Downpatrick, County Down
Semi-detached rear extension in Downpatrick
Single or two-storey extensions for semi-detached houses, with side access and one party wall. We design, get the approvals for and build rear extensions for semi-detached houses in Downpatrick and the surrounding area, with one contract from the first survey to building control sign-off.
We cover Downpatrick (BT30) as part of our County Down work. In Downpatrick 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 Downpatrick?
A semi-detached rear extension in Downpatrick 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 |
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 Downpatrick?
Whether your semi-detached rear extension in Downpatrick 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 Downpatrick like to extend?
Semis and detached houses are typical of Downpatrick, and many have room for a rear extension within Northern Ireland's permitted development limits.
How a semi-detached rear extension in Downpatrick 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning or permitted development, building control approval, structural design and neighbour agreements are all handled by us.
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 Downpatrick
From Downpatrick, the nearest places we also cover are Castlereagh (18.3 miles) and Newtownards (18.3 miles).
- Semi-detached rear extension in Castlereagh
- Semi-detached rear extension in Newtownards
- Semi-detached rear extension in Dundonald
- Semi-detached rear extension in Lisburn
- Semi-detached rear extension in Belfast
Other work in Downpatrick:
FAQ
Semi-detached rear extension questions in Downpatrick
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.
Can you match the brick or stone on my Downpatrick house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
How long does a rear extension take to build in Downpatrick?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
How much does a semi-detached rear extension cost in Downpatrick?
As a guide, £1,650–£2,700 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £20,000–£32,500 at that rate. Your written price follows the survey.
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.