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Do summerhouses or garden offices need building regulations approval?
If you plan to put up a small, detached building like a garden shed, garden room, garden office, annexe or summerhouse (all classed as outbuildings), building regulations generally won’t apply if the building has a floor area under 15 square metres and does not include any sleeping accommodation.
For buildings with a floor area between 15 and 30 square metres, building regulations approval is usually not needed - as long as the building does not include sleeping accommodation and either:
- it is at least one metre away from any boundary, or
- it is built mainly from non-combustible materials.
Read more about the building regulations that apply to outbuildings.
Don't forget to check the permitted development rights for outbuildings.
Common Questions
In many cases, yes. Converting a single residential property (Class C3) into a small House in Multiple Occupation (HMO) for up to six occupants can often be done under permitted development rights, specifically under Class L. This means that planning permission isn’t usually required.
However, if your property is located in an area covered by an Article 4 Direction, permitted development rights are removed, and you would need to apply for full planning permission to change the use from C3 (dwellinghouse) to C4 (HMO).
Read more information about use class changes on Planning Portal
Planning permission will not be require to add an en-suite provided it is within the existing building and not part of a wider project such as an extension.
Building regulations will have to be considered when adding an en-suite as it impacts drainage, ventilation and electrics. It is recommended that you have the work completed by a member of the competent person scheme.
Rules governing outbuildings apply to sheds, playhouses, greenhouses and garages as well as other ancillary garden buildings such as swimming pools, ponds, sauna cabins, kennels, enclosures (including tennis courts) and many other kinds of structures for a purpose incidental to the enjoyment of the dwellinghouse.
If you are unsure if your planned building falls into the category of 'outbuildings' or if you are unsure if planning permission is required, please contact your local planning authority.
Outbuildings are considered to be permitted development, not needing planning permission, subject certain limits and conditions.
Whether you need planning permission to install an extractor fan depends on the size and placement of the fan.
For domestic installations, such as a bathroom or kitchen in your house, planning permission is not generally required. If the change significantly alters the external appearance of your home then permission may be required.
If you live in a listed building, you will need listed building consent for any significant changes.
Larger extractor fans for businesses are likely to require an application for planning permission to be made to the local planning authority. These extractors can impact the local area due to their noise, visibility and odour, as such the planning authority will need to assess the change.
Building regulations relating to ventilation and electrical works will have to be complied with, these are covered by Approved Document F and P respectively.
Read more about building regulations and the requirement for ventilation on our common projects.
If you plan to put up a small, detached building like a garden shed, garden room, garden office, annexe or summerhouse (all classed as outbuildings), building regulations generally won’t apply if the building has a floor area under 15 square metres and does not include any sleeping accommodation.
For buildings with a floor area between 15 and 30 square metres, building regulations approval is usually not needed - as long as the building does not include sleeping accommodation and either:
- it is at least one metre away from any boundary, or
- it is built mainly from non-combustible materials.
Read more about the building regulations that apply to outbuildings.
Don't forget to check the permitted development rights for outbuildings.
