Do You Need Planning Permission for Decking? (UK Rules)

Decking is one of the most common garden jobs and one of the most commonly misunderstood. The good news is that most of it needs no planning permission at all. The bad news is that the exceptions catch people out, usually on sloping gardens. Here's the rule, the exceptions, and what to do about them.

The rule: permitted development, with three tests

In England, decking is treated as an outbuilding or garden structure under permitted development. You don't need planning permission if all three of these are true:

1. Height. No part of the deck is more than 30cm above the ground. That's measured from the natural ground level directly beneath it, at the lowest point.
2. Coverage. The deck, together with every other extension, outbuilding and hard structure in the garden, covers no more than 50% of the land around the original house. "Original" means as it was first built or as it stood in 1948, so earlier extensions count against you.
3. Position. It's not in front of the principal elevation, which usually means not in the front garden facing the road.

Wales has its own version of the permitted development rules. The height and coverage principles are similar, but check the Welsh Government guidance or ask us if you're in Wales.

The exceptions

• Raised decking. Anything over 30cm is a raised platform and needs planning permission. This is where sloping gardens go wrong: a deck that's level with the patio doors can be 60cm off the ground at the far end.
• Listed buildings. Decking within the curtilage of a listed building needs planning permission regardless of height, and may need listed building consent too.
• Designated land. Conservation areas, National Parks, Areas of Outstanding Natural Beauty and the Broads keep most of the rules but remove some, particularly for structures to the side of the house. Councils can also use Article 4 directions to withdraw permitted development rights in specific streets.
• Removed rights. Newer estates sometimes have permitted development rights removed as a condition of the original planning permission. Your decision notice, or the council's planning portal, will tell you.
• Flats and maisonettes have no permitted development rights for garden structures.

Building regulations

Decking is exempt from building regulations in almost every domestic case. The two situations where it's worth a conversation with building control are a deck high enough to need planning permission (where structure and guarding matter) and a deck that carries something else, such as a garden room or hot tub.

What to do about a raised deck

If your garden slopes and you want a level deck, you have three options:

• Terrace it. Two or more levels, each under 30cm, with steps between.
• Cut and fill. Lower the ground at the high end so the deck sits within 30cm of it everywhere.
• Apply for planning permission. A householder application is straightforward. Councils mostly care about overlooking, so screening and a sensible set-back from the boundary do most of the work.

If you're already building an extension, it's cheaper to include the decking in that application than to apply separately later.

Check before you build

The planning checker gives a quick first answer for your project and your council, and the local authority finder tells you who decides. If the deck is part of a bigger plan, a free call is the simplest way to find out what else it touches.