Comber · County Down

Two-storey extensions for detached houses in Comber

Homes in Comber with a bit of space to the side or rear can often take a two-storey extension for a detached house. We'll tell you honestly whether yours can, and what approvals it needs.

Before you start in Comber, here's what applies.

Postcode districts
BT23
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 (3.7 miles), Dundonald (3.7 miles), Castlereagh (5.9 miles)
Distance to Bangor (County Down)
about 8.3 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.

Around Comber we also work in Newtownards, Dundonald and Castlereagh, and across the rest of County Down. Postcode district in and near Comber: BT23.

What it costs in Comber

A guide price for Comber: around £76,000–£101,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). That works out at £1,800–£2,420 per m² of new floor space, including VAT at 20%. 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 Comber

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 Comber 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.

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

  1. Look at the house

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

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Comber.

  3. Price it properly

    Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.

  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 Comber

Who handles building control for a project in Comber?

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.

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

Comber 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 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

Other towns near Comber:

Other extensions in Comber

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

The quickest next step is a visit. We'll look at your house in Comber and give you an honest view of the options.

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