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Advice on outbuildings

The information on this webpage is a guide as to whether you will need to consider planning permission or building regulations when installing a shed/garden room/outbuilding/home office. 

If you wish to gain formal confirmation that the outbuilding you are planning does not require planning permission, you can submit an application for a Certificate of Lawfulness of Proposed Development.

This advice relates to houses. These rules do not apply to land/garden around a listed building, as planning permission would be required. Also for flats/maisonettes/mobile homes, planning permission is always necessary for this type of building.

Please be advised that new houses may not have the right to carry out works without planning permission (‘permitted development’ rights) as these can be withdrawn when planning permission is granted. If you live in a house which was constructed later than 1970 is it advisable to check whether your property has permitted development rights.
 

Planning Rules

Outbuildings are often considered to be ‘permitted development’. This means that formal planning permission is not required from the Council before construction starts. However, there are limits and conditions which need to be met. These are as follows:

  • Outbuildings must not cover more than 50% of the land/garden around your house.
  • Outbuildings must not be forward of the front wall of the house.
  • Outbuildings must be one storey and the eaves height must not exceed 2.5 metres. This should include any ground build up/base which may be needed to provide foundations.
Height of outbuilding
  • The total height of the building (including any ground build up/foundations/base) must not exceed the following:

        - 4 metres for a building with a dual-pitched roof
        - 2.5 metres if any part of the building is within 2 metres of any boundary
        - 3 metres in any other case (if you have a roof with a single slope, mono-pitched roof, a hipped roof or a flat roof)

  • The outbuilding cannot include a raised platform. This is defined as any decking/verandah/patio which is higher than 30cm above original ground level.
  • If your property is within a conservation area, you cannot place the outbuilding on land between a side wall of the house and the boundary.
  • The use of the outbuilding must be for a purpose which is “incidental” to the main house it would be associated with. Examples can include garden sheds, other storage buildings, garages, home office (to facilitate working from home rather than for use as a business premises which would generate deliveries/staff) and gym for your own or people living in the houses use. It does not, however, cover normal residential uses, such as separate self-contained accommodation or the use of an outbuilding for primary living accommodation such as a bedroom, bathroom or kitchen.

Further guidance on operating a business from home can be found here: https://www.stalbans.gov.uk/planning-faqs

You may also find the interactive house on the Planning Portal use:
https://www.planningportal.co.uk/info/200125/do_you_need_permission/90/interactive_house

Should you wish to gain formal confirmation that the outbuilding you are planning does not require planning permission you may wish to consider submitting an application for a Certificate of Lawfulness. Details of how to apply for this can be found here: https://www.stalbans.gov.uk/application-forms-and-validation-checklists

You can check on our website to find out if your house is a listed building or in a conservation area – please visit the District Mapping Service on our home page https://www.stalbans.gov.uk
 

Building Regulations

If you're interested in constructing a small, detached building like a garden shed or home office, it is important to consider the Building Regulations. Typically, regulations won't apply if:

  • The internal floor area is no larger than 15 square metres and there is no sleeping accommodation inside
  • The internal floor area is 15-30 square metres in size, building regulations will still be unnecessary as long as there are is no sleeping accommodation and the structure is situated at least one metre from any boundary. 

If the building is within a metre of the boundary, it has to made of substantially non-combustible materials.
Any waste, water and drainage connections need to comply with the Building Regulations and will require an application to Building Control.
LABC has further useful guidance.
 

Other matters

Please be aware that any runoff from the building should be onto your own land.

Remember, before you begin it is worth letting your neighbours know what you are planning.