Single-storey rear extensions in Selby: design, approvals and build
Planning a single-storey extension in Selby? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in SelbyFrom £19,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsYO8

Planning and approvals in Selby
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
The planning position for a specific Selby address depends on its history and any designations, which is why we check it at the first visit.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
What should I budget for a single-storey extension in Selby?
For Selby we adjust our national guide rates by ×0.94, the factor we use for Yorkshire and the Humber. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Selby: £1,640 to £3,200 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,500 – £23,500 | £23,000 – £29,500 | £29,000 – £38,500 |
| 4 m × 5 m 20 m² | £32,500 – £39,000 | £38,500 – £49,000 | £48,500 – £64,000 |
| 5 m × 6 m 30 m² | £49,000 – £58,000 | £57,500 – £73,500 | £73,000 – £96,000 |
For a figure based on your own dimensions, use our guide-price tool.
When a single-storey extension makes sense
- Terraced houses that want a deeper kitchen across the full width
- Homeowners who want open-plan living onto the garden
- Semi-detached and detached houses with a usable rear garden
Depth is the big decision. Every extra metre adds floor area but also takes garden and can push you out of permitted development. We draw the room at two or three depths so you can see the trade-off in space, light and cost before anything is fixed.
Local to Selby
Across YO8, we can visit, measure and advise. Nearby, we also take on projects in York (12 miles), Harrogate (24 miles), Ripon (33 miles), Northallerton (42 miles).
Just over the East Riding of Yorkshire border, Goole is about 10 miles away. Homes across Yorkshire and the Humber range from back-to-back and through terraces to large suburban semis, and extension options vary with them.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about a single-storey extension in Selby
Who do I contract with for a single-storey extension in Selby?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does a single-storey extension take to build in Selby?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Do I need building regulations approval in Selby?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will I need a steel beam?
Almost always. Opening up the rear wall to join the new room to the house needs a beam, usually steel, sized by a structural engineer. It is included in our quotes.
Can I stay in the house during the build?
Usually yes. Most of the work happens outside until the final weeks, when we open the rear wall. We plan that stage carefully and seal the opening with a temporary screen to keep dust down.
Book a free site visit in Selby
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.