Log cabin and summerhouse suppliers are very good at marketing and occasionally vague on planning rules. Most garden cabins are permitted development. A significant number are not — because they're too tall, too close to a boundary, or on a plot where conditions already restrict outbuildings.
Usually no — but the height, siting, and 50% coverage rule catch more people than the suppliers let on.
A log cabin or summerhouse is permitted development under Class E of the GPDO if it is single storey, maximum eaves height does not exceed 2.5 metres, overall height does not exceed 4 metres (dual-pitched roof) or 3 metres (any other roof type including flat and mono-pitch), is not within 2 metres of a boundary (which drops maximum height to 3 metres regardless of roof type), is behind the front wall of the house, does not take combined garden coverage over 50%, and is used for purposes incidental to the house.
This is the single most common log cabin planning mistake. Many contemporary log cabins use a mono-pitch or flat roof. These are limited to 3 metres maximum overall height — not 4 metres. Suppliers often advertise 3.5-metre mono-pitch cabins as permitted development. They are not.
Any outbuilding within 2 metres of any boundary is limited to 3 metres overall height regardless of roof type. The 50% garden coverage limit counts all outbuildings, extensions, and additions together — cabin plus existing garage plus existing shed plus extensions. On smaller plots this is frequently exceeded without the owner realising.
A log cabin used as a home office or hobby room is incidental to the house. One fitted with a kitchen, wet room, and rented on Airbnb is a separate dwelling requiring planning permission. Councils enforce on this. The planning record and the design of the structure are both examined.
Standard searches check the public register. We go further — querying live portals, blocked legacy systems, pre-merger authority databases, committee PDF archives, Land Registry title constraints, and comparable decisions across your postcode cluster. What we retrieve determines what you know before you build, buy, or appeal.