Two-storey side extensions in Newton Aycliffe

What we'd confirm first for a project in Newton Aycliffe.

Postcode districts: DL5
County / area: County Durham, England
Price region: North East England
Guide price: £77,500–£104,000 (£1,840–£2,480 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Shildon (3 miles), Ferryhill (4.6 miles), Bishop Auckland (4.9 miles)
Distance to Darlington: about 6.6 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 postcode district DL5 in and around Newton Aycliffe, along with neighbouring Shildon, Ferryhill and Bishop Auckland.

What it costs in Newton Aycliffe

In North East England, which includes Newton Aycliffe, we'd expect a two-storey side extension to cost around £77,500–£104,000 for a 3 m × 7 m footprint on two floors (42 m² of new floor space), or £1,840–£2,480 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.

Spec	Per m²	A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential	£1,700–£2,280 per m²	£71,500–£95,500
Standard	£1,840–£2,480 per m²	£77,500–£104,000
Premium	£2,210–£2,970 per m²	£93,000–£124,500

Planning and building regulations in Newton Aycliffe

In England, a two-storey side extension always needs householder planning permission, because permitted development only allows single-storey extensions beyond a side wall. The fee is £548 (or £575 for applications made from 8 December 2026), and councils should decide within 8 weeks of validation. Expect them to look at set-back, roof height, gaps to the boundary and the effect on neighbours.

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Newton Aycliffe homes

Avoiding a terracing effect

Where semi-detached houses sit close together, side extensions on neighbouring houses can join up and turn a row of pairs into a terrace. Many councils ask for a gap to the boundary at first floor to stop this, so we check local guidance before fixing the width.

Side windows, boundaries and gutters

Upstairs windows in the side wall face the neighbour, so they are usually obscure-glazed and fixed, or left out. Building close to the boundary also raises questions about foundations, overhanging gutters and access for maintenance, so we design the eaves and gutter to stay within your land.

How we'd run your project

Free site visit
We visit your home in Newton Aycliffe, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
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.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about two-storey side extensions in Newton Aycliffe

Which postcodes do you cover around Newton Aycliffe?

We cover Newton Aycliffe (DL5) and nearby places including Shildon, Ferryhill and Bishop Auckland, plus the rest of County Durham. The first site visit is free.

How much does a two-storey side extension cost in Newton Aycliffe?

Our guide for North East England, which covers Newton Aycliffe, is £1,840–£2,480 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 £77,500–£104,000. 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 side extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), 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.

Who handles building regulations for a project in Newton Aycliffe?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

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

The same service in neighbouring towns:

Other extensions in Newton Aycliffe

All two-storey extension services in Newton Aycliffe · Two-storey side extensions across County Durham

Want a figure first? Try our guide price tool, then book a free visit to firm it up.