Town And Country Planning, England Citation and commencement 1 This Order may be cited as the Town and Country Planning (General Permitted Development) (England) (Amendment) (No. 2) Order 2020 and comes into force at 9.00 a.m. on 31st August 2020. Amendments to the Town and Country Planning (General Permitted Development) (England) Order 2015 2 The Town and Country Planning (General Permitted Development) (England) Order 2015 is amended in accordance with articles 3 and 4. Amendments to Part 1 of Schedule 2 3 1 Part 1 of Schedule 2 (permitted development rights - development within the curtilage of a dwellinghouse) is amended as follows. 2 After Class A (enlargement, improvement or other alteration of a dwellinghouse) insert— Class AA - enlargement of a dwellinghouse by construction of additional storeys Permitted development AA The enlargement of a dwellinghouse consisting of the construction of— a up to two additional storeys, where the existing dwellinghouse consists of two or more storeys; or b one additional storey, where the existing dwellinghouse consists of one storey, immediately above the topmost storey of the dwellinghouse, together with any engineering operations reasonably necessary for the purpose of that construction. Development not permitted AA.1 Development is not permitted by Class AA if— a permission to use the dwellinghouse as a dwellinghouse has been granted only by virtue of Class M, N, O, P, PA or Q of Part 3 of this Schedule (changes of use); b the dwellinghouse is located on— i article 2(3) land; or ii a site of special scientific interest; c the dwellinghouse was constructed before 1st July 1948 or after 28th October 2018; d the existing dwellinghouse has been enlarged by the addition of one or more storeys above the original dwellinghouse, whether in reliance on the permission granted by Class AA or otherwise; e following the development the height of the highest part of the roof of the dwellinghouse would exceed 18 metres; f following the development the height of the highest part of the roof of the dwellinghouse would exceed the height of the highest part of the roof of the existing dwellinghouse by more than— i 3.5 metres, where the existing dwellinghouse consists of one storey; or ii 7 metres, where the existing dwellinghouse consists of more than one storey; g the dwellinghouse is not detached and following the development the height of the highest part of its roof would exceed by more than 3.5 metres— i in the case of a semi-detached house, the height of the highest part of the roof of the building with which it shares a party wall (or, as the case may be, which has a main wall adjoining its main wall); or ii in the case of a terrace house, the height of the highest part of the roof of every other building in the row in which it is situated; h the floor to ceiling height of any additional storey, measured internally, would exceed the lower of— i 3 metres; or ii the floor to ceiling height, measured internally, of any storey of the principal part of the existing dwellinghouse; i any additional storey is constructed other than on the principal part of the dwellinghouse; j the development would include the provision of visible support structures on or attached to the exterior of the dwellinghouse upon completion of the development; or k the development would include any engineering operations other than works within the curtilage of the dwellinghouse to strengthen its existing walls or existing foundations. Conditions AA.2 1 Development is permitted by Class AA subject to the conditions set out in sub-paragraphs (2) and (3). 2 The conditions in this sub-paragraph are as follows— a the materials used in any exterior work must be of a similar appearance to those used in the construction of the exterior of the existing dwellinghouse; b the development must not include a window in any wall or roof slope forming a side elevation of the dwelling house; c the roof pitch of the principal part of the dwellinghouse following the development must be the same as the roof pitch of the existing dwellinghouse; and d following the development, the dwellinghouse must be used as a dwellinghouse within the meaning of Class C3 of the Schedule to the Use Classes Order and for no other purpose, except to the extent that the other purpose is ancillary to the primary use as a dwellinghouse. 3 The conditions in this sub-paragraph are as follows— a before beginning the development, the developer must apply to the local planning authority for prior approval as to— i impact on the amenity of any adjoining premises including overlooking, privacy and the loss of light; ii the external appearance of the dwellinghouse, including the design and architectural features of— aa the principal elevation of the dwellinghouse, and bb any side elevation of the dwellinghouse that fronts a highway; iii air traffic and defence asset impacts of the development; and iv whether, as a result of the siting of the dwellinghouse, the development will impact on a protected view identified in the Directions Relating to Protected Vistas dated 15th March 2012 issued by the Secretary of State; b before beginning the development, the developer must provide the local planning authority with a report for the management of the construction of the development, which sets out the proposed development hours of operation and how any adverse impact of noise, dust, vibration and traffic on adjoining owners or occupiers will be mitigated; c the development must be completed within a period of 3 years starting with the date prior approval is granted; d the developer must notify the local planning authority of the completion of the development as soon as reasonably practicable after completion; and e that notification must be in writing and include— i the name of the developer; ii the address of the dwellinghouse; and iii the date of completion. Procedure for applications for prior approval AA.3 1 The following sub-paragraphs apply where an application to the local planning authority for prior approval is required by paragraph AA.2(3)(a) 2 The application must be accompanied by— a a written description of the proposed development, including details of any works proposed; b a plan which is drawn to an identified scale and shows the direction of North, indicating the site and showing the proposed development; and c a plan which is drawn to an identified scale and shows— i the existing and proposed elevations of the dwellinghouse, and ii the position and dimensions of the proposed windows. 3 The local planning authority may refuse an application where, in its opinion— 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 paragraphs AA.1 and AA.2. 4 Sub-paragraphs (5) to (8) do not apply where a local planning authority refuses an application under sub-paragraph (3); 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. 5 The local planning authority must notify each adjoining owner or occupier about the proposed development by serving on them a notice which— a describes the proposed development, including the maximum height of the proposed additional storeys; b provides the address of the proposed development; and c specifies the date, which must not be less than 21 days from the date the notice is given, by which representations are to be received by the local planning authority. 6 Where the application relates to prior approval as to the impact on air traffic or defence assets, the local planning authority must consult any relevant operators of aerodromes, technical sites or defence assets and where appropriate the Civil Aviation Authority and the Secretary of State for Defence. 7 Where an aerodrome, technical site or defence asset is identified on a safeguarding map provided to the local planning authority, the local planning authority must not grant prior approval contrary to the advice of the operator of the aerodrome, technical site or defence asset, the Civil Aviation Authority or the Secretary of State for Defence. 8 Where the application relates to prior approval as to the impact on protected views, the local planning authority must consult Historic England, the Mayor of London and any local planning authorities identified in the Directions Relating to Protected Vistas dated 15th March 2012 issued by the Secretary of State. 9 The local planning authority must notify the consultees referred to in sub-paragraphs (6) and (8) specifying the date by which they must respond, being not less than 21 days from the date the notice is given. 10 When computing the number of days in sub-paragraphs (5)(c) and (9), any day which is a public holiday must be disregarded. 11 The local planning authority may require the developer to submit such information as the authority may reasonably require in order to determine the application, which may include— a assessments of impacts or risks; b statements setting out how impacts or risks are to be mitigated, having regard to the National Planning Policy Framework issued by the Ministry of Housing, Communities and Local Government in February 2019 ; and c details of proposed building or other operations. 12 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 (5) and any consultation under sub-paragraph (6) or (8); and b have regard to the National Planning Policy Framework issued by the Ministry of Housing, Communities and Local Government in February 2019, so far as relevant to the subject matter of the prior approval, as if the application were a planning application. 13 The development must not begin before the receipt by the applicant from the local planning authority of a written notice giving their prior approval. 14 The development must be carried out in accordance with the details approved by the local planning authority. 15 The local planning authority may grant prior approval unconditionally or subject to conditions reasonably related to the subject matter of the prior approval. Interpretation of Class AA AA4 1 For the purposes of Class AA— “defence asset” means a site identified on a safeguarding map provided to the local planning authority for the purposes of a direction made by the Secretary of State in exercise of the powers conferred by article 31(1) of the Procedure Order or any previous powers to the like effect ; “detached”, in relation to a dwellinghouse, means that the dwellinghouse does not— share a party wall with another building; or have a main wall adjoining the main wall of another building; “principal part”, in relation to a dwellinghouse, means the main part of the dwellinghouse excluding any front, side or rear extension of a lower height, whether this forms part of the original dwellinghouse or is a subsequent addition; “semi-detached”, in relation to a dwellinghouse, means that the dwellinghouse is neither detached nor a terrace house; “technical sites” has the same meaning as in the Town and Country Planning (Safeguarded Aerodromes, Technical Sites and Military Explosives Storage Areas) Direction 2002 ; “terrace house” means a dwellinghouse situated in a row of three or more buildings, where— it shares a party wall with, or has a main wall adjoining the main wall of, the building on either side; or if it is at the end of a row, it shares a party wall with, or has a main wall adjoining the main wall of, a building which fulfils the requirements of paragraph a. 2 In Class AA references to a “storey” do not include— a any storey below ground level; or b any accommodation within the roof of a dwellinghouse, whether comprising part of the original dwellinghouse or created by a subsequent addition or alteration, and accordingly, references to an “additional storey” include a storey constructed in reliance on the permission granted by Class AA which replaces accommodation within the roof of the existing dwellinghouse. . 3 In Class B (additions etc to the roof of a dwellinghouse), in paragraph B.1 (development not permitted) — a at the end of sub-paragraph (f) omit “or”; b at the end of sub-paragraph (g) insert— ; or h the existing dwellinghouse has been enlarged in reliance on the permission granted by Class AA (enlargement of a dwellinghouse by construction of additional storeys). . 4 In paragraph I (interpretation of Part 1), in the definition of “terrace house”, before “means” insert “, except in Class AA (enlargement of a dwellinghouse by construction of additional storeys),”. Amendments to Part 20 of Schedule 2 4 1 Part 20 of Schedule 2 (permitted development rights - construction of new dwellinghouses) is amended as follows. 2 In Class A (new dwellinghouses on detached blocks of flats)— a in sub-paragraph (c) of paragraph A (permitted development), for “access and egress to” substitute “access to and egress from”; b in paragraph A.1 (development not permitted)— i for sub-paragraph (e) substitute— e the floor to ceiling height of any additional storey, measured internally, would exceed the lower of— i 3 metres; or ii the floor to ceiling height, measured internally, of any storey of the principal part of the existing building; ; ii for sub-paragraph (g) substitute— g the height of the highest part of the roof of the extended building would exceed the height of the highest part of the roof of the existing building by more than 7 metres (not including plant, in each case); ; iii for sub-paragraph (h) substitute— h the height of the highest part of the roof of the extended building (not including plant) would be greater than 30 metres; ; iv in sub-paragraph (l), for “new building” substitute “extended building”. 3 After Class A insert— Class AA - new dwellinghouses on detached buildings in commercial or mixed use Permitted development AA 1 Development consisting of works for the construction of up to two additional storeys of new dwellinghouses immediately above the topmost storey on a detached building to which sub-paragraph (2) applies, together with any or all— a engineering operations reasonably necessary to construct the additional storeys and new dwellinghouses; b works for the replacement of existing plant or installation of additional plant on the roof of the extended building reasonably necessary to service the new dwellinghouses; c works for the construction of appropriate and safe access to and egress from the new dwellinghouses and existing premises in the building, including means of escape from fire, via additional external doors or external staircases; d works for the construction of storage, waste or other ancillary facilities reasonably necessary to support the new dwellinghouses. 2 This sub-paragraph applies to a building which is— a used for any purpose within Class A1 (shops), Class A2 (financial and professional services), Class A3 (restaurants and cafes) or Class B1(a) (offices) of the Schedule to the Use Classes Order, or as a betting office, pay day loan shop or launderette; b in a mixed use combining— i two or more uses within paragraph (a); or ii a use falling within Class C3 (dwellinghouses) of the Schedule to the Use Classes Order, together with one or more uses within paragraph (a). Development not permitted AA.1 Development is not permitted by Class AA if— a above ground level, the building is less than three storeys in height; b the building was constructed before 1st July 1948 or after 5th March 2018; c on 5th March 2018 the building was in a use other than— i a use or mixed use within paragraph AA(2)(a) or (b); or ii a use falling within Class C3 of the Schedule to the Use Classes Order; d the additional storeys are constructed other than on the principal part of the building; e the floor to ceiling height of any additional storey, measured internally, would exceed the lower of— i 3 metres; or ii the floor to ceiling height, measured internally, of any storey of the principal part of the existing building; f the new dwellinghouses are not flats; g the height of the highest part of the roof of the extended building would exceed the height of the highest part of the roof of the existing building by more than 7 metres (not including plant, in each case); h the height of the highest part of the roof of the extended building (not including plant) would be greater than 30 metres; i development under Class AA(1)(a) would include the provision of visible support structures on or attached to the exterior of the building upon completion of the development; j development under Class AA(1)(a) would consist of engineering operations other than works within the existing curtilage of the building to— i strengthen existing walls; ii strengthen existing foundations; or iii install or replace water, drainage, electricity, gas or other services; k in the case of Class AA(1)(b) development there is no existing plant on the building; l in the case of Class AA(1)(b) development the height of any replaced or additional plant as measured from the lowest surface of the new roof on the principal part of the extended building would exceed the height of any existing plant as measured from the lowest surface of the existing roof on the principal part of the existing building; m development under Class AA(1)(c) would extend beyond the curtilage of the existing building; n development under Class AA(1)(d) would— i extend beyond the curtilage of the existing building; ii be situated on land forward of a wall forming the principal elevation of the existing building; or iii be situated on land forward of a wall fronting a highway and forming a side elevation of the existing building; or o the land or site on which the building is located, is or forms part of— i article 2(3) land; ii a site of special scientific interest; iii a listed building or land within its curtilage; iv a scheduled monument or land within its curtilage; v a safety hazard area; vi a military explosives storage area; or vii land within 3 kilometres of the perimeter of an aerodrome. Conditions AA.2 1 Where any development under Class AA is proposed, development is permitted subject to the condition that before beginning the development, the developer must apply to the local planning authority for prior approval of the authority as to— a transport and highways impacts of the development; b air traffic and defence asset impacts of the development; c contamination risks in relation to the building; d flooding risks in relation to the building; e the external appearance of the building, including— i the design and architectural features of— aa the principal elevation; and bb any side elevation that fronts a highway; and ii the impact of any works under sub-paragraph (1)(c) or (d) of Class AA; f the provision of adequate natural light in all habitable rooms of the new dwellinghouses; g impact on the amenity of the existing building and neighbouring premises including overlooking, privacy and the loss of light; h impacts of noise from any commercial premises on the intended occupiers of the new dwellinghouses; i impacts of the introduction of, or an increase in, a residential use of premises in the area on the carrying on of any trade, business or other use of land in the area; j whether, because of the siting of the building, the development will impact on a protected view identified in the Directions Relating to Protected Vistas dated 15th March 2012 issued by the Secretary of State, and the provisions of paragraph B (prior approval) of this Part apply in relation to that application. 2 In sub-paragraph (1)(h), “commercial premises” means any premises in the building or the surrounding area which are normally used for the purpose of carrying on any trade or business, and includes any premises licensed under the Licensing Act 2003 or any other place of public entertainment. 3 Any development under Class AA is permitted subject to the condition that it must be completed within a period of 3 years starting with the date prior approval is granted. 4 Any development under Class AA is permitted subject to the condition that before beginning the development, the developer must provide the local planning authority with a report for the management of the construction of the development, which sets out the proposed development hours of operation and how any adverse impact of noise, dust, vibration and traffic on occupiers of the building and adjoining owners or occupiers will be mitigated. 5 The developer must notify the local planning authority of the completion of the development as soon as reasonably practicable after completion. 6 The notification referred to in sub-paragraph (5) must be in writing and must include— a the name of the developer; b the address or location of the development; and c the date of completion. 7 Following the development, every dwellinghouse in the building must remain in use as a dwellinghouse within the meaning of Class C3 of the Schedule to the Use Classes Order and for no other purpose, except to the extent that the other purpose is ancillary to the primary use as a dwellinghouse. Class AB - new dwellinghouses on terrace buildings in commercial or mixed use Permitted development AB 1 Development consisting of works for the construction of new dwellinghouses immediately above the topmost storey on a terrace building to which sub-paragraph(2) applies, where that development comprises— a up to two additional storeys, in the case of an existing building consisting of two or more storeys; b one additional storey, in the case of an existing building consisting of one storey, together with any development under sub-paragraph (3). 2 This sub-paragraph applies to a building which is— a used for any purpose within Class A1 (shops), Class A2 (financial and professional services), Class A3 (restaurants and cafes) or Class B1(a) (offices) of the Schedule to the Use Classes Order, or as a betting office, pay day loan shop or launderette; b in a mixed use combining— i two or more uses within paragraph (a); or ii a use falling within Class C3 (dwellinghouses) of the Schedule to the Use Classes Order, together with one or more uses within paragraph (a). 3 Development consisting of any or all— a engineering operations reasonably necessary to construct the additional storeys and new dwellinghouses; b works for the replacement of existing plant or installation of additional plant on the roof of the extended building reasonably necessary to service the new dwellinghouses; c works for the construction of appropriate and safe access to and egress from the new dwellinghouses and existing premises, including means of escape from fire, via additional external doors or external staircases; d works for the construction of storage, waste or other ancillary facilities reasonably necessary to support the new dwellinghouses. Development not permitted AB.1 Development is not permitted by Class AB if— a the building was constructed before 1st July 1948 or after 5th March 2018; b on 5th March 2018 the building was in a use other than— i a use or mixed use within paragraph AB(2)(a) or (b); or ii a use falling within Class C3 of the Schedule to the Use Classes Order; c the additional storeys are constructed other than on the principal part of the building; d the floor to ceiling height of any additional storey, measured internally, would exceed the lower of— i 3 metres; or ii the floor to ceiling height, measured internally, of any storey of the principal part of the existing building; e the new dwellinghouses are not flats; f the height of the highest part of the roof of the extended building (not including plant) would be greater than 18 metres; g the height of the highest part of the roof of the extended building would exceed by more than 3.5 metres the height of the highest part of the roof of every other building in the row of terrace buildings of which it forms part (not including plant, in each case); h the height of the highest part of the roof of the extended building would exceed the height of the highest part of the roof of the existing building (not including plant, in each case) by more than— i 3.5 metres, where the existing building consists of one storey; or ii 7 metres, where the existing building consists of more than one storey; i the existing building has been enlarged by the addition of one or more storeys above the original building, whether in reliance on permission granted under this Part or otherwise; j development under Class AB(3)(a) would include the provision of visible support structures on or attached to the exterior of the building upon completion of the development; k development under Class AB(3)(a) would consist of engineering operations other than works within the existing curtilage of the building to— i strengthen existing walls; ii strengthen existing foundations; or iii install or replace water, drainage, electricity, gas or other services; l in the case of Class AB(3)(b) development there is no existing plant on the building; m in the case of Class AB(3)(b) development the height of any replaced or additional plant as measured from the lowest surface of the new roof on the principal part of the extended building would exceed the height of any existing plant as measured from the lowest surface of the existing roof on the principal part of the existing building; n development under Class AB(3)(c) would extend beyond the curtilage of the existing building; o development under Class AB(3)(d) would— i extend beyond the curtilage of the existing building; ii be situated on land forward of a wall forming the principal elevation of the existing building; or iii be situated on land forward of a wall fronting a highway and forming a side elevation of the existing building; or p the land or site on which the building is located, is or forms part of— i article 2(3) land; ii a site of special scientific interest; iii a listed building or land within its curtilage; iv a scheduled monument or land within its curtilage; v a safety hazard area; vi a military explosives storage area; or vii land within 3 kilometres of the perimeter of an aerodrome. Conditions AB.2 1 Where any development under Class AB is proposed, development is permitted subject to the condition that before beginning the development, the developer must apply to the local planning authority for prior approval of the authority as to— a transport and highways impacts of the development; b air traffic and defence asset impacts of the development; c contamination risks in relation to the building; d flooding risks in relation to the building; e the external appearance of the building, including— i the design and architectural features of — aa the principal elevation; and bb any side elevation that fronts a highway; and ii the impact of any works under paragraph AB(3)(c) or (d); f the provision of adequate natural light in all habitable rooms of the new dwellinghouses; g impact on the amenity of the existing building and neighbouring premises including overlooking, privacy and the loss of light; h impacts of noise from any commercial premises on the intended occupiers of the new dwellinghouses; i impacts of the introduction of, or an increase in, a residential use of premises in the area on the carrying on of any trade, business or other use of land in the area; j whether, because of the siting of the building, the development will impact on a protected view identified in the Directions Relating to Protected Vistas dated 15th March 2012 issued by the Secretary of State, and the provisions of paragraph B (prior approval) of this Part apply in relation to that application. 2 In sub-paragraph (1)(h), “commercial premises” means any premises in the building or the surrounding area which are normally used for the purpose of carrying on any trade or business, and includes any premises licensed under the Licensing Act 2003 or any other place of public entertainment.. 3 Any development under Class AB is permitted subject to the condition that the development must not include a window in any wall or roof slope forming a side elevation of the building. 4 Any development under Class AB is permitted subject to the condition that it must be completed within a period of 3 years starting with the date prior approval is granted. 5 Any development under Class AB is permitted subject to the condition that before beginning the development, the developer must provide the local planning authority with a report for the management of the construction of the development, which sets out the proposed development hours of operation and how any adverse impact of noise, dust, vibration and traffic on occupiers of the building and adjoining owners or occupiers will be mitigated. 6 The developer must notify the local planning authority of the completion of the development as soon as reasonably practicable after completion. 7 The notification referred to in sub-paragraph (6) must be in writing and must include— a the name of the developer; b the address or location of the development; and c the date of completion. 8 Following the development, every dwellinghouse in the building must remain in use as a dwellinghouse within the meaning of Class C3 of the Schedule to the Use Classes Order and for no other purpose, except to the extent that the other purpose is ancillary to the primary use as a dwellinghouse. Class AC - new dwellinghouses on terrace buildings in use as dwellinghouses Permitted development AC 1 Development consisting of works for the construction of new dwellinghouses immediately above the topmost storey on a terrace building in use as a single dwellinghouse within the meaning of Class C3 of the Schedule to the Use Classes Order, where the development comprises— a up to two additional storeys, in the case of an existing dwellinghouse consisting of two or more storeys; b one additional storey, in the case of an existing dwellinghouse consisting of one storey, together with any development under sub-paragraph (2). 2 Development consisting of any or all— a engineering operations reasonably necessary to construct the additional storeys and new dwellinghouses; b works for the construction of appropriate and safe access to and egress from the new and existing dwellinghouses, including means of escape from fire, via additional external doors or external staircases; c works for the construction of storage, waste or other ancillary facilities reasonably necessary to support the new dwellinghouses. Development not permitted AC.1 Development is not permitted by Class AC if— a the building was constructed before 1st July 1948 or after 5th March 2018; b on 5th March 2018 the building was in a use other than— i a use falling within Class C3 (dwellinghouses) of the Schedule to the Use Classes Order; or ii a use or mixed use within paragraph AA(2)(a) or (b) of this Part; c the additional storeys are constructed other than on the principal part of the dwellinghouse; d the floor to ceiling height of any additional storey, measured internally, would exceed the lower of— i 3 metres; or ii the floor to ceiling height, measured internally, of any storey of the principal part of the existing dwellinghouse; e the new dwellinghouses are not flats; f the height of the highest part of the roof of the extended building would be greater than 18 metres; g the height of the highest part of the roof of the extended building would exceed by more than 3.5 metres the height of the highest part of the roof of every other building in the row of terrace buildings of which it forms part; h the height of the highest part of the roof of the extended building would exceed the height of the highest part of the roof of the existing dwellinghouse by more than— i 3.5 metres, where the existing dwellinghouse consists of one storey; or ii 7 metres, where the existing dwellinghouse consists of more than one storey; i the existing dwellinghouse has been enlarged by the addition of one or more storeys above the original dwellinghouse, whether in reliance on permission granted under Class AA of Part 1 or otherwise; j development under Class AC(2)(a) would include the provision of visible support structures on or attached to the exterior of the building upon completion of the development; k development under Class AC(2)(a) would consist of engineering operations other than works within the existing curtilage of the dwellinghouse to— i strengthen existing walls; ii strengthen existing foundations; or iii install or replace water, drainage, electricity, gas or other services; l development under Class AC(2)(b) would extend beyond the curtilage of the existing dwellinghouse; m development under Class AC(2)(c) would— i extend beyond the curtilage of the existing dwellinghouse; ii be situated on land forward of a wall forming the principal elevation of the existing dwellinghouse; or iii be situated on land forward of a wall fronting a highway and forming a side elevation of the existing dwellinghouse; or n the land or site on which the dwellinghouse is located, is or forms part of— i article 2(3) land; ii a site of special scientific interest; iii a listed building or land within its curtilage; iv a scheduled monument or land within its curtilage; v a safety hazard area; vi a military explosives storage area; or vii land within 3 kilometres of the perimeter of an aerodrome. Conditions AC.2 1 Where any development under Class AC is proposed, development is permitted subject to the condition that before beginning the development, the developer must apply to the local planning authority for prior approval of the authority as to— a transport and highways impacts of the development; b air traffic and defence asset impacts of the development; c contamination risks in relation to the building; d flooding risks in relation to the building; e the external appearance of the building, including— i the design and architectural features of— aa the principal elevation; and bb any side elevation that fronts a highway; and ii the impact of any works under paragraph AC(2)(b) or (c); f the provision of adequate natural light in all habitable rooms of the new dwellinghouses; g impact on the amenity of the neighbouring premises including overlooking, privacy and the loss of light; h whether, because of the siting of the building, the development will impact on a protected view identified in the Directions Relating to Protected Vistas dated 15th March 2012 issued by the Secretary of State, and the provisions of paragraph B (prior approval) of this Part apply in relation to that application. 2 Any development under Class AC is permitted subject to the following conditions— a the materials used in any exterior work must be of a similar appearance to those used in the construction of the exterior of the existing dwellinghouse; b following the development, the roof pitch of the principal part of the building must be the same as the roof pitch of the principal part of the existing dwellinghouse; and c the development must not include a window in any wall or roof slope forming a side elevation of the dwellinghouse. 3 Any development under Class AC is permitted subject to the condition that it must be completed within a period of 3 years starting with the date prior approval is granted. 4 Any development under Class AC is permitted subject to the condition that before beginning the development, the developer must provide the local planning authority with a report for the management of the construction of the development, which sets out the proposed development hours of operation and how any adverse impact of noise, dust, vibration and traffic on occupiers of the building and adjoining owners or occupiers will be mitigated. 5 The developer must notify the local planning authority of the completion of the development as soon as reasonably practicable after completion. 6 The notification referred to in sub-paragraph (5) must be in writing and must include— a the name of the developer; b the address or location of the development; and c the date of completion. 7 Following the development, every dwellinghouse in the building must remain in use as a dwellinghouse within the meaning of Class C3 of the Schedule to the Use Classes Order and for no other purpose, except to the extent that the other purpose is ancillary to the primary use as a dwellinghouse. Class AD - new dwellinghouses on detached buildings in use as dwellinghouses Permitted development AD 1 Development consisting of works for the construction of new dwellinghouses immediately above the topmost storey on a detached building in use as a single dwellinghouse within the meaning of Class C3 of the Schedule to the Use Classes Order, where the development comprises— a up to two additional storeys, in the case of an existing dwellinghouse consisting of two or more storeys; b one additional storey, in the case of an existing dwellinghouse consisting of one storey, together with any development under sub‑paragraph (2). 2 Development consisting of any or all— a engineering operations reasonably necessary to construct the additional storeys and new dwellinghouses; b works for the construction of appropriate and safe access to and egress from the new and existing dwellinghouses, including means of escape from fire, via additional external doors or external staircases; c works for the construction of storage, waste or other ancillary facilities reasonably necessary to support the new dwellinghouses. Development not permitted AD.1 Development is not permitted by Class AD if— a the building was constructed before 1st July 1948 or after 5th March 2018; b on 5th March 2018 the building was in a use other than— i a use falling within Class C3 (dwellinghouses) of the Schedule to the Use Classes Order; or ii a use or mixed use within paragraph AA(2)(a) or (b) of this Part; c the additional storeys are constructed other than on the principal part of the dwellinghouse; d the floor to ceiling height of any additional storey, measured internally, would exceed the lower of— i 3 metres; or ii the floor to ceiling height, measured internally, of any storey of the principal part of the existing dwellinghouse; f the new dwellinghouses are not flats; g the height of the highest part of the roof of the extended building would be greater than 18 metres; h the height of the highest part of the roof of the extended building would exceed the height of the highest part of the roof of the existing dwellinghouse by more than— i 3.5 metres, where the existing dwellinghouse consists of one storey; or ii 7 metres, where the existing dwellinghouse consists of more than one storey; i the existing dwellinghouse has been enlarged by the addition of one or more storeys above the original building, whether in reliance on permission granted under Class AA of Part 1, or otherwise; j development under Class AD(2)(a) would include the provision of visible support structures on or attached to the exterior of the building upon completion of the development; k development under Class AD(2)(a) would consist of engineering operations other than works within the existing curtilage of the dwellinghouse to— i strengthen existing walls; ii strengthen existing foundations; or iii install or replace water, drainage, electricity, gas or other services; l development under Class AD(2)(b) would extend beyond the curtilage of the existing dwellinghouse; m development under Class AD(2)(c) would— i extend beyond the curtilage of the existing dwellinghouse; ii be situated on land forward of a wall forming the principal elevation of the existing dwellinghouse; or iii be situated on land forward of a wall fronting a highway and forming a side elevation of the existing dwellinghouse; or n the land or site on which the dwellinghouse is located, is or forms part of— i article 2(3) land; ii a site of special scientific interest; iii a listed building or land within its curtilage; iv a scheduled monument or land within its curtilage; v a safety hazard area; vi a military explosives storage area; or vii land within 3 kilometres of the perimeter of an aerodrome. Conditions AD.2 1 Where any development under Class AD is proposed, development is permitted subject to the condition that before beginning the development, the developer must apply to the local planning authority for prior approval of the authority as to— a transport and highways impacts of the development; b air traffic and defence asset impacts of the development; c contamination risks in relation to the building; d flooding risks in relation to the building; e the external appearance of the building, including— i the design and architectural features of — aa the principal elevation; and bb any side elevation that fronts a highway; and ii including the impact of any works under paragraph AD(2)(b) or (c); f the provision of adequate natural light in all habitable rooms of the new dwellinghouses; g impact on the amenity of the neighbouring premises including overlooking, privacy and the loss of light; h whether, because of the siting of the building, the development will impact on a protected view identified in the Directions Relating to Protected Vistas dated 15th March 2012 issued by the Secretary of State, and the provisions of paragraph B (prior approval) of this Part apply in relation to that application. 2 Any development under Class AD is permitted subject to the following conditions— a the materials used in any exterior work must be of a similar appearance to those used in the construction of the exterior of the existing dwellinghouse; b following the development, the roof pitch of the principal part of the building must be the same as the roof pitch of the principal part of the existing dwellinghouse; and c the development must not include a window in any wall or roof slope forming a side elevation of the building. 3 Any development under Class AD is permitted subject to the condition that it must be completed within a period of 3 years starting with the date prior approval is granted. 4 The developer must notify the local planning authority of the completion of the development as soon as reasonably practicable after completion. 5 The notification referred to in sub-paragraph (4) must be in writing and must include— a the name of the developer; b the address or location of the development; and c the date of completion. 6 Following the development, every dwellinghouse in the building must remain in use as a dwellinghouse within the meaning of Class C3 of the Schedule to the Use Classes Order and for no other purpose, except to the extent that the other purpose is ancillary to the primary use as a dwellinghouse. . 4 In paragraph B (procedure for applications for prior approval under Part 20)— a in sub-paragraph (2)(a)— i for “Class A” substitute “any of Classes A to AD”; ii for “paragraphs A.(a) to (d)” substitute “paragraph A(a) to (d), AA(1)(a) to (d), AB(3)(a) to (d), AC(2)(a) to (c), or AD(2)(a) to (c) (as the case may be)”; b in sub-paragraph (2)(d), for the words from “that” to the end, substitute “(that is, additional to any dwellinghouses in the existing building)”; c in sub-paragraph (2)(e), for the words from “the flats” to the end, substitute “any flats and any other premises in the existing building”; d in sub-paragraph (12)(b), for “the flats within existing block of flats” substitute “any flats and any other premises within the existing building”. 5 In paragraph C (interpretation of Part 20)— a at the end of the definition of “purpose-built” omit “and”; b after that definition insert— “row”, in relation to a terrace building, means the row of two or more terrace buildings of which it forms part, where each building in the row— shares a party wall with, or has a main wall adjoining the main wall of, the building on either side; or if it is the end of a row— in the case of a row comprising more than two buildings, it shares a party wall with, or has a main wall adjoining the main wall of, a building which fulfils the requirements of paragraph (a); or in the case of a row comprising only two buildings, it shares a party wall with, or has a main wall adjoining the main wall of, the other building in the row; ; c in the definition of “technical sites” omit “Annexe 1 of”; d after the definition of “technical sites” insert— “terrace building” means a building which is not detached. ; e the existing text becomes sub-paragraph (1), and after that sub-paragraph insert— 2 In Part 20 references to a “storey” do not include— a any storey below ground level; or b any accommodation within the roof of a building, whether comprising part of the original building or created by a subsequent addition or alteration, and accordingly, references to an “additional storey” include a storey constructed in reliance on the permission granted by this Part which replaces accommodation within the roof of the existing building. . Signed by authority of the Secretary of State for Housing, Communities and Local Government Christopher Pincher Minister of State Ministry of Housing, Communities and Local Government 20th July 2020