The first question you need to ask yourself when building a garden room is 'do I need to apply for Planning Permission?'. In many cases, the answer is no, but you must check your individual position and not rely on suppliers websites which say 'Planning Permission Not Required'.
Whether you will need to make a planning application very much depends on where you live, what you are planning to use the room for, it's size and roof shape and how close to the boundaries of your garden you want to site it.
Luckily, in a lot of cases you can build your garden room under the Permitted Development rules. These rules dictate the positioning of different shapes of garden room and how much space they can take up in your garden.
These rules are clearly laid out on the Planning Portal's Outbuilding Permitted Development page, and that page is the definitive guide on the subject. The thing is it can be difficult to relate this list of rules to the garden room you have your eye on. We have therefore created this page as a visual guide to garden room Permitted Development.
We'll walk you through each rule as they are stated on the Planning Portal:
No outbuilding on land forward of a wall forming the principal elevation
You can’t build a garden room beyond the front wall of your house under Permitted Development. This means if you want to put a garden room in the front garden of your house you will need to apply for Planning Permission to do so.
Outbuildings and garages to be single storey with maximum eaves height of 2.5 metres and maximum overall height of 4 metres with a dual pitched roof or 3 metres for any other roof
This rule is telling us several things:
1) The garden room must be single storey. If you want to build a two storey garden room, you will need to apply for Planning Permission.
2) This rule is also telling us that a dual pitched roof garden room should be no higher than 2.5 metres at the eaves and no taller than 4 metres at the ridge. Garden rooms with this shape roof need to be sited more than 2 metres from each boundary.
3) Single sloped roof garden rooms, also known as mono pitch roofs, can be no taller than 2.5 metres at the eaves and 3 metres at the ridge to comply with Permitted Development rules. They should also be sited more than 2 metres from each of your garden’s boundaries.
Maximum height of 2.5 metres in the case of a building, enclosure or container within 2 metres of a boundary of the curtilage of the dwelling house
If you want to place your garden room within 2 metres of any boundary, i.e. your fence wall or hedge, it can be no taller than 2.5 metres high. In most cases, this dictates a flat roof garden room.
No verandas, balconies or raised platforms
This rule is saying that you can’t add a veranda, deck or balcony to your garden room under Permitted Development. However, the page for Permitted Development rules for decks says they can be built under Permitted Development as long as they are no higher than 300mm (1ft) and when combined with other structures don’t cover more than 50% of your garden.
Here is the wording:
Putting up decking, or other raised platforms, in your garden is permitted development, not needing an application for planning permission, providing: The decking is no more than 30cm above the ground together with other extensions, outbuildings, etc., the decking or platforms cover no more than 50 percent of the garden area.
No more than half the area of land around the “original house” would be covered by additions or other buildings. The term “original house” means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so
You may already have additions to your house like conservatories and sheds, greenhouses and decking. These buildings combined with the garden room should not cover more than 50% of your garden.
If you live in a Listed Building, within a National Park, in an Area of Outstanding Beauty, The Broads or a World Heritage site you WILL NEED TO APPLY FOR PLANNING PERMISSION TO BUILD A GARDEN ROOM.
We have always found the Planning Department to be helpful, and it’s worth having a chat with your local planning office before you decide on a garden room to check your individual position in regards to Planning Permission.
You could make a Pre-planning application or apply for a Certificate of Lawfulness to ensure your building applies with the Permitted Development rules. There is a cost involved in this, but it’s worth it for the peace of mind.