Donaghadee · County Down

Two-storey side extensions in Donaghadee

A two-storey side extension is one of the most space-efficient ways to add bedrooms and living space to a house in Donaghadee, because the new floors share one set of foundations and one roof.

What we'd confirm first for a project in Donaghadee.

Postcode districts
BT21
County / area
County Down, 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
Bangor (County Down) (5.5 miles), Newtownards (7.1 miles), Comber (10.5 miles)
Distance to Bangor (County Down)
about 5.4 miles
First visit
Free, no obligation

About a two-storey side extension

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.

We cover Donaghadee (BT21) and the places around it, including Bangor (County Down) (5.5 miles), Newtownards (7.1 miles) and Comber.

What it costs in Donaghadee

Expect a two-storey side extension in Donaghadee to land somewhere around £76,000–£101,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Our Northern Ireland guide rate is £1,800–£2,420 per m², including VAT. 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 Donaghadee

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 Donaghadee homes

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.

Matching the ridge and roof

A hipped house usually needs a hipped extension roof, and a gabled house a gable. Matching the pitch, tiles, ridge detail and brick bond is what makes a side extension look original rather than added, and councils look closely at it on a front-facing addition.

How we'd run your project

  1. Measure and listen

    A visit to Donaghadee to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Drawings, then consent

    We draw the scheme, check it against the rules in Northern Ireland, and take it through the right consent with the council.

  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. 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 Donaghadee

Which postcodes do you cover around Donaghadee?

We cover Donaghadee (BT21) and nearby places including Bangor (County Down), Newtownards and Comber, plus the rest of County Down. The first site visit is free.

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 Donaghadee?

Our guide for Northern Ireland, which covers Donaghadee, 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.

Do I need planning permission for a two-storey side extension in Donaghadee?

Donaghadee 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.

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

Close to Donaghadee? We work across the area, including:

Other extensions in Donaghadee

All two-storey extension services in Donaghadee · Two-storey side extensions 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.

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