A single storey rear extension can fall under permitted development, meaning planning permission may not be required providing it meets certain criteria.  

In terms of height, the extension must:

• Be no taller than four metres at its highest point

• Have eaves no higher than the eaves of the original house

• Not exceed the height of the original dwelling  

Read about planning permission for extensions on Planning Portal

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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.

Find a competent person

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.

Read about the limits and conditions for outbuildings

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Planning permission may be required for external insulation if it impacts the external appearance of the building. If materials are of a similar appearance to those used in the construction of the house, then permission will likely not be required.

Listed buildings will require listed building consent for any significant work.

If you live in a Conservation Area or other protected area you will need to apply for planning permission before making changes to the outside of your house.

Further information and building regulations advice is available on Planning Portal. Read our external walls common project.

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A 'listed building' is a building, object or structure in the UK that has been considered as of national importance in terms of architectural or historic interest and included on a register called the List of Buildings of Special Architectural or Historic Interest.

Buildings are listed to help protect the physical evidence of our past, including buildings, which are valued and protected as a central part of our cultural heritage and our sense of identity. Historic buildings also add to the quality of our lives, being an important aspect of the character and appearance of our towns, villages, and countryside.

There are three listing grades:

- Grade I - Buildings of exceptional interest

- Grade II* - Particularly important and more than special interest

- Grade III - Buildings of special interest, warranting every effort being made to preserve them (this is the most common)

If you live in a listed building it means you cannot demolish or alter the building in a way that changes its character without Listed Building Consent.

Read detailed guidance on Listed Building Consent