Decking and planning
What Is the 4-Year Rule for Decking?
The 4-year rule was the time limit councils in England had to take enforcement action against building work, including decking, that needed planning permission but did not have it. Since 25 April 2024 that limit is 10 years for new work. Here is what that means for your deck.
At a glance
The Rule in Four Points
Finished before 25 April 2024
The old 4-year rule still applies. If the council took no action within 4 years of the deck being substantially completed, it is normally immune from planning enforcement.
Finished on or after 25 April 2024
The council has 10 years from the date the deck was substantially completed to take enforcement action.
Most decks need no permission
Decking no more than 30cm above the ground is usually permitted development, within the limits on garden coverage and front gardens.
Building regulations are separate
A council can now serve a building regulations notice up to 10 years after the work is completed. This used to be 12 months.
Background
What the 4-Year Rule Was
If you build something that needs planning permission without getting it, your council can take enforcement action, which can mean having to alter or remove the work. The law puts a time limit on this.
For building work, the limit used to be 4 years from the date the work was substantially completed. After that, the work became immune from enforcement. A raised deck counts as building work, which is why this became known as the 4-year rule for decking.
The April 2024 change
Why It Is Now Usually 10 Years
The Levelling-up and Regeneration Act 2023 changed the time limits in England. From 25 April 2024, a single 10-year limit applies to all breaches of planning control.
The change is not backdated. If a deck that needed permission was substantially completed before 25 April 2024, the 4-year limit still applies to it. If it was completed on or after that date, the council has 10 years.
These changes apply in England. Wales has its own planning rules, so check with your council if you live there.
Before you build
Does Your Deck Need Planning Permission?
Most garden decks do not. In England, decking is permitted development and needs no planning application if it is no more than 30cm above the ground, if it and any other extensions and outbuildings cover no more than half of the garden, and if none of it is in front of the wall forming the front of the house.
Extra limits apply in places such as National Parks, conservation areas and the grounds of listed buildings, and the permitted development rules do not cover flats. A deck more than 30cm above the ground will normally need planning permission.
The time limits are not a reason to skip permission. A council can act at any point within the 4 or 10 years, and a deck built without permission can cause problems when you come to sell your home. If you are unsure, ask your local planning authority before work starts.
Proving it
Lawful Development Certificates
If a deck has passed its time limit, you can apply to your council for a Certificate of Lawfulness of Existing Use or Development. Once it is granted, the deck is treated in law as lawful, which helps if a buyer's solicitor asks about it.
It is up to you to show when the deck was finished, so keep dated photos, invoices and receipts. The council looks at the facts and dates, not at whether it likes the design.
Not an amnesty
When the Time Limit Does Not Protect You
If a breach has been deliberately concealed, the council can apply to the magistrates' court for a planning enforcement order, which allows it to take action after the normal time limit has passed.
Separate rules apply to listed buildings. If your home is listed, speak to your council before building anything in the garden.
Building regulations
Building Regulations Have Their Own Time Limit
Planning permission and building regulations are different things. The Planning Portal says building regulations should be assumed to apply to any deck that needs planning permission.
Since 1 October 2023 in England, a council can serve a notice requiring work that breaks the building regulations to be altered or removed up to 10 years after the work was completed. The limit used to be 12 months.
Sources
Where This Information Comes From
GOV.UK: Enforcement and appeals, key changes under the Levelling-up and Regeneration Act
Planning Portal: What is the 10 year rule for planning enforcement?
Planning Portal: Decking, planning permission
Planning Portal: Decking, building regulations
legislation.gov.uk: Town and Country Planning Act 1990, section 171B (time limits)
legislation.gov.uk: Town and Country Planning Act 1990, section 171BA (planning enforcement orders)
legislation.gov.uk: Town and Country Planning Act 1990, section 191 (certificates of lawfulness)
legislation.gov.uk: Building Act 1984, section 36 (removal or alteration of offending work)
This page is general information, not legal advice. Links open in a new tab. Last checked November 2026.
Planning a New Deck?
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