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When is an outbuilding an extension?

Roderick Morton • Sep 19, 2024

In the recent case of Warwick DC v SSLUGC and others [2022] EWHC 2145 (Admin), the High Court had to consider whether a detached garden room could be an extension for the purposes of the exceptions to inappropriate development in the Green Belt (currently at NPPF 154(c)).


The owners of a property in a village in Warwickshire sought permission to demolish a 10sqm existing derelict structure and replace it with a 16sqm garden room/home office. Both the existing structure and the proposed new outbuilding were detached from the main house, sitting some 20m from the house. The property was in the Green Belt. 


Permission was refused. Development in the Green Belt is inappropriate unless it falls within one of the exceptions set out at NPPF.  Permission was refused because, while the new outbuilding was a replacement building, it was materially larger than the previous structure and therefore not within 154(d). Its status as an extension within 154(c) was not considered.  It was therefore inappropriate and there were no very special circumstances to outweigh the harm.


An appeal was made. At appeal, the owners argued, amongst other things, that it was an extension within 154(c). 


The Inspector allowed the appeal and granted permission. She agreed that the development was materially bigger, excluding 154(d). But she decided that it was an extension within 154(c) because it was a “normal domestic adjunct” to the main house, within a group of buildings relatively close to the main house and used for purposes related to the main house. The LPA appealed to the High Court.


Two points were before the High Court. First, was the interpretation of the words “the extension of a building” within 154(c) a matter of law for the court to decide or a matter of fact and degree for the decision maker? Second, was a detached outbuilding an extension within the 154(c) exception?


On the first question, the court held that the interpretation of planning policy was a question of law and was for the court. 


On the second, there was case law, particularly Sevenoaks DC v SSE and another [1997] EWHC 1012 (Admin), in support of extensions including detached outbuildings. That case law, the LPA said, was no longer applicable to current guidance. PPG2, in force when Sevenoaks was decided, used the words “extension of existing dwellings”, rather than “extension of a building” as used in NPPF 154(c). The court agreed that it was not safe to assume a simple read across or to assume that “dwelling” was the same as “building”.


However, the court found there was merit in PINS’ argument that, if 154(c) were interpreted restrictively, then the NPPF would have restricted the scope for extensions in the Green Belt. The purpose of the relevant paragraphs had been to widen the possibility of extensions (ie beyond dwellings to eg commercial buildings), not to restrict it. That was a reason to favour a less restrictive interpretation. 


The court accepted that a “normal domestic adjunct”, such as a garage or other outbuilding, could be physically separate from the main building. It noted that an extension would itself be a new “building” given the definition of “building” in the TCPA. It noted that some detached outbuildings had less impact than an attached extension; a focus on whether the extension was attached or not therefore had potential for some arbitrary results which did not further the purposes of the Green Belt. 


The court concluded that, in isolation, the language in NPPF 154(c) seemed to require an extension to be attached. However, in the round, there were other factors which pointed to a less restrictive definition which accorded with the content and purpose of the Green Belt treatment in the NPPF.  The inspector had therefore interpreted the paragraph properly and the appeal would be dismissed.


By way of comment, to some extent this decision just represents “business as usual”. It confirms that “extension of a building” in NPPF 154(c) can include outbuildings which are normal domestic adjuncts to the building; in that respect, the differences between the NPPF and PPG2 have not affected policy. 


That said, it is not the obvious meaning of “extension”, as the court acknowledged. It is not the meaning used in the GPDO where extensions are within Class A and detached outbuildings are within the less restrictive Class E and there are cases about sham detachment. It is not even the meaning used consistently in other parts of the NPPF. 



The case is restricted to interpretation of a particular part of the NPPF. It would be a mistake to read it across into other legislation.

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3 more years of Diddly Squat

by Roderick Morton • 28 Jun, 2023
Given its portrayal of the planning system so far, it is almost a given that season 3 of Clarkson’s Farm will not accurately present the detail of the Diddly Squat appeal decision. Here is our take. The decision is here. In summary, the LPA won almost all of the enforcement points. But simply being Jeremy Clarkson is apparently a material consideration which alters the planning balance! While he is popular, his celebrity is such that his farm shop will create significant problems beyond those of an ordinary farm shop and the inspector decided that these are problems which have already been accepted in granting his existing permission. Fewer of the harms to the AONB can therefore be attributed to the additional elements of the use. And these harms are outweighed by the economic benefits, benefits which are a result of his celebrity. So permission was granted for his farm shop and café and the associated parking and toilets. Clarkson’s popularity will be re-assessed in 3 years as the permission is time limited. Perhaps the inspector knows something we don’t. As viewers will know, Clarkson’s Farm operates in open countryside in an AONB. As well as agriculture, it has diversified to include a farm shop and a café in a lambing barn. The business tried to open a restaurant in a converted barn located some distance from the shop. The site is obviously used as a filming location. The business has proved popular and it now has significant parking and highway problems. The farm shop (with limited parking) has permission, the construction of the lambing barn (but not its use) has permission and there is permission for limited filming. The council enforced against the material change of use of the land to a mixed agricultural and leisure attraction use, comprising café, restaurant, gift/farm shop, parking and lavatory facilities. The notice was appealed. The appellant also sought (and was refused) permission for additional parking, access, storage and landscaping. This appeal was heard alongside the enforcement appeal. The inspector dealt first with the planning unit. The appellant alleged that there were three separate planning units (shop, café, restaurant), with each having a separate primary use. The council had enforced against a single unit in a mixed use. The inspector took into account that the shop/café was in a different ownership to the farm and that it had its own permission. But its activities clearly spilled out of the permitted area, extending to the proposed restaurant and the wider parking areas. The restaurant used the same parking as the shop. These were fenced/walled off from the remainder of the farm. He concluded that there was a single planning unit. As for the use of that planning unit, the inspector took issue with several items listed by the council. “Gift shop” was too ambiguous; a shop is a shop. Similarly, while visitors no doubt came for the experience, the business was not a “leisure attraction”. A leisure attraction required, said the inspector, something which the customer might be expected to pay for. There was no entrance fee here, just a shop and café. (It appears that the inspector was also concerned that any permission for a “leisure attraction” would create a very wide lawful use.) Nevertheless, there were several primary uses in a single unit so the development was a mixed use, in this case a “mixed use comprising agriculture, café, restaurant, farm shop, parking, lavatory facilities.” This put paid to the ground (b) and (c) challenges. The challenge was that the restaurant was a separate planning unit. As it was in the curtilage of the lawful farm shop, the appellant said that Class R permitted a change of use to a flexible use including a restaurant. In the light of his conclusion on the planning unit, the inspector rejected this. He said he would have rejected the Class R argument anyway as the restaurant was not clearly within the curtilage of the farm shop. The remainder of the uses cited in the notice were also challenged on the grounds that they were ancillary to the lawful farm shop use and not primary uses. The inspector concluded that, as the restaurant resulted in a mixed use, there had been a material change of use so it was irrelevant whether the other items were ancillary. As an aside, viewers of the series will recall the scripted glee with which the appellant came up with the “PD loophole” for his restaurant. It is fitting, therefore, that it was the restaurant which was the primary reason the breach was upheld. The inspector nevertheless looked at the extent to which the various alleged ancillary elements (other than the restaurant) were part of the lawful use prior to the breach. This was relevant to the fallback but also to what the extent of the material change of use truly was. He identified that the question was whether any of the elements represented a change in the character of the use. The inspector found that the level or vehicle traffic and parking went far beyond that for which permission had been given. And that the lambing shed was clearly not “by any stretch of reasonableness” being used for the purpose for which it was given permission. Even the toilet facilities went beyond what would be expected for the permitted farm shop. This was not intensification, it was a material change in the character of the use. The LPA even won the merits arguments on ground (a). The number of visitors, the traffic and parking problems, the outdoor seating, catering van and toilets clearly had an adverse effect on the AONB. The parking and landscaping proposed under the s78 application would have a similar effect. This had great weight. In the end though, permission was granted for the mixed use, including the use of the lambing shed as a café and the enforced against parking and toilets. Permission was granted under the s78 appeal for altered parking, storage and landscaping. Only the restaurant was refused. The inspector found that the parking would alleviate the current parking situation and highway safety even though it would not provide a complete solution. He accepted that a number of local suppliers benefited from trading arrangements with the shop and that the shop contributed to the local economy. He accepted that diversification was to be supported. These considerations also had great weight. Key to the decision, though, was the fact that permission had been granted, not just for a farm shop, but for a celebrity’s farm shop. Even if there was no café or restaurant, the popularity of the appellant was such that people would continue to visit the shop in numbers. This reduced to moderate the harm to the AONB caused by the new elements of the use because the permitted use already resulted in significant harm. The appellant’s celebrity might wane. In which case, the weight of the considerations in favour of the development would wane. The permission granted was therefore time limited to 36 months. The decision is well reasoned and fairly logical. The inspector did not say that the character of the use already permitted varied with the identity of the user. But the result seems to imply that the harms associated with the use could vary and that the LPA had accepted them all in granting permission. Yet it is difficult to think that the LPA could successfully have imposed conditions on the farm shop based on the identity of the applicant. The result is therefore troubling.

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Chesterton v Wokingham

by Roderick Morton • 20 Jun, 2022
This article was first published in the NAPE newsletter of August 2018. Case report - Chesterton vs Wokingham BC [1] – s70C TCPA 1990 The High Court recently had another chance to consider the scope of s70C TCPA 1990 and took that opportunity to further restrict the judgment in R(Deep Banghard) vs Bedford Borough Council [2] to its facts. Our article on Deep Banghard was published in the NAPE November 2017 newsletter. S70C enables LPAs to decline to determine a planning application where to grant permission would involve granting permission for the whole or any part of the matters specified in an enforcement notice. The section was intended to stop appellants using strategic planning applications to delay effective enforcement. In Chesterton vs Wokingham BC, the appellant was the owner of a very nice spread on the banks of the Thames at Henley which was occupied by its main director. The land is designated green belt, it is in a conservation area and in a prominent location. As well as the main house, there is a 2 storey garage and 2 storey boathouse which were connected by a single storey storage building with a terrace on its roof. The built forms of the garage and boathouse were in line with planning permissions but their linking by the storage building meant that their permissions could not be said to have been implemented. The appellant applied for retrospective permission for the structure as built in May 2016 and the council served an enforcement notice in June 2016 against the whole structure. The permission application was refused and the enforcement notice was upheld on appeal on the basis that the size, scale and massing meant that it was inappropriate development in the greenbelt context. While complete demolition had been sought, the inspector altered the notice under ground (f) to require the storage building to be demolished and the rest of the structure brought into line with the extant permissions. Time to comply was extended. Rather than complying, the appellant lodged a further application shortly before the expiry of the compliance period seeking permission for a balcony linking the boathouse and garage. The council declined to determine the application on the basis that it related to matters specified in the enforcement notice. The balcony incorporated elements of the existing store roof. The appellant sought judicial review of the council’s decision. The judgement contains an interesting review of the purpose of s70C and its related provision, 174(2A), which prevents the ground (a) appeal of an enforcement notice which is issued after a planning application has been made for the matters specified in the enforcement notice. The logic of the two provisions is not to prevent the merits of an unauthorised development being considered at all but rather to ensure that they are considered only once, the proverbial “one bite at the cherry”. In the Deep Banghard case, the council was prevented from declining an application for retention and storage use of a dwelling building under s70C on the basis that the inspector had already ruled that the permission sought under ground (a) in the enforcement appeal (ie retention as storage) was not something he could decide within the limits of s174(2)(a) as it was not a matter set out in the enforcement notice. Judge Nathalie Levien QC decided that all developers were allowed one chance to have the planning merits of a proposal considered, one “bite at the cherry”. Banghard has already been significantly restricted by Gilbart J in R (Smith) vs Basildon Borough Council [3] . In Chesterton, Martin Rodgers QC sitting as a deputy judge noted the breadth of the wording of s70C which allowed LPAs a discretion to decline to determine where the application related to the whole or any part of the matters specified in the enforcement notice and noted that these reflected the breadth of the basis for the ground (a) appeal. It was not necessary, he said, that there is complete overlap between the EN breach and the planning application before s70C is engaged. The appellant relied on Banghard where it was suggested that anything more than minor differences would mean that the EN and the PP application related to different matters. The judge rejected this; so long as “any part” (beyond deminimis) of the application related to the same matters as the EN, it could be declined under s70C. Of course, whether it should be declined was a planning judgement and no doubt the differences were relevant to that judgment Further, the “one bite at the cherry” doctrine in Banghard was qualified in the sense that if the applicant had already had the chance to have the merits of his planning application considered at the enforcement appeal but had failed to take that chance, it was reasonable to decline to determine the planning application. In this case, the appellant could have raised its current scheme as an alternative under ground (f) in the enforcement appeal. Its failure to do so counted against it. This seems a little harsh as the work required to get from the “as built” storage building to the balcony proposal was not insubstantial and it is difficult to see that it would have been a winning approach under ground (f). It seems likely that we will see further litigation on the extent to which theoretical possibilities under ground (f) should be sufficient to engage s70C. The “whole or any part of” test for appeals under ground (a) is a minefield on which inspectors are not consistent and on which there are some significant court judgments For instance, the inspector in Banghard rightly held that an alternative storage use for a building was not “part of” the dwelling which the enforcement notice alleged had been created. Other inspectors have reached wholly different conclusions focusing on the built form and ignoring the use. If the s70C power is to stand or fall on the “whole or any part of” test, more consistency is required and it seems likely that we may see another spate of litigation on this aspect. LPAs must also bear in mind that the s70C power is a discretionary one and the question of whether an application covers the whole or part of the matters set out in an enforcement notice is a matter which requires the exercise of planning judgment, rather than an administrative stroke of the pen. [1] Chesterton Commercial (Bucks) Limited vs Wokingham DC [2018] EWHC 1795 (Admin) [2] R (Deep Banghard) vs Bedford Borough Council [2017] EWHC 2391 (Admin) [3] R (Smith) vs Basildon Borough Council [2017] EWHC 2696 (Admin)
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