Northern Ireland
Rear extensions in County Antrim
Rear extensions in County Antrim: we cover 7 towns including Belfast, Lisburn and Newtownabbey, with design, approvals and the build under one contract.
What are homes in County Antrim like to extend?
Semis and detached houses are typical of County Antrim, and many have room for a rear extension within Northern Ireland's permitted development limits.
Rear extension prices in County Antrim
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 Antrim
In Northern Ireland the Planning (General Permitted Development) Order (Northern Ireland) 2015 allows a single-storey rear extension of up to 3 metres on an attached house or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary. Building control approval from the council is still required.
Northern Ireland has no larger-extension prior approval route; anything beyond permitted development needs a planning application.
In Northern Ireland building control is run by the councils. A rear extension needs approval (full plans or building notice) and is built to the Northern Ireland Technical Booklets.
Northern Ireland has no Party Wall Act. Shared-wall work relies on agreement with your neighbour and the general law, so we put access and protection arrangements in writing before starting.
Conservation areas, Areas of Outstanding Natural Beauty and listed buildings restrict permitted development in Northern Ireland.
Rear extensions we build in County Antrim
- Single-storey rear extensions
- Two-storey rear extensions
- 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
Towns and districts in County Antrim
The main places we cover in County Antrim include Belfast, Lisburn and Newtownabbey, across postcode areas BT.
| Town | Postcode districts | Nearest town we also cover |
|---|---|---|
| Belfast | BT3, BT5, BT7 | Castlereagh (2.3 miles) |
| Lisburn | BT17, BT27, BT28 | Belfast (6.7 miles) |
| Newtownabbey | BT36, BT37 | Holywood (3.7 miles) |
| Carrickfergus | BT38 | Holywood (5.4 miles) |
| Ballymena | BT42, BT43 | Antrim (10.4 miles) |
| Antrim | BT41 | Ballymena (10.4 miles) |
| Larne | BT40 | Carrickfergus (9.3 miles) |
Areas near County Antrim
FAQ
Questions people ask
How much does a rear extension cost in County Antrim?
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 Antrim?
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 Antrim do you cover?
7 towns and districts, including Belfast, Lisburn and Newtownabbey.
Do you handle building control?
Yes. We apply to the council's building control team and hand over the completion certificate.