When Do I Need Planning Permission For A Garden Room?

‪@newgardenroomcompany9676‬
There are two elements to Garden Rooms that you need to bear in mind.
The first one is about the dimensions of building - the physical dimensions; the height, the width, the proportion of the garden it covers. There's a lot of information online about that, but the most useful resource is the Planning Portal - you can go there and look up about the dimensions, but in headline terms, assuming you have your Permitted Development rights, aren't in a conservation area or a listed building etc, then you can cover up to 50% of the of the plot, minus the land of the house itself in outbuildings.
But there has to be a 'reasonably necessary' test, so you couldn't just cover everything in outbuildings and then sort of retrospectively invent a way to use those buildings.
You need to think about the building - whether it's really reasonably necessary.
The other side is the use. The 'use' is where it's important to understand two different words; one of them is 'incidental' and the other is 'ancillary'.
Incidental buildings are the ones that have permitted development rights. Ancillary always requires planning permission, so we're going to a little bit more detail on that.
Ancillary is something that's an extension of the house itself, where you would be doing an activity within the outbuilding that you would normally do in the house. For example, sleeping and cooking would be things that you would normally do in the house, and that would require planning permission.
But the incidental uses would be things like workshops, a swimming pool, a greenhouse or potting shed - all of those things would be incidental uses and wouldn't need planning permission.
So there's the two sides you need to always be mindful of; the dimensions, which you can find online quite easily, and then the use itself - and that's often the one that people fall foul of.
For example, there was a court case in 2021 where a personal trainer had erected an outbuilding to use as a gym initially, and over the lockdown periods he started taking on clients and having them doing running sessions at his house in the garden.
There was access through a separate alleyway at the back, and over time the use intensified. My point is that at some point a sort of material 'change of use' happened, where that became a place of business - not just an extension of his house. So the need for planning permission was engaged, and to cut a long story short, the case required planning permission, in this case it was refused because it was considered to be so intensive a use that it was harmful to the community of people around.
But there are plenty of examples where people can use an outbuilding.
For example, if you're a child minder. If you're running a child-minding business from home and looking after less than six children - which is in line with the national guidance - that outbuilding could be used as an extension of that, as long as you're not needing to bring on any staff, and then intensify the site over the threshold. That's unlikely to need applying permission.
So what I'm saying here is you shouldn't just make assumptions. You should always take professional advice and get in touch with the Council or a Planning Consultant who will be able to assist you in offering advice either formally or informally or assist you in a building a strategy to secure permission if it's required.
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For more information, see our other videos featuring Planning Consultant Mark Doodes.
Recorded February 2023. This content does not constitute formal advice from New Garden Room Company or Mark Doodes Planning.

[@dannymurphy1779]

Holiday letting, Air BnB is another example that people ofthen miss when it comes to planning permission.

[@neilforrest363]

Thanks for the info. What do I have to do if I want my garden room to be higher than the 2.5m limit and 800mm from rear and side boundaries? Will I need to apply for planning for this? Thanks again