Piggery to penthouse: permitted development prohibited

Although not technically a penthouse, a recent case concerning the conversion of a piggery into a dwelling house merits attention, as it raises the familiar question of whether planning permission is actually required. This appeal (reference APP/V2653/W/19/3239194) concerned two different exceptions to the requirement to obtain planning permission. The first was the possibility that the works fell under Class Q of the Town and Country Planning (General Permitted Development) (England) Order 2015 ("GPDO"). The second was the suggestion that the works fell outside the definition of 'development' in section 55(2)(a) of the Town and Country Planning Act 1990 ("the 1990 Act"). However in this case the piggery conversion was found to satisfy neither.

By way of background, the original piggery buildings were constructed from low breeze block and wooden cladding walls with a corrugated pitched gable roof. There was an opening on each gable end wall and small low-level openings along the side elevation. Internally there was a concrete floor on which sat wooden props that partially supported the wooden frame of the roof. In converting the units into a dwelling, a number of works were proposed. These included staining and replacing existing timber boards on the walls, the replacement of the asbestos concrete roof, and the creation and installation of new windows and doors. The supporting statement and appeal statement also suggested the alteration but retention of internal props, underpinning of existing foundations and the raising of the entire internal floor slab.

It was the Appellant's case that the works proposed either fell within Class Q of the GPDO (and were therefore permitted development) or else were internal works only so fell outside the definition of 'development' in s.55(2)(a) of the 1990 Act (and did not therefore require planning permission in any event).

It is worth considering Class Q is a little detail here, as it highlights the deceptive complexity of the GPDO. Planning permission for those activities listed in the GPDO can be 'deemed', the consequence being that an application for planning permission need not be submitted.

Class Q(a) of Part 3, Schedule 2 covers the change of use of an agricultural building (and any land within its curtilage) to a dwellinghouse. Class Q(b) covers those building operations reasonably necessary to convert that building to a dwellinghouse. On the face of it, therefore, it seems that the piggery conversion should have been covered by Class Q. However this is not the end of the story. Paragraph Q.1(i) then sets out those operational works allowed under Class Q. These include matters such as the installation of windows, doors, roofs or exterior walls, water, drainage, or other services. It even extends to partial demolition if reasonably necessary to allow these works. However it has its limitations. The Inspector made reference to Planning Practice Guidance, when is permission required? which (at paragraph 13-105-20180615) explains that Class Q assumes the agricultural building is already capable of functioning as a dwelling. It is not intended to facilitate building works that go beyond what is reasonably necessary for the conversion of the building to residential use. The Inspector considered the various works being undertaken. Some (staining and replacing timber for example) were found to be reasonably necessary for the building to function as a dwelling, and were therefore permitted operations under Q.1(i). However, the underpinning works required did not fall under paragraph Q.1(i) or (ii).

What then of these works? It was the Appellant's position that, even if these were not permitted development under Part Q, they still did not require planning permission. This was because these were internal only and were therefore exempt from the definition of 'development' under s.55(2)(a) of the 1990 Act. However, the Inspector was unconvinced. He found that the works were likely to be significant and involve considerable rebuilding (including work under the external walls). They were not, therefore restricted to the interior of the building. As such they went beyond the definition of 'maintenance, improvement or other alteration' that would allow them to fall under the s.55(2)(a) 1990 Act exemption.

For this reason neither permitted development rights nor an exception from the definition of development applied, and planning permission was required.

This article is for general guidance only. It provides useful information in a concise form. Action should not be taken without obtaining specific legal advice.