New Permitted Developments to Extend Upwards, Demolish Buildings, and Create New Homes

New permitted developments rights are coming into force that will authorise the construction of additional storeys to existing buildings, or allow qualifying office premises or apartment blocks to be demolished to provide new homes. If a proposed scheme falls within the scope of these rights, then works will be able to be undertaken without express planning permission needing to be obtained, subject to discharging conditions and obtaining prior approvals.

An overview of the key aspects of these rights is provided below. However, as with all permitted development rights, these new provisions are subject to their own conditions and limitations as set out in the General Permitted Development Order 1 (“the GDPO”). We therefore recommend that further advice be sought upon any specific proposals before development is undertaken, and so that confirmation can be provided that any works would fall within the scope of the relevant right relied upon.

New Storeys on Detached Blocks of Flats

Part 20 of Schedule 2 of GDPO came into effect on 1 August 2020 2 , and Class A enables up to two
additional storeys to be added to the top of existing blocks of flats built before 5 March 2018 that do
not share a wall with any neighbouring buildings. The additional storeys must be built to provide
additional flats / apartments, and the extended building must not exceed 30 metres in height.


Prior Approvals relating to various matters must also be sought from the Local Planning Authority
before commencing any works, including in respect of highways, flooding, design, and amenity
impacts. The developer must also provide the planning authority with a report for the management
of the construction of the development prior to beginning the development.


Upward Extensions to Existing Houses, Commercial, and Mixed-Use Buildings to Provide New Homes

Various permitted development rights contained in Part 20 of Schedule 2 to the GDPO will come into
force on 31 August 2020 . These rights will enable the construction of additional storeys on buildings
in commercial, mixed, or residential use to provide new residential flats. Specifically:

  • Classes AA and AB authorise the upward extension of detached or terraced shops, restaurants / cafes, offices, or buildings in mixed use; and
  • Classes AC and AD grant consent for construction works to the topmost storey of a detached or terraced building in use as a single dwelling;

Subject to specific limitations, these rights will enable up to 2 storeys to provide new dwellings to be added to existing buildings (or 1 storey where existing buildings are of a single storey) The rights only apply to buildings constructed between 1 July 1948 and 5 March 2018. Various prior approvals will also need to be obtained from the relevant local planning authority before commencing works, including in respect of design and provision of natural light to new habitable rooms.

Additional Storeys to Existing Homes


New rights taking effect on 31 August 2020 contained in Class AA of Part 1 to the GDPO will also enable an existing dwelling to be enlarged by up to 2 storeys immediately above the topmost storey of the dwelling (or by 1 storey for single storey properties), even where the new storeys would not provide separate dwellings.

Various conditions and limitations apply to this right, including that the building must not have previously obtained permission for use as a dwelling through other permitted development classes. Prior Approvals in respect of (amongst other matters) design and amenity impacts must also be obtained before commencing works.

Demolition of Buildings and Construction of New Dwellings

From 31 August 2020, a new Class ZA 4 to Part 20 of Schedule 2 to the GDPO will come into force. This right will allow blocks of flats or other detached buildings with a B1 use (including offices) to be demolished in order to provide a new detached block of flats or a detached dwelling. Any new dwellings constructed pursuant to this permitted development right will automatically have conditions attached to it requiring that they remain in use as a dwellinghouse.


The building being demolished must have been constructed before 1990 and have a footprint of less than 1000 square metres in order for this right to apply. Prior approvals must also be obtained in respect of various matters before works are undertaken, with a further requirement for the building to have been vacant for at least 6 months prior to making any such application. The footprint of any new building must also fall within that of the previous building.

Our planning lawyers have extensive knowledge of permitted development legislation, and are able to advise upon any relevant conditions or limitations. We also regularly act in respect of prior approval applications, lawful development certificates, and any enforcement action being taken by planning authorities in respect of alleged unauthorised development. Please contact us if you have any questions as to the application of any permitted development rights to your scheme.

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