Dinnington annexe extensions, designed and built
Dinnington homeowners can use us for the whole annexe extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in DinningtonFrom £51,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsS25

Is an annexe extension right for your house?
- Homes with a large side or rear garden
- Relatives who need support close by
- Multi-generational families
What should I budget for an annexe extension in Dinnington?
Prices below are for Dinnington, using the Yorkshire and the Humber factor of ×0.94. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Dinnington: £1,880 to £3,570 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £51,500 – £65,000 | £56,000 – £70,500 | £70,500 – £89,500 |
| One-bedroom annexe 35 m² | £65,500 – £82,500 | £78,500 – £99,000 | £98,500 – £125,500 |
| Larger annexe 45 m² | £84,500 – £106,000 | £101,500 – £127,000 | £126,500 – £161,000 |
Try the guide-price tool to see a range for your own size and finish.
Extensions in and around Dinnington
Site visits are available across Dinnington (S25). Nearby, we also take on projects in Rotherham (8 miles), Rawmarsh (9 miles), Sheffield (11 miles), Doncaster (11 miles).
Homes across Yorkshire and the Humber range from back-to-back and through terraces to large suburban semis, and extension options vary with them.
Planning and approvals in Dinnington
In England an annexe that stays part of the household and connects to the house is assessed as an extension, but its size usually takes it beyond permitted development, so a householder application describing the ancillary use is the normal route.
The planning position for a specific Dinnington address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
What happens next
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
We visit your Dinnington home, measure up, talk through what you want and check the planning position.
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Annexe extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Dinnington, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Dinnington be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How long does an annexe extension take to build in Dinnington?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Does an annexe extension need planning permission?
Usually yes, because of its size and the way it will be used. Councils check that it stays ancillary to the main house, so the application must describe the use clearly.
How much does an annexe extension cost?
Our guide range is about £1,880 to £3,570 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £78,500 to £99,000 at standard spec in Dinnington.
Book a free site visit in Dinnington
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.