THE LONDON BOROUGH OF BRENT v SECRETARY OF STATE FOR LEVELLING UP, HOUSING AND COMMUNITIES & Anor

The Appellant, the London Borough of Brent (“LBB”), appeals under section 289 of the Town and Country Planning Act 1990 (“the 1990 Act”) against the decision of an Inspector appointed by the First Respondent (“the Secretary of State”) dated 24 August 2021 (“the Decision”). The Decision quashed an enforcement notice issued by LBB as the local planning authority on 11 December 2019, in respect of a terraced house at 51 Nutfield Road, London (“the Property”). The Second Respondent (“Mr Rothchild”) is the current owner of the Property.

LBB contends that the Inspector erred in law in concluding that a single storey extension to the Property was permitted development within the meaning of the Town and Country (General Permitted Development) (England) Order 2015 (SI 2015/596), referred to below as “the GPDO”, or as “the GPDO 2015” where it is necessary to distinguish it from its predecessors.

By letters to the Court dated 18 October 2021 and 10 November 2021, the Secretary of State informed the Court that he did not intend to defend the appeal, as he accepted that the Inspector had erred in law in the Decision. He has therefore taken no further part in proceedings. However, Mr Rothchild resists the appeal in full.

The main issue between the parties concerns whether the Inspector was right to proceed on the basis that a dwellinghouse in use as a “house in multiple occupation” (“HMO”) within the meaning of Use Class C4 of the Town and Country Planning (Use Classes) Order 1987 (SI 1986/764) (“the Use Classes Order”) is necessarily also a “dwellinghouse” within the meaning of the GPDO. Use Class C4 concerns “Use of a dwellinghouse by not more than six residents as [an HMO]”. Class A of Part 1 of Schedule 2 of the GPDO grants planning permission for “the enlargement, improvement or other alteration of a dwellinghouse”, subject to various conditions and limitations.

There is also a second issue, which concerns whether, if the Premises did enjoy permitted development rights as a dwellinghouse, the Inspector erred in law by failing to consider whether the extension was in fact built in accordance with information previously provided to LBB, as it was required to be. Dr Bowes submits that the Inspector was bound to investigate this matter, even though LBB raised no such issue before the Inspector, and that he erred in law in failing to do so. Mr Mackenzie submits that the Inspector was not required to consider the issue at all, in the absence of any objection by LBB to that effect.

Permission to appeal was granted by Lang J on 7 December 2021.

By section 55(1) of the 1990 Act, “development” is defined to include “building operations”, and the making of any “material change in the use” of buildings. “Building operations” are further defined to include “structural alterations of or additions to buildings”: section 55(1A).

Section 55(2) provides that certain operations or uses of land shall not be taken for the purposes of the Act to involve “development” of the land, including “(f) in the case of buildings or other land which are used for a purpose of any class specified in an order made by the Secretary of State under this section, the use of the buildings or other land or, subject to the provisions of the order, of any part of the buildings or the other land, for any other purpose of the same class.”

By section 57(1), planning permission is required for the carrying out of any development of land. By section 58(1), planning permission may be granted (amongst other means) by a development order. Section 59 empowers the Secretary of State to make a development order for the granting of planning permission, and provides that such an order may itself grant planning permission for development specified in the order or for development of any class specified.

Section 171A(1) provides that for the purposes of the Act, carrying out development without the required planning permission constitutes a breach of planning control. Section 172(1) provides that the local planning authority may issue an enforcement notice where it appears to them that there has been a breach of planning control, and that it is expedient to issue the notice. Section 174(1) provides that a person having an interest in the land to which an enforcement notice relates may appeal to the Secretary of State against the notice. The grounds upon which an appeal may be brought are set out at section 174(2)(a)-(g).

Section 289(1) provides for a right of appeal against the Secretary of State’s decision on an appeal against an enforcement notice “on a point of law”.

Pursuant to his power under section 59 of the 1990 Act, the Secretary of State made the GPDO 2015. It provides for the granting of planning permission for certain classes of development. Those classes are set out in Schedule 2.

Part 1 of Schedule 2 is concerned with development within the curtilage of a dwellinghouse. “Dwellinghouse” is not defined by the GPDO, other than at Article 2(1) of the GPDO so as to exclude from its scope “a building containing one or more flats, or a flat contained within such a building.” A “flat” is then defined to mean “a separate and self-contained set of premises constructed or adapted for use for the purpose of a dwelling and forming part of a building from some other part of which it is divided horizontally.”

Class A of Part 1 permits “the enlargement, improvement or other alteration of a dwellinghouse”, subject to exclusions, conditions and limitations which then follow in paragraphs A.1 to A.4.

Small single storey extensions to a dwellinghouse are permitted, provided that they extend beyond the rear wall of the original dwellinghouse by no more than 3 metres (or 4 metres in the case of a detached dwellinghouse), and do not exceed 4 metres in height: see paragraph A.1(f)

Paragraph A.1(g) provides that larger single storey extensions to a dwellinghouse may also be permitted, where they extend beyond the rear wall of the original dwellinghouse by no more than 6 metres (or 8 metres in the case of a detached dwellinghouse), and do not exceed 4 metres in height. However, in the case of these larger extensions, the grant of permission is made subject to a system of prior notification and approval, pursuant to the conditions set out in paragraph A.4. In broad summary, those conditions require that:

Part 3 of Schedule 2 of the GPDO 2015 is concerned with Changes of Use. Class L of Part 3 permits development “consisting of a change of use of a building from a use falling within Class C3 (dwellinghouses) of the Schedule to the Use Classes Order, to a use falling within Class C4 (houses in multiple occupation) of that Schedule” and vice versa.

The Use Classes Order was made in exercise of the Secretary of State’s powers under the predecessor provision to what is now section 55(2)(f) of the 1990 Act, and has been amended since.

In its current form, it defines Classes C3 and C4 as follows:

The current definition of Class C3 was introduced with effect from 6 April 2010, by way of the Town and Country Planning (Use Classes) (Amendment) (England) Order 2010. Class C4 was newly introduced at the same time, and with effect from the same date. Simultaneously, a new class of permitted development was introduced by way of amendment to the GPDO 2015’s predecessor, the Town and Country Planning Act (General Permitted Development) Order 1995 (SI 1995/418) (“the GPDO 1995”). Class I of the GPDO 1995 granted permission for development consisting of a change of use of a building to a use falling within Class C3 from a use falling within Class C4. It was only with effect from 1 October 2010 that the GPDO 1995 was further amended to permit development consisting of a change to a use falling with Class C4 from a use falling within C3.

The Use Classes Order does not provide any definition of “dwellinghouse”. As to the definitions of “single household” and “house in multiple occupation” in the Housing Act 2004 to which Use Classes C3 and C4 respectively refer:

I was referred by both counsel to a guidance note dated 15 January 2014 produced by the Planning Inspectorate to provide advice to its Inspectors entitled “Houses in Multiple Occupation (HMOs) and Permitted Development Rights)”. Both accepted that it did not amount to an authoritative source of law. It reads as follows:

On 1 February 2015, the then owner of the Premises notified LBB of an intention to build a rear single-storey extension pursuant to Class A.1(ea) of Part 1 of Schedule 2 the GPDO 1995. In relevant part, this was in materially identical terms to Class A.1(g) under the GPDO 2015. A determination was sought as to whether prior approval was required for the proposed extension.

As required by paragraph A.4 of the GPDO 1995 (again, in materially identical terms to that of the GPDO 2015 in relevant part), the notification provided the relevant dimensions of the extension: it would extend 6 metres beyond the rear wall of the original dwelling, would be 3m tall at its maximum height, and 3m tall at the eaves. This was within the tolerances permitted by Class A.1(ea) of the GPDO 1995 (and subsequently Class A.1(g) of the GPDO 2015). As also required, it was accompanied by plans indicating the site and showing the proposed development. The required dimensions were marked on the plan’s illustrations of the development. The plans also indicated the internal layout of the extension: it would be composed of a single dining/family room with bifold doors to the garden on the northern elevation.

No adjoining owner or occupier objected to the extension being built. On 17 March 2015, LBB therefore resolved in writing that prior approval was not required for the proposed extension. As all parties accept, that must have been because it accepted that the property was at that time a dwellinghouse enjoying the claimed permitted development rights under Class A.1(ea) of the GPDO 1995, and the proposal met the relevant criteria. The advent of the GPDO 2015, which came into force on 15 April 2015, did not affect the validity of the prior notification for the purposes of permitted development under the new but materially identical Class A.1(g).

In February 2016, a property investment company of which Mr Rothchild is a director purchased the freehold title to the Property. He set about building an extension. He also completed works to render the Property suitable for use as an HMO, by installing bathrooms to form en-suite rooms, and a communal kitchen.

On 22 May 2019, LBB served a Planning Contravention Notice (“PCN”) on Mr Rothchild. The notice alleged that there had been a breach of planning control, namely “Without planning permission, the change of use of the premises into 6 flats and the erection of a single storey extension.” In his response to the PCN dated 13 June 2019:

On 11 December 2019, LBB issued an enforcement notice. The enforcement notice identified the alleged breach of planning control as follows:

“Without planning permission, the material change of use of the premises to a House in Multiple Occupation (HMO) and flats (‘the unauthorised change of use’)

AND

Without planning permission, the erection of a single storey rear extension to the premises (‘the unauthorised development’)”

The enforcement notice required, among other things, the cessation of the alleged unauthorised use and the demolition of the rear extension within 6 months.

On 19 January 2020, Mr Rothchild appealed against the enforcement notice under section 174 of the 1990 Act on grounds (a), (b), (c), (f) and (g).

The appeal proceeded by way of written representations. LBB produced a written Statement of Case, together with various exhibits, in support of its case. In its Statement of Case, LBB contended that the appeal premises were a single planning unit in mixed use as flats and shared HMO accommodation. It contended that at least two of the six units of accommodation within the house met the Gravesham test of containing the facilities required for day to day private domestic existence as such. The remainder of the premises were used as an HMO within the meaning of section 254 of the Housing Act 2004. The extension and other alterations to the property were carried out to facilitate its conversion to flats and a HMO. There was no permitted development right for a change of use from its former use as a single family dwellinghouse to its current mixed use. Nor was there any permitted development right for operational development associated with such use.

In response to the ground (c) appeal (i.e. that the matters stated in the notice did not constitute a breach of planning control), LBB argued that there could not be any permitted change of use to the alleged mixed use. In respect of the extension it said as follows at paragraphs 4.13-4.14:

“4.13

There is no evidence that the appeal premises were a dwellinghouse, for the purposes of the GPDO, at the time of the extension. Whilst the government has advised its Inspectors that some HMOs may benefit from permitted development, status as a dwellinghouse is a matter of fact and degree. The use the appeal premises has been put and the purpose for which the extension was built is a multiple household, communal facility HMO rather than a single household dwelling offering all the facilities for private day to day domestic existence as described in Gravesham.

4.14

The extension was built for the sole purpose of facilitating the unlawful use. It was not built as an extension to a dwellinghouse or to be used as a dwellinghouse within the meaning of the GPDO. It is not permitted development.”

Mr Rothchild’s written representations were submitted late, and so those representations and any evidence he had in support of his case were not provided to the Inspector, and were not taken into account. Although Mr Rothchild was permitted to respond to LBB’s Statement of Case by way of some “Final Comments”, it appears that inadvertently these were not placed before the Inspector either. The appeal therefore proceeded on the basis of LBB’s written case and evidence alone.

On 9 June 2021, the Inspector conducted a site visit. It is said by LBB that on this site visit, he would or should have seen that the rear extension was not (as of that date) laid out as a single dining/family room with bifold doors on the northern elevation, as shown on the original plans attached to the notification. Instead, as at 9 June 2021, it had been split into the narrow communal kitchen on one side with a single door opening to the north into the garden, and a bedroom and ensuite bathroom on the other side with a single window. But no complaint was made about this in LBB’s statement of case; nor even was there a description of the current state of the extension or any allegation as to whether or not it had been constructed in this way at the outset, in May 2016. Although LBB’s witness in these proceedings, Nigel Wicks (who is a planning consultant specialising in enforcement of planning control) has produced a plan showing that this was the layout of the extension as at 14 May 2020, neither this plan nor any other to similar effect was put in evidence before the Inspector.

On 24 August 2021, the Inspector allowed Mr Rothchild’s appeal and quashed the enforcement notice. In summary:

The Inspector’s decision to allow the appeal on ground (b) in respect of the alleged change of use is not the subject of the present appeal: LBB’s appeal before this court is restricted only to the Inspector’s decision to allow the appeal in respect of the extension. It is nonetheless necessary to set out the core of his reasoning in the Decision Letter (“DL”) with respect to the alleged change of use. Since these conclusions are not challenged, I can do so briefly. In summary:

Implicit in that reasoning was the finding that the Property as a whole did provide the facilities required for day-to-day private domestic existence, taking into account the presence of the communal kitchen. Further, it is clear that the Inspector was satisfied that its occupiers were in fact occupying their house as their only or main residence or were to be treated as so occupying it: that is a necessary condition of the definition under section 254(2)(c) of the definition of “HMO”. LBB had not made any suggestion to the contrary: indeed, it was a central part of its own case that the house was being occupied in part as such an HMO, and in part as flats (whose occupiers were on the Council’s case using the accommodation in the same way, but with the benefit of microwave ovens in their room).

The Inspector made no express finding as to how many people were living in the six rooms. However, he made a clear finding that on the date the notice was issued, the appeal property was an HMO falling within Use Class C4, which, as he also expressly set out at DL12, encompassed the “use of a dwellinghouse by not more than six residents as an HMO.”

Before me there was no challenge to the Inspector’s finding that there had been a change of use from Use Class C3 (at the time of the prior approval notification) to Use Class C4 (at some time following Mr Rothchild’s acquisition of the Property), and the appeal proceeded on that basis.

Given his conclusion in respect of the change of use, the Inspector considered only the construction of the extension under the ground (c) challenge. His reasoning on that issue appears at DL20-DL22 which I set out in full below.

“20.

The appellant’s case in this respect, albeit stated very briefly on the appeal form, is that Prior Approval was granted for the extension. That is not strictly correct. In fact, on 17 March 2015 the Council resolved that Prior Approval was not required for a single-storey rear extension to the appeal property extending 6m beyond the rear wall of the original house, with a maximum height of 3m (Council Ref:15/0601). The corollary is that the Council must have accepted that the property was a dwellinghouse at the time.

21.

An HMO is a dwellinghouse. As such, an HMO is capable of benefitting from the provisions of permitted development for the purposes of Class A, Part 1, Schedule 2, Article 3 of the Town and Country Planning (General Permitted Development) (England) Order 2015 (GPDO). The Council does not contend that the extension constructed is not that found not to require Prior Approval in March 2015, or otherwise not permitted development for the purposes of the GPDO. It is academic whether the property was extended whilst still occupied as a single-family dwelling or when already an HMO: it would still constitute permitted development for the purposes of the GPDO. Consequently, I conclude that, on the balance of probability, the erection of the single-storey extension subject to the notice does not constitute a breach of planning control.

22.

Accordingly, the appeal on ground (c) succeeds.”

On 21 September 2021, LBB filed an Appellant’s Notice, and applied for permission to appeal against the Inspector’s decision. There was said to be a single ground of appeal, expressed as follows: “The Inspector misdirected himself in law, when assessing whether the single storey extension to the Property had been built in accordance with the requirements of [the GPDO 2015].”

Although there was said to be only a single ground of appeal, the Appellant’s Notice (which was not drafted by Dr Bowes) in fact made a series of complaints, not all of which are easy to disentangle from each other, and some of which amounted to arguments with the Inspector’s factual findings rather than identifiable errors of law. However, the following three discrete grounds are discernible:

On 10 November 2021, the Government Legal Department wrote to the Court on behalf of the Secretary of State to make clear that he would not defend the appeal, stating that “the Secretary of State accepts that the Inspector erred in failing to consider the use of the property at the time of the extension and whether the rear extension was that granted prior approval in 2015 and that the Decision was consequently unlawful.” This concession reflected grounds (i) and (ii) above, but not (iii).

The third ground was not pursued before me by Dr Bowes. He accepted that the Inspector had found that there had been a change of use from use as a dwellinghouse within Use Class C3 to “Use of a dwellinghouse by not more than six residents as a house in multiple occupation” within Use Class C4, and did not seek to challenge that finding. Instead, Dr Bowes directed his submissions exclusively towards grounds (i) and (ii).

Dr Bowes was right not to pursue ground (iii).

Dr Bowes submitted on behalf of LBB that the Inspector had failed to make any finding as whether the building was in use as a dwellinghouse at the point of the construction of the extension in 2016. Had the building not been in that use at that point, it could not have benefited from the deemed grant of planning permission under the GPDO. The Inspector’s conclusion at DL21 that the building must have been either in C3 or C4 use at the time of the construction of the extension was insufficient: not all buildings which fall within C4 use are dwellinghouses for the purposes of the permitted development rights in the GPDO, even if they afford the facilities required for day-to-day private domestic existence per Gravesham. The Inspector had been wrong to say “An HMO is a dwellinghouse.” It was established in Moore v Secretary of State for Communities and Local Government [2012] EWCA Civ 1202 (“Moore 2012”) at [35]-[36] that there is a further evaluation to be performed, namely whether the “particular characteristics of the use” reveal it to be occupied in a manner “akin to occupation by a single household”. The Inspector failed to make this evaluation.

It did not follow that everything in C4 is to be regarded as being in use as a dwellinghouse, he submitted. That was clear from comparing the different descriptions of C3 and C4 within the Use Classes Order. C3 provided that it embraces “use as a dwellinghouse …”, whereas C4 covers “use of a dwelling house by not more than six residents as a ‘house of multiple occupation’”. To fall within C4, therefore, a building must have the characteristics of a dwellinghouse but it need not be in use as a dwellinghouse.” This view was consistent with that of the Planning Inspectorate in its guidance note, which emphasises at paragraph 3 that the test for whether a property is eligible to use the permitted development right is whether it can be considered a dwellinghouse within the context of the GPDO, and that “this will depend on the facts of the case”.

LBB had raised this point expressly in its Statement of Case in the proceedings before the Inspector at paragraph 4.13, Dr Bowes submitted. The Inspector was therefore wrong to have said at DL21 that “The Councildoes not contend that the extension constructed is not that found not to require Prior Approval in March 2015, or otherwise not permitted development for the purposes of the GPDO.” But even if the point had not been raised, the decision could still not stand, given that a finding that the use of the building was a dwellinghouse when the extension was completed was an essential pre-requisite to lawfully concluding that the extension was not a breach of planning control.

For Mr Rothchild, Mr Mackenzie submitted that Moore 2012 was not authority for the proposition that the GPDO only grants permitted development rights for an extension to a dwellinghouse which is occupied by, or in a manner akin to, a single household, as opposed to any dwellinghouse. Any such argument was inconsistent with Rectory Homes Ltd v Secretary of State for Communities and Local Government [2020] EWHC 2098 (Admin), in which Holgate J expressly accepted that a dwellinghouse may be used in a number of different ways, not just for use by a single household or in a manner akin to such. The GPDO rights permitting an extension to be built apply to any building properly characterised as a dwellinghouse, regardless of the precise use to which that dwellinghouse is put. Any building accepted to fall within Use Class C4 must by definition be a dwellinghouse, and must attract GPDO rights as such accordingly. GPDO rights were not confined to those dwellinghouses which are in use as a single household within Use Class C3. It follows that the Inspector made no error in failing to embark on a determination as to whether, in May 2016, the residents could be said to have occupied the Property in a manner akin to a single household. It was sufficient to find that its use fell within either Use Class C3 or C4 at that time.

On the face of it, Dr Bowes’ submission is flatly inconsistent with the language of Use Class C4 itself. Use Class C4 applies only to the use of a dwellinghouse by not more than six residents as an HMO. If the building in question is not a dwellinghouse at all, it will not fall within Use Class C4 in the first place. Equally, if a building is accepted to be in Use Class C4, it must by definition be a dwellinghouse.

Dr Bowes submits that it nonetheless necessary to consider whether such a dwellinghouse in C4 use is occupied by or in a manner akin to a single household before it can be said to be a dwellinghouse for the purposes of the GPDO. That is again a surprising submission: in R (Innovia Cellophane Limited) v Infrastructure Planning Commission [2012] PTSR 1132, Cranston J emphasised that “dwellinghouse” is well understood in the context of the 1990 Act and secondary legislation made under it, and that like other terms used in the package of planning legislation on the statute book (subject to any express definition to the contrary), should be construed in pari materia. This would recognise the reality that the drafter of a later statute [or in the present case, statutory instrument], obviously related to an earlier one, will have employed a word or concept in the sense that has become accepted in the interpretation of the earlier.

It follows that I would not readily accept that the term “dwellinghouse” had been used in a different sense in Use Class C4 to that in which it had been used in the GPDO, unless there were express words to that effect or authority compelling such a conclusion. Barring the exclusion of flats and any building containing flats from the definition of “dwellinghouse” in the GPDO, there is none.

Dr Bowes’ reliance on Moore 2012 is in my judgment misplaced. His submissions conflate two separate issues that have arisen in the authorities. It is important to disentangle them, in order to explain why the Inspector was not required to ask himself whether the HMO was being occupied “in a manner akin to a single household”, as Dr Bowes suggests.

The first issue concerns whether a building is a “dwellinghouse” for the purposes of planning law. The principles to be derived from Gravesham on that question are well known, and have been reaffirmed many times in subsequent caselaw. I summarise the relevant principles as follows:

The third of those principles should not be understood as requiring a dwellinghouse to be used in any single way. It merely indicates that the nature of the use to which a building is put is one of the factors that may be taken into account in making the required factual assessment as to whether or not it is a dwellinghouse. Thus:

The second issue concerns the question of whether there has been a material change of use of a dwellinghouse. That will obviously be so where the change of use has meant that the building is no longer a dwellinghouse at all, but is used as a hotel, a hostel or a school, for example. But there may still be a material change of use of a building which does not in itself affect its status as a dwellinghouse. This may include a case where the use no longer falls within the same Use Class as it formerly did (or in any Use Class at all); equally, however, the mere fact that a new use falls outside the previous Use Class does not mean that the change of use is a material one. Whether there has been a material change of use of a dwellinghouse is a matter of fact and degree.

In Blackpool Borough Council v Secretary of State for the Environment (1980) 40 P&CR 104, the issue was whether an Inspector hearing an enforcement appeal had erred in law in deciding that an alleged material change of use from a “private dwellinghouse” to “holiday lettings on a commercial basis” had not occurred: he had concluded that if the house was occupied by one household at a time, whether or not on holiday and whether or not paying rent (as some but not all families did), the use was in accordance with the permitted use as a “private” dwelling-house. (The case pre-dated the introduction of Use Class C3, so the issue did not turn in any way upon whether each use fell within that class; but the description of the permitted use as being that of a “private” dwellinghouse is broadly equivalent to it.) Ackner LJ held (at 111) that the Inspector had made no error of law: the Inspector had been entitled to make a finding of fact that the character of the user from a planning point of view had not been changed by the fact that the premises were being occupied not only by the owner and his family but also by his friends or by members of his office staff or by paying tenants during the summer season, and hence that there was no material change of use.

This conclusion did not entail any finding that a dwellinghouse must be occupied by one family or household if it is to retain its status as a “dwellinghouse” (for the purposes of the GPDO or otherwise) as a matter of law: the Court was merely considering whether the Inspector had reached a factual finding to which he was entitled to come, concerning the nature of the use to which the dwellinghouse was being put, and whether it materially differed from its permitted use.

I now turn to Moore 2012 (an unrelated case to Moore 1999), upon which Dr Bowes strongly relies. In that case, the Court of Appeal upheld an Inspector’s decision to dismiss an appeal against an enforcement notice alleging a change of use without planning permission of a house “from a C3 dwelling to use as commercial leisure accommodation which does not fall within Class C3(a)-(c), and which therefore constitutes a sui generis use.” (By this stage, the current version of Use Class C3 was in force.) An eight bedroom dwellinghouse formerly occupied by a family – and which therefore fell within Use Class C3(a) – was now being used for short term holiday lets, managed through a company. The Inspector held that there was no dispute that the property should be described as a “dwellinghouse”, applying the Gravesham test, as it ordinarily afforded the facilities required for day-to-day existence. However, the dwellinghouse was now being used for accommodating up to 20 people at a time for short periods of 3, 4 of 7 nights. The short lets did not, he accepted, disqualify it from being a dwellinghouse. However, on the evidence (as the Inspector noted at his paragraph 15, cited by the Court of Appeal at [12]), it was not clear that the dwellinghouse was only being occupied by single households: there had been a yoga group of 15 people, for example, and a cycling group of 20 people. It appeared that there were many who had come for other reasons, including for reunions, parties and celebrations of various sorts. Such groups were not “single households”. The Inspector had ultimately concluded, after further analysis of the differences between the current use of the property and its use by a family/household, as follows (see [13] of the Court of Appeal’s judgment):

“21.

In summary, I consider there are a number of distinct differences between the current use and use of the appeal property as a family dwellinghouse. Notably, the pattern of arrivals and departures, with associated traffic movements; the unlikelihood of occupation by family or household groups; the numbers of people constituting the visiting groups on many occasions; the likely frequency of party type activities, and the potential lack of consideration for neighbours.

…

25.

Overall, as a matter of fact and degree, I consider the use of the property as part of the appellant’s holiday letting business results in a use of the dwellinghouse that is quite different in character from that of a private family dwellinghouse. I consider this change in character has resulted in a material change of use of the property that is development requiring planning permission under the provisions of Section 55(1) of the Act. No planning permission has been obtained, nor is this any form of permitted development. There has therefore been a breach of planning control, and the appeal on ground (c) must fail.”

The proper characterisation of that conclusion is not that he found the property was no longer a dwellinghouse. It was instead a two stage finding – first that as a matter of fact, the dwellinghouse was no longer being used for a purpose falling within Use Class C3, and second that as a matter of fact and degree, the use to which the dwellinghouse was in fact being put was a material change of use from the permitted Class C3 use.

On appeal before the Court of Appeal, the Appellant did not challenge the finding that the holiday lets business fell outside Use Class C3. However, he argued that the Inspector had erred in law in concluding that the change from such use to use for holiday lets was a material change of use, relying on Moore 1999. The Court of Appeal rejected that submission. Sullivan LJ, giving the judgment of the Court said this at [27]-[29]:

Having considered Moore 1999, Sullivan LJ concluded at [33] that that case was not authority for the extreme proposition that the use of a dwellinghouse for commercial holiday lettings can never amount to a material change of use. He recorded that the Appellant [in Moore 2012] had not contended otherwise, but had nonetheless argued that on the strength of Moore 1999, the Inspector should have approached the question of whether there had been a material change of use on the basis that a dwellinghouse could lawfully be used for some degree of holiday letting without there being a material change of use, and then asked whether there was anything about the particular characteristics of the holiday lettings which amounted to such a change.

Sullivan LJ dealt with that point at [34], concluding that on analysis of the Inspector’s reasoning, that had in fact been the Inspector’s approach (which indeed had been correct). The Inspector had not rejected the Appellant’s argument that a permitted use as a dwellinghouse did not preclude its use for purposes other than as a family dwellinghouse. Instead, he had reminded himself that he had to compare the character of the current use with that of the previous lawful use, and he had then proceeded to examine in some detail the particular characteristics of the current use.

Sullivan LJ then continued at [35]-[36] to examine the Inspector’s reasoning and conclusions. As will be clear, those paragraphs turn on the particular facts of that case, and the Inspector’s approach to it. However, since they form the lynchpin of Dr Bowes’ case, I set them out here.

In my judgment, Sullivan LJ was here doing no more than deciding that the Inspector had reached two unimpeachable conclusions to the effect that:

Contrary to Dr Bowes’ submission, Sullivan LJ was not stating at [35] that the Gravesham test of a “dwellinghouse” must be supplemented by consideration of whether the property in question is occupied by a family or a pre-formed group whose occupation is akin to that of a single household. That suggestion misunderstands the exercise that Sullivan LJ was in fact conducting at this point in his judgment. Indeed, it had been no part of the Inspector’s reasoning that the premises had ceased to be a dwellinghouse.

Similarly, when Sullivan LJ referred at [36] to the finding that there had been a material change of use from “the permitted use as a dwellinghouse”, he was referring to the change of use from the permitted C3 use as a single family/household dwelling, from which the Inspector had found there to have been a material change. He was not suggesting that the Inspector had found that the property was no longer a “dwellinghouse” within the meaning of that term in planning law.

To the contrary, as I have explained above, a “dwellinghouse” may remain as such while being put to a number of different uses. Use Category C3 is not exhaustive of the uses to which a dwellinghouse may be put, as Holgate J made clear in Rectory Homes when rejecting a submission to the contrary at [54]-[57]:

“54.

The Claimant’s argument depends upon an assertion that anything which is a dwelling or dwelling-house must fall within the C3 Use Class. In other words, that Use Class exhaustively defines what may be considered to be a “dwelling” and therefore a unit of residential accommodation falling within Class C2 cannot include a “dwelling”.

55.

The Claimant rightly accepted before the Inspector that a property cannot fall within the C3 Use Class unless it has the physical characteristics of a “dwelling” as defined in Gravesham and is used in a manner falling within that Class (see [30] above). It follows that a property might properly be described as a “dwelling” in accordance with the physical criteria given in Gravesham without being used within the parameters of Class C3. Indeed, Class C3 demonstrates this point, both in the form in which it was originally enacted and in the version substituted (in England, but not Wales) by the Town and Country Planning (Use Classes) (Amendment) (England) Order 2010 (SI 2010 No. 653).

56.

In its original form Class C3 applied to use as a dwelling house either (a) by a single person or “by people living together as a family” or (b) by not more than 6 residents living together as a single household (including where care is provided for residents). Where a single household (not being a family) comprised more than 6 persons, the use would fall outside Class C3, but the property could still be described as a dwelling-house.

57.

The amended version of the C3 Use Class excludes from that Class the use of a dwelling house by no more than 6 residents living together as a single household where no care is provided and the use falls within Class C4 (also introduced in 2010). Class C4 applies to the use of a dwelling house by no more than 6 residents as a “house in multiple occupation” (as defined). Class C4 shows that Class C3 does not cover all cases in which a property has the physical characteristics of, and is used as, a dwelling house. “Dwelling house” is not a term of art confined to the Class C3 Use Class. If recourse is had to the Use Classes Order …, the Order demonstrates that properties having the physical characteristics of a “dwelling” may be used as a dwelling in more than one way.”

Dr Bowes made clear that he was not advancing the same submission as was rejected in Rectory Homes: he did not contend that anything which is dwellinghouse must fall within the C3 Use Class. He accepted that a dwellinghouse could be used as an HMO, and if used as such by not more than six residents, would be in C4 use. However, his further gloss that the HMO must be occupied in a manner akin to a single household if it is to remain a “dwellinghouse” – a proposition which I find difficult to reconcile with the very concept of an HMO as defined in section 254 of the Housing Act 2004 – incorrectly seeks to import a requirement which belongs only in Use Class C3, and cannot properly be derived from Moore 2012.

I further reject Dr Bowes’ argument that it is material in this regard that Use Class C3 embraces “use as a dwellinghouse …”, whereas C4 covers “use of a dwellinghouse”. For a building to fall within either use class, it must both be a dwellinghouse and be used in one of the ways specified in each. Use of a dwellinghouse by people who are to be regarded as forming a single household, or who are living together as such, falls within Use Class C3. But that requirement cannot be imported into either Use Class C4 or into the definition of “dwellinghouse” itself.

My conclusion is also consistent with the Planning Inspectorate’s guidance note, set out at paragraph 22 above. It accurately records that an HMO may have the benefit of the permitted development rights attaching to dwellinghouses, if it is itself a dwellinghouse. Its terms reflect the fact that some HMOs as defined by section 254 of the Housing Act 2004 are not “dwellinghouses” as defined in the GPDO – such as those which are self-contained flats, or which are “converted buildings” which contain a flat. The guidance also reflects the fact that an HMO may be a dwellinghouse even if is not in C4 use (as C4 use requires no more than 6 residents to using the dwellinghouse). It confirms that the Gravesham test must be applied to any HMO to determine whether it is in fact a dwellinghouse. But the guidance note provides no support for the view that a “dwellinghouse” must be occupied in a manner akin to a single household before it can be considered to be such for the purposes of the GPDO, nor for the view that a dwellinghouse in use as an HMO within Use Class C4 is not a necessarily a dwellinghouse for the purposes of the GPDO.

Finally, as the Senior President of Tribunals observed in City & Country Bramshill Limited v SSHCLG [2021] 1 WLR 5761, at [28], the decision letter must be read fairly, with due tolerance for minor imperfections or infelicity. There are two such infelicities in DL21, but neither affects the lawfulness of the Inspector’s decision.

The Inspector made no error of law in concluding that, whether the Property fell within Use Class C3 or C4 at the time of construction of the extension, the HMO enjoyed permitted development rights as a “dwellinghouse” under the GPDO. He therefore made no error of law in concluding that it was academic whether the Property was extended whilst it was still occupied as a single-family dwelling or when already an HMO, following its permitted change of use under Class L of the GPDO. Ground (i) accordingly fails.

Under this ground of appeal, LBB contends that even if the Property was in use as a dwellinghouse at the time that the extension was built, the extension was not built in accordance with the information supplied in the prior approval notification. LBB point to the fact that at the time of the site visit, it would have been apparent to the Inspector that the extension was not laid out as a single dining/family room with bifold doors in the northern elevation, but had been sub-divided into the communal kitchen and a bedroom with ensuite bathroom, with a door and window in the northern elevation.

As Dr Bowes frankly acknowledged, this point formed no part of LBB’s case on appeal at all. There was no evidence before the Inspector describing the current layout of the extension; still less was there any evidence describing the layout at the time the extension was built. Nor was he invited to ascertain what the original layout had been on his site visit. The Inspector’s express observation at DL21 that “The Council does not contend that the extension constructed is not that found not to require Prior Approval in March 2015” is entirely accurate.

Dr Bowes submits that there is no general rule that a party to a planning appeal is prevented from raising, in a challenge to that decision, an argument that had not been advanced in representations made on the appeal, and referred me to Newsmith Stainless Ltd v Secretary of State for the Environment, Transport and the Regions [2001] EWHC Admin 74; [2017] PTSR 1126. In that case, Sullivan J (as he then was) observed at [12] - [15] as follows (underlining added):

“12.

Mr Craig drew my attention to the decision of Mr George Barlett QC, sitting as a deputy judge of the Queen’s Bench Division, in South Oxfordshire District Council v Secretary of State for the Environment, Transport and the Regions [2000] All ER 667. The Encyclopedia in para 288.16 summarises the effect of his decision in this way:

“there was no general rule that a party to a planning appeal was to be prevented from raising, in a challenge to that decision, an argument that had not been advanced in representations made on the appeal. If the inspector had omitted a material consideration, the decision could be unlawful, notwithstanding that the matter had not been raised in representations.”

13.

It is important that the South Oxfordshire decision is not regarded as a licence to introduce new material, that is to say material that was not before the inspector, in section 288 applications. That this was not the deputy judge’s intention is plain from the manner in which he dealt with the two additional grounds of challenge that were in contention in that case. …

15.

Whilst I accept that there is no general rule preventing a party from raising new material in a section 288 application, it will only be in very rare cases that it would be appropriate for the court to exercise its discretion to allow such material to be argued.It would not usually be appropriate if the new argument would require some further findings of fact and/or planning judgment (matters which are for the inspector not the court).”

I accept Mr Mackenzie’s submission that I should not exercise my discretion to allow this new point to be introduced at this stage. Had the Inspector considered the point he would have had to:

LBB never raised any of these matters. Mr Rothchild did not, therefore, have the opportunity to respond to them in his “Final Comments” in response to LBB’s case. (It is irrelevant that those Final Comments were not put before the Inspector in any event: that was an error on the part of the Inspectorate.) It would have been procedurally unfair for the Inspector to deal with the issue without seeking such representations: compare Commercial Land Ltd v Secretary of State for the Environment, Transport and the Regions [2002] EWHC 1264 (Admin) at [40]-[41].

It might well be that the Inspector had the jurisdiction to raise these matters with the parties, had he adverted to the point and considered it necessary to make a determination upon it. But that falls a long way short of establishing that he had an obligation in law to do so: see Taylor & Sons v Secretary of State for the Environment, Transport and the Regions [2001] EWCA Civ 1254 at [40]-[42]. As explained at [40], even if a potential point becomes apparent to an Inspector on a site visit which was not apparent from the written representations, it is well within his or her discretion not to lengthen the process by reverting to the parties for further comment and submissions. Further, as observed by the Court at [42], “The function of a site visit is to enable an inspector to make a judgment about submissions which have been made rather than to explore new possibilities. If the latter were to become commonplace it would be a fruitful breeding ground for further disputes.”

Similarly, in West v First Secretary of State [2005] EWHC 729 (Admin), Richards J (as he then was) explained at [42] that “the general rule is that it is incumbent on the parties to a planning appeal to place before the inspector the material on which they rely. Where the written representations procedure is used, that means that they must produce such material as part of their written representations. The inspector is entitled to reach his decision on the basis of the material put before him.” Although the Inspector does have an inquisitorial burden in reaching his decision on the basis of the parties' written representations, as Richards J explained at [44], in general “that process does not require anything beyond proper consideration of the material put forward by the parties.”

In my judgment, the Inspector was entitled to record that LBB did not contend that the extension constructed was not that which had been found not to require prior approval in March 2015, and he was not bound to raise the matter further simply because his site visit in June 2021 showed a different internal layout and fenestration from that shown in the notified plans. He committed no error of law in proceeding on that basis. Nor is this a case where he can be said to have committed an “error of fact” in the sense which gives rise to an error of law, as described in E v Secretary of State for the Home Department [2004] EWCA Civ 49 at [63]: LBB’s claim that the extension was not built in accordance with the notified plans is not a matter of established fact, and LBB cannot be said not to be responsible for the Inspector’s failure to consider the point.

In the circumstances, ground (ii) fails also.

The appeal is dismissed. I am conscious that the Secretary of State was prepared to concede that the Inspector erred in law in respect of both grounds (i) and (ii). However, for the reasons I have given I am satisfied that he did not do so.

I am grateful to both counsel for their very full and well informed written and oral submissions. At my invitation at the close of the hearing, both counsel also submitted further written submissions on the issue of whether, if I acceded to the Appellant’s submissions, I should nevertheless not remit the decision. In the event, it is not necessary for me to address those submissions.