Northern Ireland
Rear extensions in County Down
Rear extensions in County Down: we cover 8 towns including Bangor, Castlereagh and Newtownards, with design, approvals and the build under one contract.
What are homes in County Down like to extend?
County Down has terraces near the centre, semis on the edges and many detached houses and bungalows in the surrounding countryside, where plots are often generous.
Rear extension prices in County Down
Northern Ireland prices are the lowest in our range. Per square metre including VAT, standard specification:
| Extension | Per m² |
|---|---|
| Single-storey rear extension | £1,650–£2,700 |
| Two-storey (per m² across both floors) | £1,570–£2,350 |
| Side return | £2,000–£3,310 |
| Wraparound | £1,910–£3,130 |
| Glass-led | £2,440–£4,180 |
Planning and building rules in County Down
Northern Ireland's permitted development rules allow a single-storey rear extension of 3 metres on terraced and semi-detached houses and 4 metres on detached houses, with a 4 metre height limit. Listed buildings, conservation areas and houses with removed rights need planning permission from the council.
Northern Ireland has no larger-extension prior approval route; anything beyond permitted development needs a planning application.
Northern Ireland's building regulations are administered by council building control teams, who approve the plans or a building notice and inspect the work through to completion.
There is no Party Wall Act in Northern Ireland; we agree any work affecting a shared wall or boundary directly with the neighbour, in writing.
Conservation areas, Areas of Outstanding Natural Beauty and listed buildings restrict permitted development in Northern Ireland.
Rear extensions we build in County Down
- Kitchen-diner rear extensions
- Side return extensions
- Wraparound extensions
- Glazed and glass-box rear extensions
- Rear extensions for terraced houses
- Rear extensions for semi-detached houses
- Rear extensions for detached houses
- Rear extensions for bungalows
- Flat-roof rear extensions
- Pitched and lean-to roof rear extensions
- Knocking through to a rear extension
- Roof lanterns and rooflights for rear extensions
- Permitted development rear extensions
- Rear extension plans and planning applications
- Building Regulations for rear extensions
- Single-storey rear extensions
- Two-storey rear extensions
Towns and districts in County Down
The main places we cover in County Down include Bangor, Castlereagh and Newtownards, across postcode areas BT.
| Town | Postcode districts | Nearest town we also cover |
|---|---|---|
| Bangor | BT19, BT20 | Newtownards (4.8 miles) |
| Castlereagh | BT8 | Belfast (2.3 miles) |
| Newtownards | BT23 | Dundonald (4.3 miles) |
| Newry | BT35 | Banbridge (12.1 miles) |
| Banbridge | BT32 | Craigavon (7.9 miles) |
| Dundonald | BT16 | Holywood (3.4 miles) |
| Holywood | BT18 | Dundonald (3.4 miles) |
| Downpatrick | BT30 | Castlereagh (18.3 miles) |
Areas near County Down
FAQ
Questions people ask
How much does a rear extension cost in County Down?
As a guide, £1,650–£2,700 per square metre including VAT for a standard single-storey extension at Northern Ireland rates.
Do I need planning permission in County Down?
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.
Which towns in County Down do you cover?
8 towns and districts, including Bangor, Castlereagh and Newtownards.
Do you handle building control?
Yes. We apply to the council's building control team and hand over the completion certificate.