# The Town and Country Planning (General Permitted Development) Order 1995, Paragraph B.1: Development not permitted


Development is not permitted by Class B if—
(a) the building as extended or altered is to be used for purposes other than those of—
(i) the Crown; or
(ii) the provision of employee facilities;
(b) the height of the building as extended or altered would exceed the height of the original building;
(c) the cubic content of the original building would be exceeded by more than—
(i) 10%, in respect of development on any article 1(5) land; or
(ii) 25%, in any other case;
(d) the floor space of the original building would be exceeded by more than—
(i) 500 square metres in respect of development on any article 1(5) land; or
(ii) 1,000 square metres in any other case;
(e) the external appearance of the original building would be materially affected;
(f) any part of the building as extended or altered would be within 5 metres of any boundary of the curtilage of the original building; or
(g) the development would lead to a reduction in the space available for the parking or turning of vehicles.

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Source: https://www.legislation.gov.uk/uksi/1995/418/schedule/2/part/34/chapter/2/paragraph/B.1 (the official version)
Page: https://openlegislation.uk/town-and-country-planning-general-permitted-development-order-1995/schedule-2/part-34/chapter-2/paragraph-B.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.