In many cases you won’t need planning permission to build a garden room as they fall into Permitted Development, however if you live in a Listed Building, a National Park, a Site of Natural Beauty or a World Heritage site you will need to apply for Planning Permission to install a garden room.
The height of the garden room and where you plan to situate it in the garden are key issues in relation to Planning Permission and garden rooms.
Many garden rooms have an overall height of less than 2.5m; this means they can be sited within 2m of the boundary. This is useful in small gardens where space is at a premium. Flat roof garden room designs normally fit into this height range.
If you are looking for a pitched roof garden room, and want to comply with Permitted Development rules you will need to choose a garden room of a certain height.
For single pitched roofs, you will need to choose a model that is no more than 2.5m at the eaves and 3m high at the ridge; you will also need to situate the garden room more than 2m from the boundary.
For dual pitch roofs, you’ll need to choose a garden room with a maximum height of 2.5m at the eaves and 4m at the ridge, and site it more than 2m from the boundary to comply with Permitted Development.
There are other rules too!
Rule: No outbuilding on land forward of the wall forming the principle elevation – basically you can’t site a garden room in front of the front wall of your house i.e. in the front garden without Planning Permission.
Rule: No verandas, balconies or raised platforms – self explanatory, but you will need to apply for Planning Permission if you want a raised area around your garden room.
Rule: No more than half the area of land around the ‘original house’ to be covered in additions or other buildings – you can’t cover more than 50% of your garden with extensions to your house or other buildings without applying for Planning Permission.
You can get all the facts at the governments Planning Portal
Don’t be put off the idea of a garden room if you do need Planning Permission, most suppliers will handle this stage for you, submitting elevations, site plans and 3d visualisations of the proposed building in your garden. Most suppliers will include this service in their cost; all you will pay is the local authority application fee.
Building Regulations are a different issue to Planning Permission; Building Regulations are concerned with how well a building is built. Garden rooms under 15sqm, which most garden rooms are, don’t have to comply with Building Regulations, garden rooms between 15 and 30sqm don’t normally need Building Regulations as long as they are situated more than 1m from the boundary, however if you plan to use your garden room for sleeping accommodation e.g. a guest room, holiday let or granny annex then your building does need to comply with Building Regs, whatever size it is. This ruling is not designed as a hindrance, but is for your safety!
Because garden rooms are built like houses, many suppliers build their garden rooms to Building Regulation standards, as standard, but this is not always the case so please check