County Antrim
Two-storey rear extensions in County Antrim
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Rear extensions in County Antrim: we cover 7 towns including Belfast, Lisburn and Newtownabbey, with design, approvals and the build under one contract.
In Belfast, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted. Semis and detached houses are typical of County Antrim, and many have room for a rear extension within Northern Ireland's permitted development limits.
How much does a two-storey rear extension cost in County Antrim?
In County Antrim, our guide for a two-storey rear extension is £1,570–£2,350 per square metre including VAT for a standard specification. Northern Ireland prices are the lowest in our range.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £47,000–£70,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £75,000–£113,000 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission in County Antrim?
In Northern Ireland a rear extension of more than one storey can be permitted development if it projects no more than 3 metres and stays at least 7 metres from the rear boundary. Two-storey extensions in conservation areas, and most larger schemes, need planning permission from the council.
Conservation areas, Areas of Outstanding Natural Beauty and listed buildings restrict permitted development in Northern Ireland.
Where in County Antrim do we work?
FAQ
Questions people ask
Does a two-storey rear extension need planning permission?
Almost always. England and Northern Ireland allow 3 metres without an application only if at least 7 metres remains to the rear boundary; Wales and Scotland are similar or stricter.
Is two-storey cheaper per square metre than single-storey?
Usually yes, because the foundations and roof are shared across twice the floor area. The total cost is higher.
Can I add an en-suite upstairs?
Yes. We plan the soil pipe route early so the bathroom sits where drainage works without boxing through the room below.
Do you cover all of County Antrim?
We cover 7 towns and districts in County Antrim, including Belfast, Lisburn and Newtownabbey.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.