Garden Decking – do you need planning permission?
The answer is yes, no or maybe! Quite simply decking could be permitted development, but in some circumstances it will breach the conditions. So read on to ensure that you comply with PD rights as far as decking is concerned.
It might not be as simple as you initially thought!
Decking at the rear of a house
The Government’s technical guidance states that decking comes under Class E of Part 1 as an outbuilding. But this needs to be read in context. This and the GPDO states that it may not be higher than 0.3m as otherwise it would be classed as a raised platform.
The general consensus is that this comes under Class E as an outbuilding, however at least one appeal inspector has ruled that as it is attached to the building it actually comes under Class A as an extension.
It is our opinion that it is indeed classed as a rear or side extension if connected to the house. But once again Class A states that you cannot have a raised platform to this is still limited to 0.3m or 300mm.
Now if you have both Class A and Class E permitted development rights on your property, it should not affect you either way. It is still PD. The only time when it might have a bearing is if your decking extends beyond 3m from the rear wall on a semi or terraced house or 4m on a detached dwelling. If it does, we would recommend a certificate of lawfulness to confirm that it is PD. Planning Geek can assist you with this.
So why does Planning Geek think the Technical Guidance is wrong? We don’t. However the document is not binding, but at the same time, it simply says “Garden decking will therefore be permitted development under Class E subject to it not exceeding this 0.3m height limit and subject to the other limits and conditions under this Class.” But Class E is for outbuildings which are not attached to the main dwelling. In fact the technical guidance also says “Buildings which are attached to the house are not permitted under Class E (they would be subject to the rules in Class A).“
Decking at the rear is usually fixed to the rear wall. If it doesn’t touch the house, then it is Class E and if it does, it is Class A. Of course you will also find appeals that state it is Class E!
If decking is in the garden somewhere else, then yes it most certainly does come under Class E as an outbuilding.
Decking cannot be in front of the principal elevation, nor can it along with any other outbuilding or extension cover more than 50% of the land within the curtilage. In other words the front, side and rear gardens combined.
In a conservation area, the decking cannot be t the side of the property if it falls within Class A. A corner plot, would also limit decking to the rear only.
If Class A and Class E rights are removed, you will require planning permission for decking.
If you need clarification or further assistance, please reach out to us. We are here to help!
Height of the decking
Height is defined in the GPDO as
“Height” – references to height is the height measured from ground level. (Note, ground level is the surface of the ground immediately adjacent to the building in question, and would not include any addition laid on top of the ground such as decking. Where ground level is not uniform (for example if the ground is sloping), then the ground level is the highest part of the surface of the ground next to the building.)
Therefore it is quite possible that the decking could be under 0.3m where it meets the house and higher than this if the garden slopes away.
Decking attached to a home office or other outbuilding
This is acceptable, as long as the decking is not higher than 0.3m. Class E for outbuildings, which are incidental to the use of the dwelling, says it would not be allowed if ‘it would include the construction or provision of a verandah, balcony or raised platform;” The raised platform is over 0.3m or 300mm.
Page Updated: 17th January 2026
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