Side extensions in Alton
A side extension in Alton starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in AltonFrom £24,500 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsGU34
Local to Alton
We cover Alton and the postcode districts GU34. Neighbouring towns we cover include Bordon (5 miles), Basingstoke (9 miles), Fleet (11 miles), Aldershot (11 miles).
Farnham, in Surrey, is roughly 9 miles from Alton and also on our list. Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Side extension prices in Alton
Labour and material costs vary across the UK, so for Alton we use our South East England factor (×1.12). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Alton: £1,960 to £3,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £24,500 – £30,000 | £27,500 – £36,000 | £34,500 – £46,000 |
| 3 m × 6 m 18 m² | £35,000 – £42,500 | £41,000 – £53,500 | £52,000 – £69,000 |
| 3 m × 8 m 24 m² | £47,000 – £56,500 | £55,000 – £71,500 | £69,500 – £91,500 |
Try the guide-price tool to see a range for your own size and finish.
When a side extension makes sense
- Homes needing a utility, study or ground-floor bedroom
- Detached and semi-detached houses with side land
- Houses where the rear garden is small
Will the council need to approve it?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
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 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).
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Side extension questions answered
Will my neighbours in Alton 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.
Do I need building regulations approval in Alton?
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 Alton, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Can I build a side extension without planning permission?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a planning application.
How much does a side extension cost?
Our guide range is about £1,960 to £3,810 per m² including VAT, depending on specification, so a standard 18 m² single-storey side extension lands around £41,000 to £53,500 in Alton.
Book a free site visit in Alton
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.