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The relaxation of Permitted Development Rights


Since the end of August 2020, greater freedom has been given to those in England who would like to extend and expand their homes upwards under Permitted Development rights. This means that certain types of domestic construction can be undertaken without having to first obtain full planning permission. Previous rights allowed for smaller projects to be undertaken, but the changes now include larger projects, alongside more commercial freedom including converting office buildings into residential flats and adding new dwellings above certain existing detached buildings to help meet the high demand for new housing.


For domestic buildings, the new Permitted Development rights allow you to construct up to an additional two storeys above an existing two storey (or more) house, and one additional storey above an existing one storey (or more) house. This surprisingly includes some listed buildings - although anything affecting the character of a building of special architectural or historic interest will still need listed building consent. Properties built before 1948 are also not included within these changes, but the previous Permitted Development rights may still apply. It is important to keep in mind that any work undertaken on a house after 1948 counts towards that property’s allocation of rights, so a check on the history of a property will show what already might have been carried out.


Before undertaking any work, it is advisable to check with a local planning authority or qualified surveyor or architect that your plans do not require a full planning submission.


What is allowed under the current Permitted Development rights:


Rear and side extensions:

  • Can extend up to 3m from the rear wall of the original house if the house is attached to another, or 4m if detached. Some property types, subject to prior approval, are allowed single storey extensions up to 8m if a detached house, or 6m for attached properties

  • The property once extended cannot fill more than 50% of the land around the original house

  • Any extension must not be within 7m of any boundary opposite the rear of a house if the extension is above one storey

  • Is not more than 50% of the width of the original house for side extensions

  • Can be up to 4m in height, or 3m if within 2m of a property boundary and not more than one storey tall

  • Materials are to be similar to the existing house

  • Extension is not taller than the existing house, including eaves and roof, and

  • Covers less than 50% of the size of land around the original house (as at 1st July 1948 or the date it was built if after 1948)

  • Wraparound extensions (to the side and rear) are unlikely to fall under permitted development and advice should be sought from a qualified architect or the local planning authority

Loft conversions:

  • Up to 50 cubic metres of additional roof space can be created for detached and semi-detached homes

  • Materials are to be similar to the existing house

  • The roof pitch of the extension must be the same as of the existing house

  • Dormer walls must be set back at least 20cm from the existing wall

  • Must have non opening windows if they are less than 1.7m from floor level, and any windows in the side must be obscure-glazed

Additional storeys:

  • Two storeys can be added to homes taller than two storeys, for one storey properties one storey can be added subject to the other restrictions listed below

  • Other criteria are as for rear and side extensions

  • No windows in side elevations, including roof slope, in additional storeys to protect neighbours’ privacy and the roof pitch must remain as existing

  • Materials are to be similar to the existing house

What is not included:

  • Buildings already converted to residential under Permitted Development rights

  • Conservation areas, areas of outstanding national beauty, national parks, world heritage sites and SSSIs

  • Buildings built before 1948 or after 2018, so pre-war houses and modern developments are excluded

  • Buildings that have already been increased by the addition of one storey or more whether under Permitted Development or otherwise

  • Flats and maisonettes

Other restrictions:

  • The completed building can not be taller than 18m, or the highest part of the roof cannot be 3.5m taller than the next tallest neighbour

  • Semi-detached houses cannot exceed the highest part of buildings it shares a party wall with by more than 3.5m, or be more than 3.5m taller any other building in the same row for terraced houses

  • Internal floor to ceiling heights of additional storeys cannot exceed 3m (or the existing height of any existing storeys in the house, whichever is lower)

  • Additional storeys can only be constructed over the principal part of the house, not extensions of a lower height

  • No visible support structures on or attached to the exterior upon completion

Approvals that might still be needed:


Whilst a full planning application may not be required for a project, there are still a number of requirements that will need to be met:

  • Party Wall matters

  • UK Building Regulations

  • Right to Light

Prior approval is required before work can begin to protect:

  • The impact on the amenity of adjoining properties including overlooking, privacy and loss of light

  • External appearance, including the principal elevations and any side elevations fronting a street

  • Air traffic and defence asset impacts and certain protected views

  • A construction management report must be provided before beginning, showing hours of operations and how the impact of noise, dust and traffic will be mitigated

Neighbour consultations and notifications will be required so any objections to the proposed plans can be lodged before approval is given, and once granted, the work must be completed within 3 years of the date prior approval is granted.

The latest changes to the Permitted Development legislation have not been met with universal applause. Critics are concerned that this will herald poor quality design being allowed without the scrutiny against planning policies of local areas, and especially in the commercial sector, that sub-standard accommodation could be generated in order to maximise profit. It remains to be seen how far future changes to planning legislation will go, but the latest changes announced this summer should come as good news to those private homeowners looking to add more space to their properties for personal use.

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