Derry~Londonderry, County Londonderry
Semi-detached rear extension in Derry~Londonderry
For homes in Derry~Londonderry, a semi-detached rear extension is often the simplest way to gain space without moving. Single or two-storey extensions for semi-detached houses, with side access and one party wall. We take it from survey to completion certificate.
We cover Derry~Londonderry (BT48) as part of our County Londonderry work. In Derry~Londonderry 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 Derry~Londonderry?
A semi-detached rear extension in Derry~Londonderry is priced at £1,650–£2,700 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 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in Derry~Londonderry?
Planning for a semi-detached rear extension in Derry~Londonderry follows the Northern Irish householder rules.
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. At the first visit we measure what is there now and tell you which route fits: permitted development or a planning application.
What are homes in Derry~Londonderry like to extend?
Semis and detached houses are typical of Derry~Londonderry, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a semi-detached rear extension in Derry~Londonderry 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.
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.
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.
Semi-detached rear extensions near Derry~Londonderry
Close by, we work in Strabane, about 13.6 miles away, and Limavady, about 14.7 miles away.
- Semi-detached rear extension in Strabane
- Semi-detached rear extension in Limavady
- Semi-detached rear extension in Portstewart
- Semi-detached rear extension in Coleraine
- Semi-detached rear extension in Omagh
Other work in Derry~Londonderry:
FAQ
Semi-detached rear extension questions in Derry~Londonderry
What postcode areas do you cover around Derry~Londonderry?
Including BT48, and the surrounding County Londonderry area.
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.
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.
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.
Do you handle building control in Derry~Londonderry?
Yes. We apply to the council's building control team and hand over the completion certificate.
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.