Garden Room Permitted Development in England
Updated: 1 December 2025
Reading Time: 3 minutes 10 seconds
When building a garden room, the first question you need to ask is, 'Do I need to apply for planning permission?' In many cases, the answer is no, but it’s essential to check your individual situation rather than rely on suppliers' claims that 'Planning Permission is Not Required.'
Whether you need to apply for planning permission depends on several factors, including where you live, how you plan to use the room, its size and roof shape, and how close it will be to the boundaries of your garden.
Fortunately, in many instances, you can build your garden room under Permitted Development rules. These rules govern the positioning and size of garden rooms and how much space they can occupy within your garden.
The Planning Portal’s Outbuilding Permitted Development page is the definitive guide to these rules. However, it can be difficult to interpret these regulations when considering the garden room you have in mind. To make things clearer, we’ve created this visual guide to garden room Permitted Development.
This article is part of a series that explores the rules you need to consider when building a garden room.
We’ll walk you through each rule as outlined on the Planning Portal:
Under Permitted Development, you cannot build a garden room in front of the main wall of your house. This means that if you want to place a garden room in your front garden, you will need to apply for planning permission.
Outbuildings and garages must be single-storey with a maximum eaves height of 2.5 metres and a maximum overall height of 4 metres for a dual-pitched roof or 3 metres for any other roof
Source: Planning Portal
1) The garden room must be single-storey.
2) A dual-pitched roof garden room can have eaves no higher than 2.5 metres and a ridge height no taller than 4 metres. Garden rooms with this roof style must be positioned more than 2 metres from any boundary.
3) For a mono-pitch (single-sloped) roof, the eaves can be no higher than 2.5 metres and the ridge no taller than 3 metres. These structures also need to be sited more than 2 metres from your garden boundaries.
Maximum height of 2.5 metres if the building is within 2 metres of a boundary
Source: Planning Portal
If you plan to place your garden room within 2 metres of any boundary, such as a fence, wall, or hedge, it must not exceed a height of 2.5 metres. This generally requires a flat-roof design.
No verandas, balconies, or raised platforms (platforms must not exceed 0.3 metres in height)
Source: Planning Portal
It’s popular to add a deck or veranda outside a garden room. According to this rule, any deck or veranda must not be higher than 300mm.
No more than half of the land around the "original house" can be covered by additions or other buildings
Source: Planning Portal
The term "original house" refers to the house as it was originally built, or as it stood on 1 July 1948 (if built before that date). Even if you haven’t extended the house, a previous owner may have.
This rule states that any existing extensions, such as conservatories, sheds, greenhouses, or decking, combined with the new garden room, must not cover more than 50% of the land surrounding your home.
If you live in a National Park, the Broads, an Area of Outstanding Natural Beauty, or a World Heritage Site
Source: Planning Portal
If you live in a protected landscape like a National Park, the Broads, an Area of Outstanding Natural Beauty, or a World Heritage Site, additional rules apply to garden rooms built under Permitted Development. Planning consultants R L Planning have created a helpful guide that outlines these extra requirements.
If you live in a Listed Building
If your home is a Listed Building, you will need to apply for planning permission to build a garden room.
If you live in a Flat or Maisonette
Flats and maisonettes do not have Permitted Development rights. If you live in one and wish to build a garden room, you must apply for planning approval. The Planning Portal provides detailed guidance on the rules for common projects in these cases.
Apply for a Lawful Development Certificate
It’s a good idea to apply for a Lawful Development Certificate when building a garden room under Permitted Development. This certificate verifies that the work complies with current regulations.
Although there is a cost involved in obtaining this certificate, it can be extremely beneficial when selling your house, as solicitors may request it during the conveyancing process. Some garden room companies will handle the certificate application for you, but it is also straightforward to apply for it yourself.
