What does a planning application cost for an extension?
In England the householder planning application fee is £548 from 1 April 2026 — one flat fee, whatever the size of the extension. Apply online through the Planning Portal and you pay a further £91.02 on top; pay your council directly and you skip that part.
The short version
Most people expect the fee to scale with the job. It doesn’t. A householder application — the type you use to enlarge, improve or alter a house — carries a single fixed fee no matter whether you’re adding a small porch or a full wraparound. From 1 April 2026 that fee is £548, paid to your local planning authority.
Two things trip people up. First, the £548 buys you a decision, not a yes. If the council refuses, the money is gone. Second, if you apply through the Planning Portal (which is how most applications are submitted) you pay an extra service charge of £75.83 plus VAT — £91.02 in total — on top of the council fee. Some councils still take applications and payment directly, and if yours does, that’s £91 saved for the sake of a bit more paperwork.
And the cheapest planning route of all costs nothing: if your extension is permitted development, there is no application and no fee. Worth checking that first, before you reach for your card.
Planning fees for an extension, England 2026
| Route | Fee | What it’s for |
|---|---|---|
| Permitted development | £0 | No application needed — you build within the PD limits |
| Larger home extension prior approval | £249 | Single-storey rear extension deeper than standard PD (up to 8m detached, 6m semi/terrace) |
| Lawful Development Certificate (proposed) | £274 | Council confirms in writing that a planned PD extension is lawful |
| Lawful Development Certificate (existing) | £548 | Certifies something already built under PD — useful when you sell |
| Householder planning application | £548 | Full application when the extension is outside PD limits |
| Planning Portal service charge (online) | £91.02 | Added to any of the above if you apply online rather than direct to the council |
Statutory fees from the Planning Portal “Application Fees — England” schedule (V2026, effective 1 April 2026) and The Town and Country Planning (Fees for Applications) Regulations. The Planning Portal service charge is £75.83 + VAT.
When you pay less than £548 — or nothing
The full householder fee is the price of needing planning permission. Plenty of extensions don’t, and the cheaper routes are worth knowing before you commit.
If your extension sits inside the permitted development limits — single storey, at the rear, within the depth and height caps — you need no application at all. Many people in that position still spend £274 on a Lawful Development Certificate for the proposed work, because a certificate is the council confirming, on paper, that what you’re building is lawful. When you come to sell, a buyer’s solicitor will ask for exactly that. It’s half the price of a full application and it removes an argument years down the line.
Going deeper than standard PD but still single storey? The larger home extension prior approval route lets you build up to 8m from the rear wall (detached) or 6m (semi or terraced) for £249. The council doesn’t judge the design — it just notifies your neighbours and steps in only if they object. Cheaper than a full application, and usually quicker.
The fee is the small number
It’s easy to fixate on £548 because it’s the one figure with a clear label. In practice it’s rarely the largest cost of getting to the point of building. You’ll usually need drawings — existing and proposed plans, elevations, a site and location plan — and those cost more than the application itself for most jobs. A structural engineer, a party wall surveyor if you’re building near a boundary, and Building Regulations fees all sit on top and are separate from planning.
Building Regulations approval is not the same thing as planning permission, and it has its own fees paid to building control. Almost every extension needs it, including permitted development ones. For the cost of the build itself — the part that dwarfs every fee here — see what an extension costs and what moves the price.
What’s changing in December 2026
The £548 fee has risen fast. It was £258 until March 2025, jumped to £528 in April 2025, and was indexed to £548 in April 2026. Draft regulations laid before Parliament in July 2026 propose another rise: the householder fee would go up by around £27, to roughly £575, for applications made on or after 8 December 2026. Until those regulations are in force the fee is £548, so treat £575 as what’s coming rather than what you pay today. If your application straddles that date, the fee is set by when you submit.
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