Magherafelt, County Londonderry
Semi-detached rear extension in Magherafelt
We plan and build rear extensions for semi-detached houses for homeowners in Magherafelt. Single or two-storey extensions for semi-detached houses, with side access and one party wall. Start with a free site visit, then a written price once the design is agreed.
Magherafelt is covered from our County Londonderry round, including BT45. Semi-detached houses are common across County Londonderry, and their side access makes rear extensions quicker to build.
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 semi-detached rear extension cost in Magherafelt?
For Magherafelt we work from the Northern Ireland rate: £1,650–£2,700 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 wide × 4 m deep (12 m²) | £20,000–£32,500 |
| 4 m wide × 5 m deep (20 m²) | £33,000–£54,000 |
| 4 m wide × 6 m deep (24 m²) | £39,500–£64,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a semi-detached rear extension in Magherafelt?
Whether your semi-detached rear extension in Magherafelt needs a planning application depends on its size, your house and any local restrictions.
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.
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.
Northern Ireland has no larger-extension prior approval route; anything beyond permitted development needs a planning application.
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 Magherafelt like to extend?
Semis and detached houses are typical of Magherafelt, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a semi-detached rear extension in Magherafelt 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
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.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Semi-detached rear extensions near Magherafelt
Neighbouring places we cover include Cookstown (9.4 miles) and Coalisland (15.1 miles).
- Semi-detached rear extension in Cookstown
- Semi-detached rear extension in Coalisland
- Semi-detached rear extension in Ballymena
- Semi-detached rear extension in Antrim
- Semi-detached rear extension in Dungannon
Other work in Magherafelt:
FAQ
Semi-detached rear extension questions in Magherafelt
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.
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.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
Do you handle building control in Magherafelt?
Yes. We apply to the council's building control team and hand over the completion certificate.
What postcode areas do you cover around Magherafelt?
Including BT45, and the surrounding County Londonderry area.
Is the site visit in Magherafelt free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.