A Planning Court decision in October 2017 raises an important issue. Whilst many conversions of buildings can rely on permitted development rights, most new build requires planning permission. But can a conversion of a building be so substantial that it instead constitutes a rebuild, requiring planning permission? The answer given by the Planning Court is: yes.

This may leave developers of an extensive conversion in a position where they face enforcement action for unauthorised development. In light of this case developers would be well-advised to carefully review with their legal advisers whether their conversion is in fact a rebuild for which they require planning permission.

The facts of the case

In Oates v Secretary of State for Communities and Local Government the claimant had carried out development to convert three poultry sheds into residential dwellings in Canterbury, Kent. Canterbury City Council (the “Council”) confirmed that no permission was needed for a change of use from office (B1) use to residential use (C3), relying on Schedule 2 Part 3 Class O to the Town and Country Planning (General Permitted Development) (England) Order 2015. Significantly that provision permits change of use from office to residential but does not (unlike some other similar provisions) permit associated alterations to the external appearance of the building.

After the development had been carried out the Council took the view that the works constituted unauthorised development. This was because “a significant amount (to put it neutrally) of further building work had been done”. The Council therefore took the view that the development constituted a rebuild rather than a conversion. The Council issued an enforcement notice alleging a breach of planning control on the basis that new buildings had been erected without planning permission. The notice required the demolition of the buildings, the removal of all material from the land, and to ‘make good’ the land underneath. Note that the last of these conditions was judged to be too vague and was deleted.

The claimant appealed on the basis that they had only made alterations to the existing buildings. The appeal was dismissed, with the inspector stating that although parts of the original buildings remained, materially new buildings had been constructed. The claimant appealed to the Planning Court.

The judgment

As the inspector had, the court applied the judgement in Hibbitt v SSCLG and Rushcliffe BC, which established that an original building need not be demolished for it to become a new building. This means that a development can be a ‘new building’ even where parts of the original building remain.

With the above point established, whether the development extended beyond a conversion and constituted a new building was a matter of fact and degree. This was a decision for the planner. This opinion could only therefore be challenged along ‘Wednesbury’ grounds, that is, where the decision was so unreasonable that no reasonable person acting reasonably could have made it. The court ruled that the inspector’s decision was based on a very careful analysis and that the decision-making process could not be criticised.

The claimant also challenged the inspector’s decision on the basis that it ignored that under s336 of the TCPA 1990, whatever remained from the original buildings still constituted “buildings” under the act. The claimant alleged that there could not therefore be a new building as the original one had always stood. The court rejected this approach as it would mean that it would never be possible for a new building to emerge from an old one, contrary to the reasoning in Hibbitt.

After rejecting these grounds, the court found that the inspector did not err in finding that the development comprised new buildings. As a result the enforcement notice was valid. This case provides a valuable reminder that the conversion of a building can be so substantial as to constitute a rebuild requiring planning permission.