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Permitted development: Construction of new flats on commercial / mixed use or residential terraces and detached buildings

In addition to new permitted development rights to add residential storeys to existing blocks of flats (see here), to add storeys to your home (see here) and to demolish and rebuild certain buildings for residential purposes (see here), the Government has introduced a suite of further new permitted development rights to allow the construction of new flats on certain commercial and residential buildings. As with all new permitted development rights, there are many restrictions and conditions and care needed to ensure your proposed works fall within the scope of the right.

The new laws come into force on 31 August 2020 unless Parliament takes steps to prevent that from happening, which is very rare.

What is the new right?

Part 20 of Schedule 2 of the General Permitted Development Order 2020 introduces four new rights, Classes AA, AB, AC and AD, which take effect from 31 August 2020. The rights allow flats to be constructed on the topmost storey of certain buildings:

  • where buildings are used for any or a combination of Class A1, A2, A3 or B1(a) uses or use as betting offices, pay day loan shops or launderettes or a combination of one or more of such uses with a residential use (Eligible Use), Class AA applies to detached buildings of at least 3 storeys above ground and Class AB applies to terrace buildings
  • where buildings are used as single dwelling houses, Class AC applies to terrace buildings and Class AD to detached buildings

The rights allow up to two storeys to be added, but Classes AB, AC and AD allow only the addition of one further storey to single storey buildings.

In each case, the right covers certain other operations including works within the curtilage comprising:

  • engineering operations to strengthen walls and foundations (save visible support structures) and to install services
  • works to construct safe access and egress including fire escapes
  • works to construct storage, waste and ancillary facilities (but not on land forward of a principal elevation wall or forward of a side elevation wall fronting a highway)

Classes AA and AB also allow plant to be replaced or additional plant installed on the roof to serve the new flats provided there is existing plant and the new plant does not exceed the height of the existing plant.

Are there any limitations or restrictions?

The limitations, restrictions and conditions are extensive and the detail needs to be checked for the particular right in each case. The rights do not apply to:

  • listed buildings, scheduled monuments and land within their curtilages
  • conservation areas, areas of outstanding natural beauty, the Broads, national parks, World Heritage Sites and SSSIs and certain others areas
  • buildings which were not used for an Eligible Use or for a Class C3 residential use on 5 March 2018
  • buildings constructed before 1 July 1948 or after 5th March 2018

In addition:

  • the additional storeys must be built onto the principal part of the building
  • the internal floor to ceiling height of additional storeys cannot exceed the existing height of any storeys in the principal part of the existing building (but must not exceed 3m in height)
  • for Class AC and AD, the materials used in exterior works must be of similar appearance to the existing, the roof pitch must remain the same and the development must not include a window in any wall or roof slope in a side elevation
  • the height of the highest part of the roof as extended must not (excluding plant):
    • exceed the existing by more than 7m (Class AA) or 3.5m for existing one storey buildings and 7m for other buildings (Class AB, AC and AD)
    • exceed by more than 3.5m the highest part of the roofs across the terrace (Class AB and AC)
    • extend above 30m (Class AA) or 18m (Class AB, AC and AD)
  • Classes AB, AC and AD will not apply where the existing building has been enlarged by the addition of one or more storeys already

Consideration must be given to the standard provisions of the General Permitted Development Order, including where existing permissions disapply permitted development rights. Article 4 directions can also remove permitted development rights.

Are any approvals needed?

Yes, you must apply for the “prior approval” of the LPA in relation to factors which may include some or all of the following (depending on the Class):

  • the impact on the amenity of the existing building and adjoining premises including overlooking, privacy and the loss of light
  • external appearance, including the design and architectural features of the principal elevation and side elevations fronting a highway and the impact of some of the other works
  • air traffic and defence asset impacts and certain protected views
  • flood and contamination risks and transport and highway impacts
  • the provision of adequate natural light for habitable rooms in the new flats
  • the impact of noise from commercial premises on occupiers of the flats
  • the impact of the residential use on trade and business in the area

Before beginning, you must provide a report on construction management, covering the hours of operation and how adverse impacts of noise, dust, vibration and traffic will be mitigated.

The application for prior approval must comply with requirements including a description of the works and elevations and other assessments relating to the above factors. Neighbour notifications and consultation of certain third parties are required, giving the opportunity for representations to be made which must be taken into account.

The development cannot begin until prior approval is received (which may be conditional, depending on the nature of the development). There is no deemed approval provision. Prior approval can be refused if the LPA thinks that the proposal does not comply with the Regulations or insufficient information has been provided.

How long do I have to do the works?

Development must be completed within 3 years from the date prior approval is granted in accordance with the approved details.

Is there a fee?

Draft regulations have been published which, once in force, will introduce the following fees:

  • £334 per new dwelling for proposals of 50 or fewer new dwellings;
  • a fixed fee of £16,525 plus £100 per new dwelling for development proposals of more than 50 new dwellinghouses (subject to a maximum limit of £300,000).

The draft regulations also propose a "second application" exemption in certain circumstances.

For more information, please contact Claire Fallows.

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