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


Development is not permitted by Class A(e) if—
(a) it would consist of or include the extension or alteration of a building so that—
(i) its design or external appearance would be materially affected;
(ii) the height of the original building would be exceeded, or the cubic content of the original building would be exceeded, by more than 25%; or
(iii) the floor space of the original building would be exceeded by more than 1,000 square metres;
or
(b) it would consist of the installation or erection of any plant or machinery exceeding 15 metres in height or the height of anything it replaces, whichever is the greater.

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Source: https://www.legislation.gov.uk/uksi/1995/418/schedule/2/part/16/crossheading/class-a/paragraph/A.1 (the official version)
Page: https://openlegislation.uk/town-and-country-planning-general-permitted-development-order-1995/schedule-2/part-16/crossheading-class-a/paragraph-A.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.