Two-storey side extensions in Carrickfergus
Homes in Carrickfergus with a bit of space to the side or rear can often take a two-storey side extension. We'll tell you honestly whether yours can, and what approvals it needs.
Before you start in Carrickfergus, here's what applies.
- Postcode districts
- BT38
- County / area
- County Antrim, Northern Ireland
- Price region
- Northern Ireland
- Guide price
- £76,000–£101,500 (£1,800–£2,420 per m²)
- Approval route
- Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.
- Nearest towns
- Greenisland (2.9 miles), Jordanstown (4.4 miles), Holywood (5.4 miles)
- Distance to Belfast
- about 9.5 miles
- First visit
- Free, no obligation
About a two-storey side extension
A two-storey side extension suits a detached or semi-detached house with a side garden, driveway or garage wide enough to build on. You get a design that sits comfortably on the street, a planning application or permitted development check depending on your nation, structural design, building regulations approval and the build itself. We manage the whole process, and the work is carried out by vetted teams working under S&K.
We cover Carrickfergus (BT38) and the places around it, including Greenisland (2.9 miles), Jordanstown (4.4 miles) and Holywood.
What it costs in Carrickfergus
Guide prices for two-storey side extensions in Northern Ireland are around £1,800–£2,420 per m² of new floor space, including VAT. For a typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space), that's roughly £76,000–£101,500. Design fees, structural calculations and approval fees are separate and listed on our prices page.
| Spec | Per m² | A 3 m × 7 m footprint on two floors (42 m² of new floor space) |
|---|---|---|
| Essential | £1,660–£2,230 per m² | £69,500–£93,500 |
| Standard | £1,800–£2,420 per m² | £76,000–£101,500 |
| Premium | £2,160–£2,900 per m² | £91,000–£122,000 |
Planning and building control in Carrickfergus
In Northern Ireland, permitted development for two-storey work is set out for rear extensions, so a two-storey side extension normally needs a planning application. The fee is £347 per dwelling, and councils aim for an average of 15 weeks on local applications. You also need building control approval from the council under the Technical Booklets.
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 Carrickfergus homes
Access and services
Side extensions often cover the only route to the back garden, a gas meter, soil pipes or a drain run. We plan bin and bike access, move meters and pipes where needed and check drains early, because these items affect both cost and layout.
Set-down and set-back
Councils usually want a two-storey side extension to look subordinate to the house. Setting the front wall back from the main front and dropping the ridge slightly below the main roof helps it read as an addition, and is often expected in local design guidance.
How we'd run your project
Measure and listen
A visit to Carrickfergus to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about two-storey side extensions in Carrickfergus
Which postcodes do you cover around Carrickfergus?
We cover Carrickfergus (BT38) and nearby places including Greenisland, Jordanstown and Holywood, plus the rest of County Antrim. The first site visit is free.
Do I need planning permission for a two-storey side extension in Carrickfergus?
Carrickfergus is in Northern Ireland. Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.
How long does a two-storey side 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.
How much does a two-storey side extension cost in Carrickfergus?
Our guide for Northern Ireland, which covers Carrickfergus, is £1,800–£2,420 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £76,000–£101,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Can I build a two-storey side extension over my driveway?
Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.
Nearby
Other towns near Carrickfergus:
Other extensions in Carrickfergus
- Rear
- 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 Carrickfergus · Two-storey side extensions across County Antrim
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Carrickfergus.