Decking is one of those projects that feels like it should be simple. Usually it is. But raise it above 30cm — which many people do on sloping gardens without thinking about it — and you've crossed into planning permission territory.
No, if the decking is under 30cm high and covers less than 50% of the garden. Yes, if it\'s higher, in a conservation area, or in front of the house.
Decking is permitted development where it is no more than 30cm above ground level at any point, is not positioned forward of the principal elevation of the house, combined with other outbuildings and extensions does not cover more than 50% of the garden, and the property is not listed or in a conservation area.
On a level garden, 30cm is straightforward. On a sloping garden, decking that starts at ground level at the house end may be substantially higher than 30cm at the garden end. Height is measured at the highest point. This catches a large proportion of decking enforcement cases — and it\'s the trap that most garden designers don\'t flag.
Decking footprint counts toward total garden coverage alongside house extensions and outbuildings. The 50% limit is cumulative across everything, not just the decking you\'re about to build.
A decking area attached to a garden room or outbuilding must comply with Class E restrictions, which explicitly state it cannot include a raised platform over 30cm. This applies even if the decking would be under 30cm as a standalone structure.
Standard searches check the public register. We go further — querying live portals, blocked legacy systems, pre-merger authority databases, committee PDF archives, Land Registry title constraints, and comparable decisions across your postcode cluster. What we retrieve determines what you know before you build, buy, or appeal.