Rotherham annexe extensions, designed and built
We design and build annexe extensions for houses in Rotherham, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in RotherhamFrom £51,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsS5, S9, S60, S61, S62
Local to Rotherham
Site visits are available across Rotherham (S5, S9, S60, S61, S62, S65). Neighbouring towns we cover include Rawmarsh (2 miles), Sheffield (6 miles), Dinnington (8 miles), Barnsley (10 miles).
For homes towards Derbyshire, Dronfield is around 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.
When an annexe extension makes sense
- Multi-generational families
- Homes with a large side or rear garden
- Relatives who need support close by
Accessibility is cheaper to design in than to retrofit. Level access, a 900 mm door width, a level-access shower and space to turn a wheelchair can all be planned into the footprint for little extra cost.
Will the council need to approve it?
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Guide prices for Rotherham
These guide figures apply our Yorkshire and the Humber adjustment (×0.94) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Rotherham: £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 |
Want a range for your exact size? The guide-price tool takes about a minute.
Our process, step by step
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 Rotherham home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Rotherham
Do you cover all of Rotherham?
Yes. We cover Rotherham and the surrounding parts of South Yorkshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Rotherham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Rotherham, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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 Rotherham.
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.
Book a free site visit in Rotherham
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.