With statistics showing that more than 50,000 buildings were converted for domestic use between 2014 and 2015 and yet only 226 barn conversions were completed under the permitted developments rights, planning lawyer and author of the Practical Guide to Permitted Changes of Use, Martin Goodall, looks at the common problems faced by those looking to convert.

The General Permitted Development Order was amended in 2014 to allow the residential conversion of agricultural buildings as permitted development in place of the previous requirement for planning permission (which was often refused), although such conversions are still subject to a “prior approval” procedure. Some local planning authorities, however, have sought to resist this type of permitted development on various grounds, and there have been numerous planning appeals and one or two court battles over these developments.

There are various qualifying criteria, exclusions, limitations and conditions that apply to this type of development, and these have sometimes proved to be a stumbling block for applicants seeking prior approval of residential conversions. One issue that has always been a problem, but has recently come to the fore as the result of a High Court judgment, is the ‘convertibility’ of the building. In principle, a building can include various types of structure of unconventional and, perhaps in some cases, rather insubstantial construction. However, the works permitted in the residential conversion of an agricultural building are restricted to what is reasonably necessary for the building to function as a dwelling, and any partial demolition and reconstruction must be limited to the extent reasonably necessary to carry out the permitted building operations.

This imposes a practical constraint on the convertibility of some buildings. Works that amount to substantial demolition and reconstruction or replacement of the existing fabric would go beyond what is allowed. The Government amended its online Planning Practice Guidance in March 2015, confirming that it is not its intention to permit the construction of new structural elements for the building. The judgment in Hibbitt v SSCLG has endorsed this approach to the structural issue.

However, some of the other reasons that local planning authorities have given for refusing prior approval of barn conversions have been overruled on appeal. One of these is the ‘sustainability’ of such a development in a rural location (in terms of access and transport). This is a reason that frequently justifies the refusal of planning permission for development in the open countryside, but it cannot be used to justify a refusal of prior approval for the residential conversion of an agricultural building as permitted development. The Government made this clear in its revised online Planning Practice Guidance in March 2015. A recent challenge to the legality of this advice by a local authority in Hertfordshire has been dismissed by the High Court, in East Herts DC v SSCLG. The ministerial guidance emphasises that this permitted development right does not apply a test of sustainability of location, because many agricultural buildings will not be in village settlements and may not be able to rely on public transport for their daily needs.

Instead, the council can consider whether the location and siting of the building would make it impractical or undesirable to change its use to a house. The guidance explains that “impractical” indicates that the location and siting would “not be sensible or realistic”, and the word “undesirable” suggests that it would be “harmful or objectionable”. When considering whether it is appropriate for the change of use to take place in a particular location, an authority should start from the premise that the permitted development right already grants planning permission, subject to the prior approval requirements.

A refusal of prior approval is not justified simply because an agricultural building is in a location where the council would not normally grant planning permission for a new dwelling. When a council considers location and siting, it should not therefore be applying tests from the National Planning Policy Framework, except to the extent that these are strictly relevant to the specific matters that actually require prior approval. So, for example, factors such as whether the property is for a rural worker, or whether the design is of exceptional quality or innovative, are unlikely to be relevant.

It is absolutely essential to comply strictly with the detailed (and admittedly complex) rules applying to the permitted development rights for the residential conversion of agricultural buildings, and with the procedure for their prior approval.