How Long Does Planning Permission Last in the UK?

Life gets in the way of extensions. Finances change, a job moves, a baby arrives, and the approved drawings sit in a drawer. Then someone asks: is that permission still any good? Here's the rule, the exceptions, and what to do if you've run out of time.

The standard rule: three years

A full planning permission in England and Wales must be begun within three years of the date on the decision notice. That's the default condition the council attaches to almost every householder approval. The council can set a different period, so read your decision notice, but three years is what you'll nearly always find.

Two things people get wrong:

• It's three years to start, not to finish.
• It runs from the decision date, not from when you applied or when you received the letter.

What "begun" actually means

The permission is kept alive by a material operation carried out in accordance with the approved plans. The law lists what counts:

• any work of construction in the course of erecting a building,
• any work of demolition,
• digging a trench for the foundations,
• laying any underground main or pipe,
• any operation in the course of laying out or constructing a road,
• any change in the use of the land (for change-of-use permissions).

Clearing the garden, ordering a kitchen, or putting up site fencing does not count. Nor does a trench dug in the wrong place or to the wrong depth. If you're starting work specifically to preserve a permission, do it properly: foundations where the drawings show them, and discharge any conditions that have to be dealt with before work begins (these are called pre-commencement conditions). Starting without discharging those can mean the start wasn't lawful and the permission lapses anyway.

Keep evidence. Dated photographs and a builder's invoice for the trench are what you'll show a buyer's solicitor or the council years later.

Once started, it doesn't expire

A lawfully begun permission has no end date. You can build at your own pace. The one check on that is a completion notice: if a project sits half-built for years, the council can serve notice requiring it to be finished by a given date, after which the permission stops applying to any unfinished work. These are rare for house extensions, but a half-built shell that annoys the neighbours is exactly when they appear.

Outline permission is different

If you have outline permission (common for plots and new dwellings, rare for extensions), there are two clocks: reserved matters must be applied for within three years, and work must begin within two years of the final reserved-matters approval.

If the three years have passed

The permission has lapsed. There's no extension in England now; the temporary provisions that allowed extending old permissions have ended. You reapply. In practice:

• If nothing has changed on the site or in local policy, a resubmission of the same scheme usually succeeds.
• If policy has changed (new design guidance, a conservation area, Article 4 directions), the council can refuse something it previously approved. That's the real risk of letting a permission lapse.
• Application fees apply again.

Permitted development has no clock

Work that doesn't need planning permission (permitted development) has no expiry, because there's nothing to expire. But the rules that apply are the ones in force when you build, and councils can remove permitted development rights with an Article 4 direction. A Lawful Development Certificate is worth getting: it records that the work was permitted on the day it was certified, which protects you if the rules later tighten.

The short version

Situation	Time limit
Full planning permission	Start within 3 years of the decision
Outline permission	Reserved matters within 3 years, start within 2 years of approval
Permission already begun lawfully	No expiry (council can serve a completion notice)
Permission lapsed	Reapply; no extension available
Permitted development	No expiry; rules on the day you build apply

Note that building regulations have their own separate three-year rule, and a separate sign-off process. Our guide to how long you get to sign off an extension covers that side.

If you've got an approval nearing its deadline and aren't sure whether to start, reapply or let it go, that's a sensible thing to bring to a free Build, Wait or Move Call. We'll tell you honestly which it is.