When my husband and I had the initial idea to start a bespoke summer house and garden office company, our first step was to research the regulations for outdoor structures to determine if planning permission would be required.

A child wearing a green hoodie and dark pants stands on a narrow path between two fences, surrounded by lush greenery. The child faces away, looking towards a house in the distance, possibly pondering how planning permission shaped this secluded and tranquil landscape. - a room in the garden

After searching online, I found many articles indicating that generally, garden buildings are permitted development and planning permission is usually not needed, provided certain criteria are met. This was reassuring, but the vague language like “in general” and “usually” still left some uncertainty.

To get definitive information, I knew I needed to consult the official documents directly. This was not a straightforward search, but I persevered and located the authoritative guidance! I was so pleased to have the official word in hand. Now I could be 100% confident the information was accurate.

As with many official documents, it was lengthy and complex in parts. But not to worry! I’ve summarized the key points for you here. And if you want to review the original guidance yourself, if you want to review the original guidance, you can find it here.

The criteria for garden buildings to be permitted development without needing planning permission are as follows:

1. The building should not be closer to a road or a public highway than the original house (The house as it was first built, or as it was as of 1 July 1948. An extension, even if done by the previous owner, is not considered original house, unless it was done before 1 July 1948.)

A 3D model of a plot with a white house, a green lawn, and three rectangular structures. Two of the structures are red and located to the sides of the house, while one is green and placed behind the house. The plot is bordered by a black road, highlighting its planning permission potential. - a room in the garden

2. The building should not occupy more than the 50% of the area surrounding the original house

A 3D model displaying two adjacent rectangular prisms, each marked with "50%". The left prism is red and larger, leading to a connected smaller green prism on the right. Both are attached to a white, house-shaped structure on the left side, indicating planning permission approval. - a room in the garden

3. In National Parks, Areas of Outstanding Natural Beauty or World Heritage Sites, if situated more than 20 metres away from any wall of the house, the building area can not exceed 10 metres square.

Illustration of two structures labeled "10sqm" in green and "10sqm+" in red at the end of a narrow path leading to a house on the other side. The path is 20 meters long, highlighting potential planning permission considerations. - a room in the garden

4. The building height should not exceed:
– 4 metres in the case of a building with a dual-pitched roof
– 2.5 metres in the case of a building within 2 metres of the boundary of the garden
– 3 metres in all other cases

A 3D diagram shows four white house models in a line with green detached structures at varying distances behind them, highlighting planning permission boundaries. Distances of 2m, 4m, 3m, 2m, and 2.5m are marked between the houses and structures on a gray and blue base. - a room in the garden

5. The building is not to be used as a self-contained accommodation

6. The building can not have an antenna

7. If the building is situated on top of decking, the latter can not exceed 30 cm in height

A 3D illustration showing a house with a connected yellow and green structure. The connection, colored in yellow and labeled "max 30cm", appears to be a pathway or bridge between the main house and green extension. Planning permission might be required for such modifications. - a room in the garden

I hope you have found this little article useful. But if you have any doubts or questions please do not hesitate to contact us. And for those of you that need a bit of inspiration have a look to our article 20 summer house idea to inspire you.

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