Harriet Grimes
Posted on 15 Nov 2021

Planning: The pitfalls of Class Q permitted development

Class Q of the Town and Country Planning (General Permitted Development) Order 2015 ("GPDO") allows for the conversion of agricultural buildings to dwelling houses without the need for planning permission, subject to meeting certain conditions and limitations.  

The conditions set out in the GPDO are onerous. In addition, there have been several recent appeal decisions which cast light on how the GPDO rights should apply. We now look at these decisions and consider how they were applied in practice.

Evidence of agricultural use

The principal qualifying criteria under Class Q is that the building was in agricultural use on 20 March 2013. If the building was brought into agricultural use after that date, a period of 10 years must pass before development under Class Q begins.

A recent appeal against refusal of Class Q prior approval in the Derbyshire countryside failed when an inspector found limited evidence of agricultural use at the site. On the basis of photographic evidence and taking account of representations of local residents and the parish council, the inspector concluded that any previous agricultural use would have likely ceased and the permitted development right did not apply.

Extent of the works required

Under paragraph Q1(i) of Class Q, the planning authority must consider whether the required building operations are to the extent reasonably necessary for the building to function as a dwelling house.

The case of Hibbit v Secretary of State for Communities & Local Government [2016] established that if works were to go beyond a ‘conversion’ the proposal would fall beyond the permitted development right.

There are numerous appeal decisions where agricultural buildings have been held to be insubstantial to 'convert' the building. In a recent appeal in Buckinghamshire, the inspector judged that the removal of all of the existing cladding and installation of replacement cladding to all sides and the roof of the remaining steel framework went well beyond what could reasonably be described as a conversion and was not permitted development.

Listed building

Under paragraph Q1(m), development is not permitted if the building is a listed building. If a building is listed in its own right, the situation is straight forward, however difficulties can arise if there is a question mark over whether the agricultural building(s) form part of the curtilage of a listed building.

Prior approval under Class Q was refused in the open countryside in Essex because two of the buildings were deemed to be curtilage listed. The agricultural buildings were located near to a grade II listed manor house. They were part of the same farmyard, in the same ownership and had a close physical and functional relationship through their associated use, access, proximity and arrangement typical of many farmsteads. The inspector held that the subsequent separation of the farm buildings from the manor house, post listing, did not alter their listed status and therefore permission for their conversion was required.

Location and siting

Paragraph Q.2.(1) of Class Q lists conditions under which the developer must apply to the local planning authority for a determination as to whether prior approval will be required as to the impact of the development on various matters.

The condition set out at Q.2(1)(e) relates to whether the location or siting of the building makes it otherwise impractical or undesirable for the building to change from agricultural use to a dwelling house.

In a recently dismissed appeal in Mid Devon, the inspector held that whilst there were no objections from the Highway Authority, the lack of a suitable access to the public highway meant the location and siting of the building (in a field of open grassland) would be impractical and undesirable for a residential dwelling.

In another appeal in the City of Bradford Metropolitan, it was held that the introduction of a dwelling in an isolated location would cause detriment to the landscape and the character of the area.


Whilst numerous agricultural buildings are gaining prior approval for conversion under Class Q, the process is not without its challenges.

Some planning authorities have moved to a far more restrictive stance, particularly in relation to certain buildings, such as steel portal framed. There generally seems to be patchwork of different practice in different authorities and any application under Class Q should be planned carefully to give it the best chance of success.