Two-storey extensions for detached houses in Bangor (County Down)

Useful details for planning a two-storey extension for a detached house in Bangor (County Down).

Postcode districts: BT19 and BT20
County / area: County Down, Northern Ireland
Price region: Northern Ireland
Guide price: £76,000–£101,500 (£1,800–£2,420 per m²)
Approval route: Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); most others need planning permission.
Nearest towns: Newtownards (4.8 miles), Donaghadee (5.5 miles), Holywood (6.4 miles)
First visit: Free, no obligation

About a two-storey extension for a detached house

This service suits you if you own a detached house and want a substantial amount of extra space, whether a side extension over a drive, a rear extension into the garden or a wraparound. You get a survey of the whole plot, options that compare layouts and costs, the approvals your nation needs, structural design and the build, carried out by vetted teams working under S&K.

We cover Bangor (County Down) (BT19 and BT20) and the places around it, including Newtownards (4.8 miles), Donaghadee (5.5 miles) and Holywood.

What it costs in Bangor (County Down)

Using our Northern Ireland rates, a two-storey extension for a detached house with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £76,000–£101,500, including VAT. Bigger or more glazed designs cost more per m². 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 Bangor (County Down)

In Northern Ireland, a two-storey rear extension on a detached house can be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary, with height, materials and roof pitch conditions. Side and wraparound designs normally need a planning application, which 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 Bangor (County Down) homes

Larger spans and steelwork

Bigger extensions often mean wider openings and longer spans, which need more steel and sometimes a steel frame. The engineer designs these early, because the size of the steel affects ceiling heights, floor depths and the cost.

Choosing the best side

On a detached house you can often extend on either side or the rear. We look at orientation for daylight, where the stairs and landing are, the distance to each boundary, drains and trees, so the extension goes where it adds the most useful space.

How we'd run your project

Understand the brief
At your home in Bangor (County Down) we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
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 extensions for detached houses in Bangor (County Down)

Do I need planning permission for a two-storey extension for a detached house in Bangor (County Down)?

Bangor (County Down) is in Northern Ireland. Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); most others need planning permission.

How much does a two-storey extension for a detached house cost in Bangor (County Down)?

Our guide for Northern Ireland, which covers Bangor (County Down), 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.

Which postcodes do you cover around Bangor (County Down)?

We cover Bangor (County Down) (BT19 and BT20) and nearby places including Newtownards, Donaghadee and Holywood, plus the rest of County Down. The first site visit is free.

Can I extend a detached house on both sides?

Sometimes. With planning permission, a council may accept extensions on both sides if the house stays well proportioned and keeps gaps to the boundaries. It is more common to extend on one side and the rear, or with a wraparound. We look at the plot as a whole before suggesting more than one extension.

Is a detached house extension a better investment than moving?

It often costs less than the gap between your house and a larger one nearby, once property tax, legal fees and removal costs are counted, but that depends on your area. Extending also has limits: every street has a ceiling price. We give you build costs so you can compare them with local asking prices.

Nearby

Close to Bangor (County Down)? We work across the area, including:

Other extensions in Bangor (County Down)

All two-storey extension services in Bangor (County Down) · Two-storey extensions for detached houses across County Down

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.