The good news is that around 95% of our garden entertainment rooms don't need any form of planning permission at all — they can simply be built under your permitted development rights. There are just a few straightforward rules to keep in mind: the building needs to be under 2.5m high, take up no more than half of your garden, and be used for something incidental to your main house, like a games room, cinema room or bar rather than as separate living accommodation. Most of our entertainment room builds also come in comfortably under 30sqm, which helps keep them well within the guidelines.