Building regulations for extensions across Sunbury-on-Thames
For Sunbury-on-Thames homeowners we handle building regulations for extensions, with fees agreed in writing before any work starts.
- Guide price in Sunbury-on-ThamesFrom £1,000 inc VAT
- Approval routeFull plans or building notice
- Timescale2–5 weeks for drawings
- Postcode districtsKT12, TW16, TW17
Working in Sunbury-on-Thames
Site visits are available across Sunbury-on-Thames (KT12, TW16, TW17). Neighbouring towns we cover include Walton-on-Thames (1 mile), West Molesey (2 miles), Ashford, Surrey (3 miles), Weybridge (3 miles).
Hampton, in Greater London, is roughly 2 miles from Sunbury-on-Thames and also on our list. 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 it costs in Sunbury-on-Thames
Fees below are our Sunbury-on-Thames guide (×1.12, the South East England factor), including VAT. Council and building control fees are extra.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Building regulations drawings for a simple single-storey extension | £1,000 – £2,050 |
| Standard | Drawings plus structural calculations | £1,450 – £2,950 |
| Premium | Complex or two-storey pack with energy calculations | £2,450 – £4,300 |
Our design fee only. Building control charges are set by your council (or, in England and Wales, a registered building control approver) and quoted separately.
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in Sunbury-on-Thames
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.
The planning position for a specific Sunbury-on-Thames 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.
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 is included
- Energy and glazing checks, including whole-house calculations if needed
- Submission to the council or a registered building control approver
- Completion certificate on sign-off
- Inspection bookings throughout the build
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Sunbury-on-Thames
Will my neighbours in Sunbury-on-Thames 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.
Who do I contract with in Sunbury-on-Thames?
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 this take for a Sunbury-on-Thames home?
2–5 weeks for drawings, depending on the council and the complexity of the project.
Full plans or building notice?
A full plans application gets the drawings checked before work starts, which we usually recommend for extensions. A building notice is quicker to submit but carries more risk if something needs changing on site.
Who are building control?
Either your local council’s building control team or a registered building control approver. Both inspect the work and issue the completion certificate.
Book a free site visit in Sunbury-on-Thames
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.