Part single, part two-storey extensions in Bishop Auckland

What we'd confirm first for a project in Bishop Auckland.

Postcode districts: DL14 and DL15
County / area: County Durham, England
Price region: North East England
Guide price: £65,000–£89,000 (£1,800–£2,480 per m²)
Approval route: It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns: Shildon (2.2 miles), Spennymoor (4.2 miles), Newton Aycliffe (4.9 miles)
Distance to Darlington: about 10.4 miles
First visit: Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension suits you if you want a generous ground floor but only need one extra room upstairs, or if a full two-storey design would affect a neighbour too much. You get design options that test where the two-storey part works best, the approvals your nation needs, structural design, building regulations approval and the build, carried out by vetted teams working under S&K.

Bishop Auckland sits about 10.4 miles from Darlington. Closer to home, Shildon is 2.2 miles away and Spennymoor 4.2 miles.

What it costs in Bishop Auckland

Most of the cost of a part single, part two-storey extension is set by its size and specification. For Bishop Auckland and the rest of North East England, our guide is £1,800–£2,480 per m² including VAT, so about £65,000–£89,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

Spec	Per m²	A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential	£1,660–£2,280 per m²	£59,500–£82,000
Standard	£1,800–£2,480 per m²	£65,000–£89,000
Premium	£2,160–£2,970 per m²	£78,000–£107,000

Planning and building regulations in Bishop Auckland

In England, the extension can only be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with matching materials and roof pitch. We check the whole design against the rules, including the 50% garden coverage limit. If any part fails, or extends beyond a side wall on two floors, you need planning permission, costing £548 (or £575 for applications made from 8 December 2026).

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 Bishop Auckland homes

The roof junction

Where the single-storey roof meets the two-storey wall you need a sound weathering detail, usually a lead or similar flashing, and enough height for roof lights or a lantern. We set the roof falls and the upstairs window sill heights together so they do not clash.

Structure at the step

The first-floor wall above often sits over the new open-plan space, so it needs a steel beam or frame to carry it. Loads come down at different points than in a full two-storey design, and the engineer sizes the foundations to suit each part.

How we'd run your project

Understand the brief
At your home in Bishop Auckland we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
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 part single, part two-storey extensions in Bishop Auckland

How much does a part single, part two-storey extension cost in Bishop Auckland?

Our guide for North East England, which covers Bishop Auckland, is £1,800–£2,480 per m² including VAT. A typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) comes to about £65,000–£89,000. 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 part single, part two-storey extension in Bishop Auckland?

Bishop Auckland is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How long does a part single, part two-storey 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.

Which side should the two-storey part go on?

Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.

Can the single-storey part be deeper than the two-storey part?

With planning permission, yes, and that is often the point of the design: the ground floor projects further into the garden while the first floor stays back from neighbours. Under permitted development, the depth limits for extensions of more than one storey can apply to the whole extension, so we confirm which route applies before drawings are finalised.

Nearby

Nearby towns we cover for part single, part two-storey extensions:

Other extensions in Bishop Auckland

All two-storey extension services in Bishop Auckland · Part single, part two-storey extensions across County Durham

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.