Newtownards · County Down

Two-storey extensions for detached houses in Newtownards

Adding a two-storey extension for a detached house in Newtownards 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.

Useful details for planning a two-storey extension for a detached house in Newtownards.

Postcode districts
BT22
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
Comber (3.6 miles), Dundonald (4.3 miles), Bangor (County Down) (4.8 miles)
Distance to Bangor (County Down)
about 4.8 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.

Newtownards sits about 4.8 miles from Bangor (County Down). Closer to home, Comber is 3.6 miles away and Dundonald 4.3 miles.

What it costs in Newtownards

Most of the cost of a two-storey extension for a detached house is set by its size and specification. For Newtownards and the rest of Northern Ireland, our guide is £1,800–£2,420 per m² including VAT, so about £76,000–£101,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

SpecPer m²A 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 Newtownards

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 Newtownards homes

Keeping it subordinate

Large detached houses can take a large extension, but councils still expect it to look secondary to the main house. A lower ridge, a modest set-back at the front and matching materials keep the proportions right, even on a wide plot.

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.

How we'd run your project

  1. Look at the house

    We start in Newtownards with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.

  2. Design and approvals

    We draw the extension and check it against the rules for Northern Ireland, then apply for planning permission or a certificate of lawfulness, whichever fits.

  3. Fixed price in writing

    With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.

  4. Build and sign-off

    Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about two-storey extensions for detached houses in Newtownards

Do I need planning permission for a two-storey extension for a detached house in Newtownards?

Newtownards 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 Newtownards?

Our guide for Northern Ireland, which covers Newtownards, 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.

How long does a two-storey extension for a detached house 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.

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

Nearby towns we cover for two-storey extensions for detached houses:

Other extensions in Newtownards

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

Tell us about your house in Newtownards and we'll call you back to arrange a free, no-obligation visit.

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