Side extensions in Sittingbourne: design, approvals and build
Sittingbourne homeowners can use us for the whole side extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in SittingbourneFrom £24,500 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsME9, ME10
Is a side extension right for your house?
- Homes needing a utility, study or ground-floor bedroom
- Houses where the rear garden is small
- Detached and semi-detached houses with side land
Covering Sittingbourne
Postcode districts we cover around Sittingbourne include ME9, ME10. Nearby, we also take on projects in Faversham (7 miles), Gillingham (9 miles), Chatham (9 miles), Rochester (10 miles).
In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
What should I budget for a side extension in Sittingbourne?
Labour and material costs vary across the UK, so for Sittingbourne we use our South East England factor (×1.12). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Sittingbourne: £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 |
Want a range for your exact size? The guide-price tool takes about a minute.
Planning rules that apply in Sittingbourne
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.
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 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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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.
Side extension questions answered
Do I need building regulations approval in Sittingbourne?
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 Sittingbourne, 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 long does a side extension take to build in Sittingbourne?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 weeks design and approvals.
How close to the boundary can I build?
It depends on height. In England, within 2 m of a boundary the eaves must not exceed 3 m under permitted development. Building on the boundary is possible but brings party wall and maintenance access issues we plan for.
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 Sittingbourne.
Book a free site visit in Sittingbourne
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.