The Town and Country Planning (General Permitted Development) (England) Order 2015

Development not permitted

H.1  Development is not permitted by Class H if—

(a) the gross floor space of any new building erected would exceed—

(i) for a building on article 2(3) land or on a site of special scientific interest, 100 square metres;

(ii) in any other case, would exceed 200 square metres;

(b) the gross floor space of the original building would be exceeded by more than—

(i) in respect of an original building or a development on article 2(3) land, 10% or 500 square metres (whichever is lesser);

(ii) in respect of an original building or a development on a site of special scientific interest, 25% or 1,000 square metres (whichever is the lesser);

(iii) in any other case, 50% or 1,000 square metres (whichever is the lesser);

(c) the height of any part of the new building erected would exceed—

(i) if within 10 metres of a boundary of the curtilage of the premises, 5 metres;

(ii) in all other cases, the height of the highest building within the curtilage of the premises or 15 metres, whichever is lower;

(d) the height of the building as extended or altered would exceed—

(i) if within 10 metres of a boundary of the curtilage of the premises, 5 metres;

(ii) in all other cases, the height of the building being extended or altered;

(e) any part of the development would be within 5 metres of any boundary of the curtilage of the premises;

(f) the development would lead to a reduction in the space available for the parking or turning of vehicles; or

(g) the development would be within the curtilage of a listed building.