Permitted development: a right to add new storeys to your home
What is the new right?
From 31 August 2020, a new permitted development right will allow you to construct up to two additional storeys to dwelling houses consisting of at least two storeys, and one additional storey to one storey dwelling houses. The new storeys must be immediately above the topmost storey. The right also covers any engineering operations reasonably necessary for construction comprising works within the curtilage to strengthen existing walls or foundations. There are provisions as to what constitutes a storey in terms of basements and roof accommodation.
Perhaps surprisingly, the rights do apply to listed buildings. However, listed building consent will be required for any works that affect the building’s character as a building of special architectural or historic interest.
Are there any limitations or restrictions?
The rights do not apply to:
- buildings converted to residential under permitted development rights
- conservation areas, areas of outstanding natural beauty, the Broads, national parks, world heritage sites and SSSIs
- buildings constructed before 1 July 1948 or after 28 October 2018
- where the existing dwelling house has been enlarged already by the addition of one or storeys whether under permitted development or otherwise
There are other restrictions:
- following the works, the height of the highest part of the roof
- cannot exceed 18m or the highest part of the roof as existing by more than 3.5m for one storey dwellings or 7m otherwise
- cannot exceed by more than 3.5m the highest part of the roof of:
- for semi-detached houses, the building with which it shares a party wall
- for terraces, every other building in the same row
- the internal floor to ceiling height of additional storeys cannot exceed the lower of 3m and the existing height of any storeys in the principal part of the existing house
- the new storeys must only be constructed on the principal part of the house ie the main part, excluding extensions of lower height whether original or subsequent
- no visible support structures on or attached to the exterior on completion are allowed
- no windows are allowed in walls or roof slopes on side elevations and the roof pitch of the principal part must be the same
- the materials used in exterior works must be of similar appearance to the existing
Consideration also needs to be given to the standard provisions of the General Permitted Development Order, including where existing permissions disapply permitted development rights.
Are any approvals needed?
Yes, you must apply for the “prior approval” of the LPA in relation to the following factors:
- the impact on the amenity of 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
- air traffic and defence asset impacts and certain protected views
Before beginning, you must also 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). 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.
Is there a fee?
As it stands, fees are not payable for prior approval applications of this category. However, it remains to be seen whether a fee will be introduced.
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.