County Down
Rear extensions in Castlereagh
Rear extensions in Castlereagh: single-storey and two-storey extensions, side returns, wraparounds and glass-led designs, planned around semis and detached houses and the Northern Irish rules.
Castlereagh is in County Down, with postcode districts including BT8. The nearest places we also cover are Belfast (2.3 miles) and Dundonald (3.7 miles).
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Rear extensions we build in Castlereagh
- 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 bungalows
- Rear extension plans and planning applications
Also available across County Down:
- Rear extensions for detached houses
- 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
- Building Regulations for rear extensions
Rear extension prices in Castlereagh
Northern Ireland prices are the lowest in our range.
| Example | Guide inc VAT |
|---|---|
| Single-storey, 3 m × 4 m (12 m²) | £20,000–£32,500 |
| Single-storey, 4 m × 6 m (24 m²) | £39,500–£64,500 |
| Two-storey, 3 m × 5 m footprint (30 m²) | £47,000–£70,500 |
| Side return, about 14 m² | £28,000–£46,500 |
| Wraparound, about 25 m² | £48,000–£78,500 |
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.
Planning rules for Castlereagh
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.
Nearby towns
FAQ
Questions people ask
How much is a rear extension in Castlereagh?
A 3 m × 4 m single-storey rear extension is about £20,000–£32,500 including VAT at our Northern Ireland guide rates; the written price follows a survey.
Do I need planning permission 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.
Is the site visit in Castlereagh free?
Yes, with no obligation.
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.