Planning circular 2/2015: non-domestic permitted development rights - consolidated circular - updated 2021

This circular consolidates, updates and replaces certain previous guidance on non-domestic Permitted Development Rights (PDRs).

This document is part of a collection

Annex H

Conversion of Agricultural and Forestry Buildings to Residential Use


1. Classes 18B and 22A allow the change of use, and certain building operations to effect the change of use, from use as an agricultural or forestry building respectively to use as a dwelling.

2. Building operations are only permitted by classes 18B and 22A to the extent that they are reasonably necessary to convert the existing building to use as a dwelling. They are limited to:

  • the installation or replacement of doors, windows, roofs and exterior walls
  • the installation or replacement of water, drainage, sewerage, electricity, gas or other services
  • partial demolition to the extent necessary to carry out the installation or replacement of doors, windows, roofs and exterior walls; and
  • the provision of access to the dwelling and of a hard surface for parking of vehicles ancillary to the enjoyment of the dwelling.

3. The installation or replacement of doors, windows, roofs and exterior walls or of water, drainage, sewerage, electricity, gas or other services is only permitted to the extent reasonably necessary for the building to function as a dwelling.

4. Consideration of what works are 'reasonably necessary' will be a matter of fact and degree in any individual case and should be considered in accordance with the various restrictions set out in the respective classes.

5. The purpose of these provisions is to support the conversion of buildings: they do not allow for a complete demolition and erection of a new building on the footprint of the existing building. Nor are they intended to permit such extensive demolition and rebuilding works as to create what, in effect, would constitute a new building. The existing building needs to be capable of being converted to residential use for classes 18B and 22A to apply.

6. The partial demolition of any building should therefore be minimised and generally confined to work essential to make the building suitable for use as a dwelling. While partial demolition is only permitted to the extent it is reasonably necessary to carry out the operations specified above, it is recognised that in some cases doing so could enhance the design and appearance of the proposed conversion. It should also be noted that (with the exception of guttering and pipes for drainage or sewerage, flues and aerials) development carried out under class 18B or 22A may not have the effect of extending the external dimensions of the building at any given point. For the avoidance of doubt, demolition of the existing building and erection of a replacement does not fall under this PDR and will require a planning application.

7. Both classes also permit the provision of access to the dwelling and of a hard surface for vehicle parking incidental to the enjoyment of the dwelling. Consideration should be given to the utilisation of existing access routes and hard standing wherever possible.

8. The change of use includes the land within the curtilage of the building.

9. Any consent granted under these permitted development rights do not affect any obligations to comply with other legislative requirements such as, but not restricted to, building standards. Where dwellings are to be connected to private water or sewerage supplies are to be undertaken, appropriate permissions should be sought[33]. More information on private water supplies may be sought from the relevant local authority and the Scottish Government's website:


10. There are a number of limitations common to both classes.

11. Development is only permitted if the use of the existing building on 4 November 2019, or if not used on that date the most recent use of the building before that date, was:

  • For class 18B, as a building solely for used for an agricultural purpose as part of an agricultural unit, or;
  • For class 22A, as a building solely used for the purposes of forestry.

12. Development is not permitted if the building is or was constructed after 4 November 2019. This date is specified because the Scottish Government published its intention to take forward PDR for conversion of agricultural buildings on 5 November 2019. This cut-off is intended to prevent situations where an agricultural or forestry building could be constructed (including under the provisions of classes 18 or 22 (see Annex E)) and, within a short period following construction, subsequently be removed from such use and converted to a residential use under class 18B or 22A.

13. The cumulative number of separate residential units that can be developed by virtue of these classes is restricted to a maximum of five. For the purposes of class 18B the cumulative total applies to a building or buildings on the "original" agricultural unit, which is defined as the agricultural unit which the building formed part of on 4 November 2019. For class 22A, where there is no forestry equivalent of an agricultural unit, the maximum of five relates to the total number of residential units within an individual building.

14. Both classes permit the change of use of a single building to one or more separate residential units contained within a building. Neither class permits the partial change of use of a building creating a mixed use of the resulting building.

15. The total floor space of any individual residential unit developed under the provisions of either class cannot exceed 150 square metres. It should be borne in mind that partial change of use of a building would not be permitted under either class; a building greater than 150 square metres could not be converted into a single residential unit but could accommodate more than one residential unit of 150 square metres or smaller each.

16. The permitted development rights set out in classes 18B and 22A do not apply to listed buildings, nor do they apply to buildings situated on croft land[34]. Furthermore, the permitted development rights do not apply to development within:

  • The curtilage of a listed building,
  • A site of archaeological interest,
  • A safety hazard area, or
  • A military explosives storage area.

Interaction with other permitted development rights

17. A number of the permitted development rights generally available to householders under part 1 of the Schedule to the GPDO do not apply to dwellings created by virtue of class 18B or 22A. The following permitted development rights do not apply, meaning that a planning application would need to be made and express consent granted for any such works:

  • Class 1A (Single storey ground floor extensions),
  • Class 1B (ground floor extensions of more than one storey),
  • Class 1C (installation of a porch),
  • Class 1D (enlargement of the roof),
  • Class 3A (ancillary buildings – sheds, garages, etc),
  • Class 3D (decking and raised platforms),

Prior notification and approval

18. Anyone who wants to carry out development under either class 18B or class 22A provisions is required to apply to the planning authority for a determination as to whether the prior approval of the authority is required - this is a condition of the planning permission granted under these provisions. This is referred to as 'prior notification'. The prior notification submitted to the planning authority must be accompanied by:

  • A written description of the development, including a description of any building operations and materials to be used
  • A scaled plan showing the location of the development
  • Any other scaled plans and drawings as are necessary to describe the development
  • Any fee to be paid

19. Applicants should be aware that prior notification/approval must be sought before any work has commenced. If any development for which prior notification is required is commenced before submitting the prior notification, or where prior approval is required, before that approval is issued, the permitted development rights do not apply and a planning application is required instead.

20. The change of use under either class extends to the land within the curtilage of the building that is the subject of the application. To enable the planning authority to determine the prior notification (and if required, consider prior approval), scaled plans and drawings describing the development should clearly indicate the extent of the curtilage associated with the building. Similarly the plans should clearly indicate any proposed access and areas of hard standing and the location of any proposed septic tanks and other services.

21. The prior approval procedure provides planning authorities with a means of regulating, where necessary, important aspects of new development for which full planning permission is not required by virtue of the GPDO. Provided all the GPDO requirements are met, the principle of whether the development should be permitted is not for consideration. Those matters which the planning authority may consider in determining any requirement for prior approval are:

  • The design or external appearance of the building
  • The provision of adequate natural light in all habitable rooms of the building
  • The impacts of the proposed development on transport
  • Access to the dwelling
  • The impacts of noise on residents or occupiers of the building if used as a dwelling
  • Risks to occupiers of the proposed dwelling from contamination from the site
  • The risk of flooding of the site.

22. To enable the planning authority to reach a view on these matters, it may – depending on the location and nature of the proposed conversion – be in the developer's interest to provide supporting information that goes beyond the minimum set out at paragraph 18. This could include, but is not restricted to, an agricultural holding number, contaminated land survey, flood risk assessment or noise assessment. In the absence of sufficient information to reach a view on the prior notification application, prior approval may be delayed or refused. Applicants are therefore encouraged to discuss the likely provision of information prior to the submission of a prior notification.

23. Applicants are encouraged to consider providing such information at the initial notification stage to enable planning authorities to consider such matters as early in the process as possible and to minimise the potential requirement for applications to be subject to prior approval.

24. Upon receipt of a prior notification, the planning authority has 28 days to decide whether or not their prior approval is required. If no indication that prior approval is required is received within the 28 day period, the development permitted by the class may proceed provided that the development is in accordance with the details submitted with the application.

25. Where the authority gives notice that their prior approval is required, the development cannot proceed unless and until that approval is given. It is therefore in the developer's own interests to submit the above details and any relevant supporting information as soon as possible. Doing so will assist the planning authority in reaching a view as to the need for prior approval and – subject to that – whether or not prior approval can be granted. If the developer proceeds without submitting details or without, or in contravention of, the authority's prior approval (if required) the normal enforcement measures would be available to the authority as it deems appropriate in the circumstances of any particular case.

26. Consideration of natural light is intended to avoid the provision of dwellings whose habitable rooms (i.e. bedrooms and living rooms) have no windows or are likely to be unreasonably dark. This should in most cases be apparent from the description of development and accompanying drawings. Although this will be a matter of planning judgement rather than technical compliance, planning authorities may wish to seek views from colleagues in building standards in this regard.

27. As noted above, a number of the conditions and limitations that apply to class 18B (relate to the agricultural unit within which the building is located (e.g. the cumulative maximum number of dwellings that may be developed). Accordingly, in relation to prior notifications under class 18B, the provision of the relevant agricultural holding number by the developer will assist in the identification of the site and help the planning authority to determine whether a proposal complies with relevant limitations.

28. Subject to the normal criteria governing their use - and insofar as they relate to the matters specified in class 18B and 22A - conditions may be attached to the grant of prior approval. Similarly, consideration may be given to the use of planning obligations or other legal agreements, subject to the relevant tests in circular 3/2012. Matters which are not relevant to prior approval decisions under class 18B and 22A (e.g. provision of education facilities) should not be the subject of conditions or planning obligations. In operating these controls, planning authorities should always have full regard to the need to avoid imposing any unnecessary or excessively costly requirements; and to the normal considerations of reasonableness.

Efficient Handling of Prior Notifications and Details Submitted for Approval

29. The Scottish Ministers attach great importance to the prompt and efficient handling of prior notifications and any subsequent submissions of details for approval under the provisions of the GPDO. Delegation of decisions to officers will help to achieve prompt and efficient handling, and should be extended as far as possible. It is essential that authorities acknowledge receipt of each prior notification, giving the date on which it was received.

30. Where the authority does not propose to require the submission of details it should not merely wait for the 28 days to expire but should inform the developer as soon as possible, to avoid any uncertainty and possible delay. Where the authority does decide prior approval is required, it should write to the developer as soon as possible stating clearly and simply exactly what, if any, further details are needed. Care should be taken not to request more information than is absolutely necessary.

Records of Notifications

31. Although there is no statutory requirement to do so, planning authorities should keep records of such notifications

Completion of development

32. Where prior approval is not required the development must be carried out in accordance with the plans and description submitted to the planning authority.

33. Where prior approval has been required and granted, the development must be carried out in accordance with the details approved.

34. In all cases, the development is to be carried out within three years of the date from which all approvals have been issued, or the date on which the 28 day period expired if no decision was issued before that date.



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