the Northern Ireland factor of ×0.86. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Belfast: £1,380 to £2,750 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £22,000 – £27,500 | £22,000 – £29,000 | £24,500 – £33,500 |
| Bedroom and en-suite 18 m² | £24,500 – £30,500 | £29,000 – £38,000 | £37,000 – £50,000 |
| Two rooms 30 m² | £41,000 – £50,500 | £49,000 – £63,500 | £61,500 – £83,000 |
Try the guide-price tool to see a range for your own size and finish.
Our process, step by step
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions people ask about bedroom extensions
Who do I contract with for a bedroom extension in Belfast?
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.
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 see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Belfast, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
Will a new bedroom need planning permission?
Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.
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.