A garden room is a great way to add a valuable extra room to a flat. You will, though, always need Planning Permission to build a garden room in the garden of a flat.
Planning Permission Guides
This archive of articles looks at the planning rules you need to consider when building a garden room. In many cases, you can build a garden room under the Permitted Development rules without a full planning application. You do need to assertain your situation before work starts, as in the worst case senario you would have to dismantle your building! Your garden room supplier will be able to advise on your specific situation and may make any application on your behalf as part of their overall project.
What’s the Planning Permission position when building a granny annexe in your garden. The Log Cabin Home have produced a detailed article which answers some of the key questions you should ask.