Class AB – New flats on terraced buildings in commercial or mixed use (shops and flats)
Class AB allows for new flats on terraced or semi-detached buildings that are commercial or commercial with flats above.
Very similar to Class AA, but this is for additional stories on a terraced or semi-detached shops and flats. The government has given the ability to add up to two storeys in the airspace above any terraced or semi-detached building that was either shops (Use Class A1), financial and professional services (Use Class A2), restaurants and cafes (Use Class A3), offices (Use Class B1(a)), betting office, payday loan shop or launderette (all sui generis) or mixed use along with residential C3 which result in shops etc. and flats above.
In other words the building could be a row of shops with nothing above in which case you can add one storey. It could be a row of shops with one or more storeys of flats above them, or shops with retail space above them. In these later to situations you can add up to two new storeys. You can go as high as 18 metres with the finished development. This can also be on part of the block, subject to a maximum additional height of 3.5m in the case of a single storey of shops etc. or 7m over surrounding roofs if more than one storey.
The building must have been constructed between 1st July 1948 and 5th March 2018 and can’t have been previously extended upwards.
One important factor is that neither the current or future flats can be C4 via Class L or Sui Generis HMOs. You are limited to C3 dwellings only. An HMO would require full planning.
Class AB permitted development right for shops and flats came into force at 9am on 31st August 2020.
See our useful table of all airspace opportunities available within the GPDO.
What was it on 5th March 2018?
The Use Class of the commercial unit must have been either in use as shops (Use Class A1), financial and professional services (Use Class A2), restaurants and cafes (Use Class A3), offices (Use Class B1a), betting office, payday loan shop or launderette (all sui generis) or mixed use along with residential C3 which result in shops etc. and flats above on 5th March 2018. If it was another use on the 5th March 2018 and has been converted since to one of the above uses, then the building will not qualify for Class AB.
What else might prevent me taking advantage?
You cannot use this permitted development right of Class AB in Article 2(3) land, SSSIs, listed buildings, scheduled monuments, safety hazard area, military explosives area or within 3 kilometres(1.86 miles) of an aerodrome. Article 2(3) land includes conservation areas.
The main requirements of Class AB is as follows:
- The additional storey(s) must be constructed on the principal part of the building
- The height of the highest part of the roof of the extended building (not including plant) can not be greater than 18m
- The floor to ceiling height of any additional storey (measured internally) can not exceed the lower of 1) 3m, or 2) the floor to ceiling height (measured internally) of any storey of the principal part of the existing building
- The height of the highest part of the roof of the extended building can not exceed the height of the highest part of the roof of the existing building (not including plant, in each case) by more than 3.5m (if the existing building consists of one storey) or 7m (if the existing building consists of more than one storey)
- The height of the highest part of the roof of the extended building can not exceed 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) by more than 3.5m
- Any engineering operations can not include the provision of visible support structures on or attached to the exterior of the building upon completion of the development
- Any engineering operations are limited to works (within the existing curtilage of the building) to strengthen existing walls or foundations, or to install or replace services
- The installation of additional plant (on the roof of the extended building) is only allowed if there is existing plant on the building
- The height of any replacement or additional plant (as measured from the lowest surface of the new roof on the principal part of the extended building) can not 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)
- Any new access to and egress from the new dwellinghouses and existing premises can not extend beyond the curtilage of the existing building
- Any new storage, waste or other ancillary facilities can not extend beyond the curtilage of the existing building
- Any new storage, waste or other ancillary facilities can not be situated on land forward of a wall that either 1) forms the principal elevation of the existing building or 2) fronts a highway and forms a side elevation of the existing building.
There a few considerations that the local authority will need to consider as part of the prior approval. These are transport & highways impacts, air traffic and defence assets, contamination, flood risk, external appearance, natural light in all habitable rooms, impacts of noise from any commercial premises on the intended occupiers of the new flats, 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, impact upon amenity space of the existing building and neighbouring ones, overlooking/privacy/loss of light, impact on a protected view identified in the Directions Relating to Protected Vistas.
Application Procedure
Class AB requires a Prior Approval application to the local authority and should be decided within 8 weeks or 56 days. You will need to supply floor plans, the number of dwellings and a list of addresses of all flats currently in the block. You will also need to submit a flood risk report if required and information on the various considerations that the local authority will need to consider. There is however no deemed consent if the decision has not been made within this period of time.
Application Form and Checklist
You can download the application form for Class AB directly from the Planning Portal here. The application should be submitted directly to your local authority as at this time it is not possible to submit via the Planning Portal. We have created a useful planning application checklist for Class AB which you can download here.
Please note that although all local authorities should be the same, some may vary within their validation process – if in doubt check with them. The application is not valid until the form is completed and the application fee of £334 for each dwellinghouse if not more than 50 dwellings, more than 50 dwellings: £16,525 + £100 for each dwelling in excess of 50 with a maximum fee: £300,000 is paid. Once this has been done the 56 days will start to count. However, remember there isn’t any deemed consent.
Full legislation
The full legislation was originally issued on 21st July 2020. There have been a few updates since and the text below is up to the date shown below . We have added in all the changes. It says…..
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 1987 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 1987 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.
(4) In relation to Class AB, “the 1987 Order” means the Use Classes Order as in force on 5th March 2018
Development not permitted
AB.1. Development is not permitted by Class AB if—
(za) the permission to use the building as a dwellinghouse has been granted only by virtue of Class MA of Part 3 of this Schedule;
(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.
Page updated: 23rd November 2021