Two-storey rear extensions in Ballyclare
Adding a two-storey rear extension in Ballyclare gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in Northern Ireland.
Before you start in Ballyclare, here's what applies.
- Postcode districts
- BT39
- County / area
- County Antrim, Northern Ireland
- Price region
- Northern Ireland
- Guide price
- £49,500–£66,500 (£1,760–£2,380 per m²)
- Approval route
- It may be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary.
- Nearest towns
- Greenisland (6.1 miles), Jordanstown (6.1 miles), Newtownabbey (7.3 miles)
- Distance to Belfast
- about 11.1 miles
- First visit
- Free, no obligation
About a two-storey rear extension
A two-storey rear extension is a new two-floor addition built onto the back of your house, usually giving a larger kitchen or living space on the ground floor and one or two bedrooms or a bathroom above. Because both floors share one set of foundations and one roof, it adds a lot of floor space for the garden it uses. In some cases it can be built under permitted development, depending on where you live.
We cover Ballyclare (BT39) and the places around it, including Greenisland (6.1 miles), Jordanstown (6.1 miles) and Newtownabbey.
What it costs in Ballyclare
Expect a two-storey rear extension in Ballyclare to land somewhere around £49,500–£66,500 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Our Northern Ireland guide rate is £1,760–£2,380 per m², including VAT. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,620–£2,190 per m² | £45,500–£61,000 |
| Standard | £1,760–£2,380 per m² | £49,500–£66,500 |
| Premium | £2,110–£2,850 per m² | £59,000–£80,000 |
Planning and building control in Ballyclare
In Northern Ireland, a two-storey rear extension can be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with conditions on height, materials and roof pitch. Upper side windows within 15 m of a neighbouring boundary must be obscure-glazed and non-opening. Otherwise a planning application costs £347 per dwelling.
Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.
Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.
Design points for Ballyclare homes
Foundations and drains
Foundations for two storeys carry more load than a single storey and may need to go deeper near trees or on clay. Rear extensions often sit near drains, so we check sewer records early, as building over or near a public sewer may need the water company's agreement.
Depth and neighbours' light
Councils check that a two-storey rear extension does not take too much light or outlook from neighbouring windows, and many use a 45-degree line drawn from the nearest habitable window. We test this at sketch stage, so the depth you are shown is one that can realistically be approved.
How we'd run your project
Start at your house
We come to your home in Ballyclare, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Get it approved
Once you're happy with the design we submit it to the council for Ballyclare and deal with any questions from the planning officer.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.
Questions about two-storey rear extensions in Ballyclare
Who handles building control for a project in Ballyclare?
We handle it as part of the project. What's needed in Northern Ireland: building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
How much does a two-storey rear extension cost in Ballyclare?
Our guide for Northern Ireland, which covers Ballyclare, is £1,760–£2,380 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £49,500–£66,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Which postcodes do you cover around Ballyclare?
We cover Ballyclare (BT39) and nearby places including Greenisland, Jordanstown and Newtownabbey, plus the rest of County Antrim. The first site visit is free.
How long does a two-storey rear extension take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils aim to decide local applications within an average of 15 weeks; many take longer), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
Will a two-storey rear extension block my neighbour's light?
It can if it is too deep or too close to the boundary, which is why councils look closely at its effect on neighbouring windows and gardens. We test the design against light and outlook early, keep the first floor shorter or set in where needed, and use a hipped roof to reduce bulk on the boundary side.
Nearby
Other towns near Ballyclare:
Other extensions in Ballyclare
- Side
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Ballyclare · Two-storey rear extensions across County Antrim
Book a free site visit in Ballyclare and we'll tell you what's possible, what approvals you need and what the design stage would cost.