Lisburn, County Antrim
Two-storey rear extension in Lisburn
For homes in Lisburn, a two-storey rear extension is often the simplest way to gain space without moving. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. We take it from survey to completion certificate.
Lisburn is covered from our County Antrim round, including BT17, BT27 and BT28. In County Antrim we check the neighbours' rear windows first, because the upper floor is where most two-storey schemes win or lose planning.
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 Lisburn?
A two-storey rear extension in Lisburn is priced at £1,570–£2,350 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 Lisburn?
Here is how the rules in Northern Ireland apply to a two-storey rear extension in Lisburn.
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. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Lisburn like to extend?
Lisburn has terraces near the centre, semis on the edges and many detached houses and bungalows in the surrounding countryside, where plots are often generous.
How a two-storey rear extension in Lisburn 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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check or planning application, then building control drawings to the Northern Ireland Technical Booklets and structural calculations, plus a written agreement with neighbours for any shared-wall work.
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 Lisburn
Neighbouring places we cover include Belfast (6.7 miles) and Castlereagh (7.0 miles).
- Two-storey rear extension in Belfast
- Two-storey rear extension in Castlereagh
- Two-storey rear extension in Dundonald
- Two-storey rear extension in Newtownabbey
- Two-storey rear extension in Holywood
Other work in Lisburn:
FAQ
Two-storey rear extension questions in Lisburn
What postcode areas do you cover around Lisburn?
Including BT17, BT27 and BT28, and the surrounding County Antrim area.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
What is the 45-degree rule?
Many councils check that a two-storey extension does not cross a 45-degree line drawn from the nearest habitable window of the neighbouring house. We test it at the first drawing.
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.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.