Planning permission for extensions across Keynsham
For Keynsham homeowners we handle planning permission for extensions, with fees agreed in writing before any work starts.
- Guide price in KeynshamFrom £350 inc VAT
- PlanningWe find the right route for you
- Timescale8–13 weeks typical decision period
- Postcode districtsBS31
Planning rules that apply in Keynsham
In England the main routes are permitted development (ideally confirmed with a lawful development certificate, £274), larger home extension prior approval (£249, 42 days) and a householder planning application (£548, normally 8 weeks), with council fees as set from 1 April 2026.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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).
Working in Keynsham
Across BS31, we can visit, measure and advise. Neighbouring towns we cover include Bath (6 miles), Nailsea (11 miles), Portishead (13 miles), Frome (15 miles).
South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
When it helps
- Projects in conservation areas or with previous refusals
- Anyone unsure whether their extension needs permission
- Homeowners who would rather not deal with the council themselves
A lawful development certificate is not compulsory for permitted development, but it is the cleanest proof that the extension was lawful when you come to sell. We usually recommend one.
What it costs in Keynsham
Guide fees for Keynsham including VAT, using our South West England factor of ×1.02. Council and building control charges are not included.
| Option | What it covers | Guide price |
|---|---|---|
| Essential | Permitted development confirmed in writing (certificate or notification) | £350 – £700 |
| Standard | Householder planning application handled | £600 – £1,150 |
| Premium | Application with heritage or design statements, and responses to the council | £900 – £1,650 |
Our handling fee only. Council fees are extra: in England from 1 April 2026 a householder application is £548, a lawful development certificate for a proposed extension £274 and a larger home extension prior approval £249. Drawings are priced separately.
For a figure based on your own dimensions, use our guide-price tool.
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
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
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.
Questions answered
Will my neighbours in Keynsham 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 you cover all of Keynsham?
Yes. We cover Keynsham and the surrounding parts of Somerset. Site visits are free and there is no obligation.
How long does this take for a Keynsham home?
8–13 weeks typical decision period, depending on the council and the complexity of the project.
How much does planning permission cost?
In England, from 1 April 2026 the council fee is £548 for a householder application, £274 for a lawful development certificate for a proposed extension and £249 for larger home extension prior approval. Our handling fee is separate.
What happens if planning is refused?
You can revise the design and reapply, or appeal. We read the officer’s report and tell you honestly which option has a better chance.
Book a free site visit in Keynsham
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.