Class J: Solar equipment on non-domestic buildings

 

Class J covers solar equipment on non-domestic buildings. Microgeneration solar thermal equipment under J(a) and microgeneration solar PV under J(b) can be installed on a building, subject to roof and wall limits. Other solar PV under J(c) is limited to a roof.

The 56-day prior approval procedure in J.4(2) applies to J(c) only. The former 1 megawatt cap in J.3 was removed in December 2023.

 

Roof, wall and approval checks

Check projection on pitched and flat roofs, roof-edge setbacks, wall limits for J(a) and J(b), and the listed-building and scheduled-monument exclusions. J(c) requires a prior approval application before development begins; J(a) and J(b) do not have that Class J prior approval procedure. The 2023 amendment also removed the former protected-land highway-facing roof restriction in J.1(d).

Stand-alone panels within a non-domestic curtilage fall under Class K. Read current Part 14, Class J and the 2023 amending provision.

 

Legislation

 

Class J – installation or alteration etc of solar equipment on non-domestic premises

Permitted development

J. The installation, alteration or replacement of—

(a) microgeneration solar thermal equipment on a building;
(b) microgeneration solar PV equipment on a building; or
(c) other solar PV equipment on the roof of a building,
other than a dwellinghouse or a block of flats.

Development not permitted

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

(a) the solar PV equipment or solar thermal equipment would be installed on a pitched roof and would protrude more than 0.2 metres beyond the plane of the roof slope when measured from the perpendicular with the external surface of the roof slope;

(b) the solar PV equipment or solar thermal equipment would be installed on a flat roof, where the highest part of the solar PV equipment would be higher than 1 metre above the highest part of the roof (excluding any chimney);

(c) the solar PV equipment or solar thermal equipment would be installed on a roof and within 1 metre of the external edge of that roof;

(e) the solar PV equipment or solar thermal equipment would be installed on a site designated as a scheduled monument; or

(f) the solar PV equipment or solar thermal equipment would be installed on a listed building or on a building within the curtilage of a listed building.

J.2 Development is not permitted by Class J(a) or (b) if—

(a) the solar PV equipment or solar thermal equipment would be installed on a wall and would protrude more than 0.2 metres beyond the plane of the wall when measured from the perpendicular with the external surface of the wall;

(b) the solar PV equipment or solar thermal equipment would be installed on a wall and within 1 metre of a junction of that wall with another wall or with the roof of the building; or

(c) in the case of a building on article 2(3) land, the solar PV equipment or solar thermal equipment would be installed on a wall which fronts a highway.

Conditions

J.4— (1) Class J development is permitted subject to the following conditions—

(a) the solar PV equipment or solar thermal equipment must, so far as practicable, be sited so as to minimise its effect on the external appearance of the building and the amenity of the area; and
(b) the solar PV equipment or solar thermal equipment is removed as soon as reasonably practicable when no longer needed.

(2) Class J(c) development is permitted subject to the condition that before beginning the development the developer must apply to the local planning authority for a determination as to whether the prior approval of the authority will be required as to the design or external appearance of the development, in particular the impact of glare on occupiers of neighbouring land, and the following sub-paragraphs apply in relation to that application.

(3) The application must be accompanied by—

(a) a written description of the proposed development;
(b) a plan indicating the site and showing the proposed development;
(c) the developer’s contact address; and
(d) the developer’s email address if the developer is content to receive communications electronically;

together with any fee required to be paid.

(4) The local planning authority may refuse an application where, in the opinion of the authority—

(a) the proposed development does not comply with, or
(b) the developer has provided insufficient information to enable the authority to establish whether the proposed development complies with,

any conditions, limitations or restrictions specified in Class J applicable to the development in question.

(5) Sub-paragraphs (6) and (8) do not apply where a local planning authority refuses an application under sub-paragraph (4) and for the purposes of section 78 (appeals) of the Act such a refusal is to be treated as a refusal of an application for approval.

(6) The local planning authority must give notice of the proposed development—

(a) by site display in at least one place on or near the land to which the application relates for not less than 21 days of a notice which—
(i) describes the proposed development;
(ii) provides the address of the proposed development;
(iii) specifies the date by which representations are to be received by the local planning authority; or

(b) by serving a notice in that form on any adjoining owner or occupier.

(7) The local planning authority may require the developer to submit such information as the authority may reasonably require in order to determine the application.

(8) The local planning authority must, when determining an application—

(a) take into account any representations made to them as a result of any notice given under sub-paragraph (6); and
(b) have regard to the National Planning Policy Framework, so far as relevant to the subject matter of the prior approval, as if the application were a planning application.

(9) The development must not begin before the occurrence of one of the following—

(a) the receipt by the applicant from the local planning authority of a written notice of their determination that such prior approval is not required;
(b) the receipt by the applicant from the local planning authority of a written notice giving their prior approval; or
(c) the expiry of 56 days following the date on which the application under sub-paragraph (3) was received by the local planning authority without the authority notifying the applicant as to whether prior approval is given or refused.

(10) The development must be carried out—

(a) where prior approval is required, in accordance with the details approved by the local planning authority;
(b) where prior approval is not required, or where sub-paragraph (9)(c) applies, in accordance with the details provided in the application referred to in sub-paragraph (3),
unless the local planning authority and the developer agree otherwise in writing.

(11) The local planning authority may grant prior approval unconditionally or subject to conditions reasonably related to the subject matter of the prior approval.

(12) When computing the number of days in paragraph (6)(a), any day which is a public holiday must be disregarded.

 

 

 

 

Explore GPDO Part 14

 

 

Page updated: 24th September 2026