# The Town and Country Planning General Development Order 1988, Paragraph A.1: Development not permitted


Development is not permitted by Class A if—
(a) in the case of any plant or machinery installed, extended, altered or replaced pursuant to this permission, that plant or machinery—
(i) would, if the land or pier is within 3 kilometres of the perimeter of an aerodrome, exceed a height of 25 metres or the height of the highest existing structure (whichever is the lesser), or
(ii) would in any other case exceed a height of 25 metres;
(b) in the case of an extension to an existing building or structure, that building or structure would as a result exceed 5 metres above ground level or the height of the roof of the existing building or structure, whichever is the greater; or
(c) in any other case, the height of the building or structure erected, extended, altered or replaced would exceed 5 metres above ground level.

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Source: https://www.legislation.gov.uk/uksi/1988/1813/schedule/2/part/28/chapter/1/paragraph/A.1 (the official version)
Page: https://openlegislation.uk/town-and-country-planning-general-development-order-1988/schedule-2/part-28/chapter-1/paragraph-A.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.