house-extension.uk

Planning permission for extensions across Thame

Need planning permission for extensions in Thame? We survey the house, prepare what the council needs and deal with the officers until a decision is made.

  • Guide price in ThameFrom £350 inc VAT
  • PlanningWe find the right route for you
  • Timescale8–13 weeks typical decision period
  • Postcode districtsOX9
Homeowners reviewing extension elevation drawings and a 3D view on a tablet

Planning rules that apply in Thame

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 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).

Who this service is for

  • Homeowners who would rather not deal with the council themselves
  • Projects in conservation areas or with previous refusals
  • Anyone unsure whether their extension needs permission

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.

Extensions in and around Thame

Site visits are available across Thame (OX9). The same team covers Oxford (12 miles), Bicester (13 miles), Henley-on-Thames (14 miles), Abingdon (14 miles), all within easy reach.

Just over the Buckinghamshire border, Aylesbury is about 9 miles away. 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.

Fees in Thame

Guide fees for Thame including VAT, using our South East England factor of ×1.12. Council and building control charges are not included.

OptionWhat it coversGuide price
EssentialPermitted development confirmed in writing (certificate or notification)£350 – £750
StandardHouseholder planning application handled£650 – £1,250
PremiumApplication with heritage or design statements, and responses to the council£1,000 – £1,800

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.

Try the guide-price tool to see a range for your own size and finish.

How the project works

Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.

  1. Free site visit

    First, a site visit: we look at the house, garden, access and drains and listen to what you need.

  2. Design and approvals

    We draw the design, agree it with you and handle planning or permitted development checks and building regulations.

  3. Fixed written price

    With the design and specification agreed, you get a fixed written price and a start date.

  4. Build and sign-off

    The build is managed from start to finish, inspected at each stage and signed off on completion.

Common questions in Thame

Do you cover all of Thame?

Yes. We cover Thame and the surrounding parts of Oxfordshire. Site visits are free and there is no obligation.

Will my neighbours in Thame 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.

How long does this take for a Thame 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 Thame

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

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