Castlereagh, County Down
Two-storey rear extension in Castlereagh
We plan and build two-storey rear extensions for homeowners in Castlereagh. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Start with a free site visit, then a written price once the design is agreed.
We cover Castlereagh (BT8) as part of our County Down work. In Castlereagh, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Castlereagh?
For Castlereagh we work from the Northern Ireland rate: £1,570–£2,350 per square metre of new floor, including VAT, 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a two-storey rear extension in Castlereagh?
Here is how the rules in Northern Ireland apply to a two-storey rear extension in Castlereagh.
Northern Ireland's 2015 Order allows a two-storey rear extension of up to 3 metres where at least 7 metres is left to the rear boundary. Anything larger, or in a conservation area, needs a planning application to the council.
Conservation areas, Areas of Outstanding Natural Beauty and listed buildings restrict permitted development in Northern Ireland. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Castlereagh like to extend?
Semis and detached houses are typical of Castlereagh, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a two-storey rear extension in Castlereagh comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for council building control.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Two-storey rear extensions near Castlereagh
We also build two-storey rear extensions in nearby Belfast (2.3 miles) and Dundonald (3.7 miles).
- Two-storey rear extension in Belfast
- Two-storey rear extension in Dundonald
- Two-storey rear extension in Holywood
- Two-storey rear extension in Newtownabbey
- Two-storey rear extension in Lisburn
Other work in Castlereagh:
FAQ
Two-storey rear extension questions in Castlereagh
Can you match the brick or stone on my Castlereagh house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do I need planning permission for a rear extension in Castlereagh?
Often not for a single-storey rear extension of up to 3 metres (4 metres detached) under Northern Ireland's permitted development rules, outside conservation areas.
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.
Do you handle building control in Castlereagh?
Yes. We apply to the council's building control team and hand over the completion certificate.
Do I need a party wall agreement?
Northern Ireland has no Party Wall Act; we agree any shared-wall work with your neighbour in writing.
Is the site visit in Castlereagh free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.