Ballymena double-storey extensions, designed and built
Ballymena homeowners can use us for the whole double-storey extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in BallymenaFrom £32,500 inc VAT
- PlanningUsually needs planning permission
- Build time16–24 weeks on site
- Postcode districtsBT42, BT43
Extensions in and around Ballymena
Postcode districts we cover around Ballymena include BT42, BT43. The same team covers Antrim (10 miles), Larne (18 miles), Newtownabbey (20 miles), Carrickfergus (21 miles), all within easy reach.
In Northern Ireland, extension projects follow the NI planning rules and council building control, which we account for from the first survey.
Planning rules that apply in Ballymena
In Northern Ireland the Planning (General Permitted Development) Order 2015 lets some single-storey rear extensions go ahead without planning permission, up to 3 m on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Larger, side and two-storey extensions normally need planning permission from the council, and building control approval is separate.
The planning position for a specific Ballymena address depends on its history and any designations, which is why we check it at the first visit.
Northern Ireland has no Party Wall Act. Where work is on or close to a shared boundary, we agree access and protection with your neighbour in writing before work starts.
Applications are decided by your council, which handles local planning in Northern Ireland.
When a double-storey extension makes sense
- Homeowners who would otherwise consider moving
- Growing families who need a bedroom as well as a bigger kitchen
- Houses with enough distance to the rear or side boundary
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Double-storey extension prices in Ballymena
These guide figures apply our Northern Ireland adjustment (×0.86) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Ballymena: £1,330 to £2,580 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £32,500 – £39,500 | £37,000 – £49,000 | £47,000 – £62,000 |
| 4 m × 4 m, two floors 32 m² | £42,500 – £51,000 | £49,500 – £65,000 | £63,000 – £83,000 |
| 4 m × 6 m, two floors 48 m² | £63,500 – £76,500 | £74,000 – £97,500 | £94,500 – £124,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Double-storey extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Ballymena, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Ballymena be involved?
If a planning application is needed, the council notifies neighbours. Where work is close to a shared boundary, we agree access and protection with them in writing.
Who do I contract with for a double-storey extension in Ballymena?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,330 to £2,580 per m² of new floor area including VAT, compared with £1,500 to £2,920 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Ballymena
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.