Ballymena, County Antrim
Semi-detached rear extension in Ballymena
Thinking about a semi-detached rear extension in Ballymena? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Ballymena sits in County Antrim, with postcode districts including BT42 and BT43. In Ballymena we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
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 Ballymena?
Guide prices for a semi-detached rear extension in Ballymena start from our Northern Ireland rate of £1,650–£2,700 per square metre, including VAT. 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 |
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 semi-detached rear extension in Ballymena?
Whether your semi-detached rear extension in Ballymena needs a planning application depends on its size, your house and any local restrictions.
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's 2015 Order allows a two-storey rear extension of up to 3 metres where at least 7 metres is left to the rear boundary. Anything larger, or in a conservation area, needs a planning application to 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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Ballymena like to extend?
Semis and detached houses are typical of Ballymena, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a semi-detached rear extension in Ballymena comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
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.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Ballymena
Neighbouring places we cover include Antrim (10.4 miles) and Magherafelt (15.2 miles).
- Semi-detached rear extension in Antrim
- Semi-detached rear extension in Magherafelt
- Semi-detached rear extension in Larne
- Semi-detached rear extension in Newtownabbey
- Semi-detached rear extension in Carrickfergus
Other work in Ballymena:
FAQ
Semi-detached rear extension questions in Ballymena
Do I need planning permission for a rear extension in Ballymena?
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.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
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.
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.
Do you handle building control in Ballymena?
Yes. We apply to the council's building control team and hand over the completion certificate.