Certain types of development do not require planning consent because they are granted consent by law ( Town and Country Planning, General Permitted Development Order). Hence you have Permission to carry out certain limited forms of development without the need to make an application to a local planning authority.

Permitted development

H.      The installation, alteration or replacement of a microwave antenna on a dwellinghouse or within the curtilage of a dwellinghouse.

Development not permitted

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

 (a)    it would result in the presence on the dwellinghouse or within its curtilage of—

 (i)     more than two antennas;

(ii)    a single antenna exceeding 100 centimetres in length;

(iii)    two antennas which do not meet the relevant size criteria;

(iv)   an antenna installed on a chimney, where the length of the antenna would exceed 60 centimetres;

(v)    an antenna installed on a chimney, where the antenna would protrude above the chimney; or

(vi)   an antenna with a cubic capacity in excess of 35 litres;

(b)    in the case of an antenna to be installed on a roof without a chimney, the highest part of the antenna would be higher than the highest part of the roof;

(c)    in the case of an antenna to be installed on a roof with a chimney, the highest part of the antenna would be higher than the highest part of the chimney, or 60

        centimetres measured from the highest part of the ridge tiles of the roof, whichever is the lower; or

 (d)    in the case of article 1(5) land, it would consist of the installation of an antenna—

 (i)     on a chimney, wall or roof slope which faces onto, and is visible from, a highway;

        (ii)    in the Broads, on a chimney, wall or roof slope which faces onto, and is visible from, a waterway; or

        (iii)    on a building which exceeds 15 metres in height.

Conditions

 H.2   Development is permitted by Class H subject to the following conditions—

 (a)    an antenna installed on a building shall, so far as practicable, be sited so as to minimise its effect on the external appearance of the building; and

 (b)    an antenna no longer needed for reception or transmission purposes shall be removed as soon as reasonably practicable.

Interpretation of Class H

 H.3   The relevant size criteria for the purposes of paragraph H.1(a)(iii) are that:

 (a)    only one of the antennas may exceed 60 centimetres in length; and

 (b)    any antenna which exceeds 60 centimetres in length must not exceed 100 centimetres in length.

 H.4 The length of the antenna is to be measured in any linear direction, and shall exclude any projecting feed element, reinforcing rim, mounting or brackets.

Definitions:-

"HIGHWAY” - includes all public roads, footpaths, bridleways and byways.

ARTICLE 1(5) LAND – includes land within:

(a) a National Park;
(b) an Area of Outstanding Natural Beauty;
(c) an area designated by a local planning authority as a Conservation Area under Section 69 of the Planning (Listed Buildings and Conservation Areas) Act 1990;
(d) an area specified by the Secretary of State and the Minister of Agriculture, Fisheries and Food for the purposes of section 41(3) of the Wildlife and Countryside Act 1981 (enhancement and     protection of the natural beauty and amenity of the countryside)
(e)  the Norfolk and Suffolk Broads; and
(f) a World Heritage Site.