Two-storey extensions for detached houses in Blaydon-on-Tyne

Useful details for planning a two-storey extension for a detached house in Blaydon-on-Tyne.

Postcode districts: NE21 and NE39
County / area: Tyne and Wear, England
Price region: North East England
Guide price: £77,500–£104,000 (£1,840–£2,480 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); a two-storey side extension needs planning permission.
Nearest towns: Whickham (2 miles), Newburn (2 miles), Newcastle upon Tyne (4 miles)
Distance to Newcastle upon Tyne: about 4 miles
First visit: Free, no obligation

About a two-storey extension for a detached house

A two-storey extension for a detached house is a two-floor addition to the side, rear or both of a house that stands on its own plot. Detached houses often have room on more than one side, so there is more choice of layout and fewer shared-wall issues. The design still needs to respect boundaries, neighbours' windows and the look of the house.

We cover postcode districts NE21 and NE39 in and around Blaydon-on-Tyne, along with neighbouring Whickham, Newburn and Newcastle upon Tyne.

What it costs in Blaydon-on-Tyne

In North East England, which includes Blaydon-on-Tyne, we'd expect a two-storey extension for a detached house 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. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

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 Blaydon-on-Tyne

In England, a two-storey rear extension on a detached house can be permitted development within 3 m of the original rear wall and at least 7 m from the rear boundary, with matching roof pitch and materials, outside protected areas. Any two-storey side or wraparound extension needs planning permission, costing £548 (or £575 for applications made from 8 December 2026), with a decision due within 8 weeks of validation.

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 Blaydon-on-Tyne 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.

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.

How we'd run your project

Visit and first ideas
One of our team visits your house in Blaydon-on-Tyne, checks the walls, roof and drains, and sketches out options with you.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about two-storey extensions for detached houses in Blaydon-on-Tyne

Which postcodes do you cover around Blaydon-on-Tyne?

We cover Blaydon-on-Tyne (NE21 and NE39) and nearby places including Whickham, Newburn and Newcastle upon Tyne, plus the rest of Tyne and Wear. The first site visit is free.

How much does a two-storey extension for a detached house cost in Blaydon-on-Tyne?

Our guide for North East England, which covers Blaydon-on-Tyne, 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.

Do I need planning permission for a two-storey extension for a detached house in Blaydon-on-Tyne?

Blaydon-on-Tyne is in England, so England planning rules apply. Depends on position: a two-storey rear extension may be permitted development (3 m deep, 7 m from the rear boundary); a two-storey side extension needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

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.

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.

Nearby

We also cover places near Blaydon-on-Tyne, including:

Other extensions in Blaydon-on-Tyne

All two-storey extension services in Blaydon-on-Tyne · Two-storey extensions for detached houses across Tyne and Wear

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