Investview Limited v Tandridge District Council

Introduction

1. This is an appeal from a decision by the First-tier Tribunal to uphold 15 Prohibition Orders in respect of properties of which the appellant, Investview Limited, is the freehold owner; the orders were imposed by the respondent local housing authority, the Tandridge District Council, in response to what it regarded as a number of hazards including inadequate space.

2. The appellant was represented by Mr Josef Cannon KC and Mr Riccardo Calzavara, and the respondent by Ms Poonam Pattni-Evans, and we are grateful to them all.

3. There are two issues in the appeal; one is whether in considering whether a “crowding and space” hazard existed the FTT disregarded relevant space standards, and the other is whether the FTT erred in accepting the respondent’s calculation under the Housing Health and Safety Rating System (“HHSRS”). The legal background

4. This appeal is about the size of the accommodation provided at the appellant’s property, and the risk that that might pose for its occupants. A number of different legal regimes are, or may be, relevant to the size of residential accommodation. Town and Country Planning

5. Obviously planning permission is required when accommodation is built. The Nationally Described Space Standards (the “NDSS”) set out the requirements for the gross internal floor area of new dwellings, which differ depending on the number of occupants, bedrooms and storeys in the dwelling, A single-storey one-bedroom dwelling for one person is required to have a GIA of 39 m 2 , or 37 m 2 if there is a shower room rather than a bathroom.

6. Planning permission is also required for a change of use. The Town and Country Planning (General Permitted Development) (England) (Order) 2015 enables certain changes of use to proceed without the need for a full application for planning permission. In particular, a change from office use to residential falls under the GPDO regime; the effect of the 2015 Order is to grant planning permission for that change of use provided that an application is made to the local planning authority for a decision as to whether prior approval is required. The authority has 56 days in which to respond, failing which there is deemed consent.

7. Before 6 April 2021, in responding to such an application the local housing authority was not able to consider the size of the accommodation proposed. However, the 2015 Order was amended with effect from 6 April 2021 by the addition of paragraph 3(9A) (where paragraph 3 provides that the planning permission is granted for the developments described within Schedule 2): “(9A) Schedule 2 does not grant permission for, or authorise any development of, any new dwellinghouse— (a) where the gross internal floor area is less than 37 square metres in size; or (b) that does not comply with the nationally described space standard issued by the Department for Communities and Local Government on 27th March 2015.” “Dwellinghouse” in the relevant part of Schedule 2 to the 2015 Order includes a flat. Statutory overcrowding

8. Part X of the Housing Act 1985 defines overcrowding by reference to room sizes and the number of people sleeping in a room; a room where one person sleeps is overcrowded if it is less than 70 ft 2 /6.5 m 2 . It is in some circumstances a criminal offence to allow a house or flat to be overcrowded as defined in the 1985 Act .

9. Just pausing there, it will be seen that there is a big gap between the minimum size for a new dwelling for one person (or a converted dwelling, after 6 April 2021) and the minimum size required to comply with the size requirements in Part X of the 1985 Act . A house or flat that is not statutorily overcrowded may nevertheless be much smaller than it would have to be to get planning permission today. The Housing Health and Safety Rating System

10. Part 1 of the Housing Act 2004 is concerned with the responsibility of local housing authorities for health and safety in properties. It introduced a system of classification of hazards; it requires the authority to take enforcement action when Category 1 hazards are found to be present in a property, and enables it to do so when Category 2 (less serious) hazards are present.

11. The Housing Health and Safety Rating System (England) Regulations 2005 set out a system for the assessment of the seriousness of hazards, by a procedure known as an HHSRS assessment, whereby hazards are given a numerical score by reference both to the level of harm they could cause and to the likelihood of that harm occurring. Regulation 7 sets out “prescribed bands” based on the hazard’s overall score; band A is a hazard that scores 5,000 or more, a band D hazard scores 500 to 999, band H scores 20 to 49. Hazards within bands A to C are category 1, bands D and below are category 2.

12. The 2004 Act provides for a range of enforcement actions, for example an improvement notice requiring specified action to be taken within a specified time (section 11 and following), or a prohibition order preventing the use of a building or part of it (section 20 and following). A prohibition order must specify the hazard to which it relates and the deficiencies giving rise to the hazard (section 22); it may be suspended pending specified events. Failure to comply with a prohibition order, without a reasonable excuse, is an offence (section 2). A person on whom a prohibition notice is served can appeal against it to the FTT (paragraph 7 of Schedule 2 to the 2004 Act ). The appeal is a re-hearing and the FTT must make its own decision, but should give special weight to the local authority’s views ( Hussain v Waltham Forest LBC [2023] EWCA Civ 733 ). The Decent Homes Standard

13. The Decent Homes Standard sets minimum criteria for social housing in the UK. Among other things it includes a requirement that the housing be free of Category 1 hazards. The regulation of houses in multiple occupation

14. The Housing Act 2004 defines houses in multiple occupation (“HMOs”) and requires some, but not all of them, to be licensed. Schedule 4 of the 2004 Act requires certain conditions to be included in all HMO licences. One of those conditions is at paragraph 1A(2)(a): “(a) to ensure that the floor area of any room in the HMO used as sleeping accommodation by one person aged over 10 years is not less than 6.51 square metres”.

15. The origin of that requirement in the statutory overcrowding regime is obvious. Furthermore, in considering an application for an HMO licence the local housing authority has to consider whether it meets prescribed standards for occupation by the number of households or persons specified in the licence; the prescribed standards referred to are to be found in Schedule 3 of the Licensing and Management of Houses in Multiple Occupation and Other Houses (Miscellaneous Provisions) (England) Regulations 2006. They include minimum sizes for bedrooms, depending upon the number of occupiers (6.51 m 2 for a bedroom occupied by one person over 10 years of age), but not for other rooms.

16. Room sizes derived from the thresholds for statutory overcrowding are obviously very small; many local authorities have provided additional guidance for their housing officers, and it is well-established that it is acceptable for them to do so: Clark v Manchester City Council [2025] UKUT 389 (LC) .

17. HMOs differ widely. A building that has been converted into self-contained flats is not an HMO unless it was not built in compliance with the building regulations in force at the time of its construction ( section 257 of the Housing Act 2004 ). The factual background

18. Survey House, Whyteleaf, Surrey, used to be a three-storey office with a shop front. In 2019 the appellant sought prior approval from the respondent (as local planning authority) for a change of use from commercial to residential, pursuant to the Town and Country Planning (General Permitted Development) (England) (Order) 2015 (see paragraph 6 above); the respondent did not respond, and so the change of use had planning permission.

19. The building was then converted into 15 self-contained flats. It is not in dispute that the flats were built in compliance with the building regulation regime; the building is therefore not an HMO (see paragraph 17 above). The largest of the flats has an internal area of 22.5 m 2 , the smallest 16 m 2 , and most are either 17.5 or 20 m 2 . Each comprises a single room for sleeping, living and cooking, and a little toilet and shower room.

20. The appellant’s plan was to offer the flats as accommodation for the homeless, and to that end Croydon Council carried out an inspection under the “Decent Homes” criteria and some remedial work was carried out. In November 2020 the respondent granted a five-year lease of the building to Oliver Landon Limited, for the purpose of providing accommodation to occupants “provided by the Local Authority for use as temporary accommodation in the private housing sector” and to others, and it was so used.

21. In January 2024 officers of the respondent including Ms Dickman, a Private Sector Housing Officer, inspected the property. Ms Dickman carried out a HHSRS assessment and as a result prohibition orders were issued in respect of all 15 flats. The orders were suspended for three months, and were later suspended again pending the FTT proceedings. The hazards specified in the orders were all described as Category 2 hazards. In each of the orders “Crowding and space” was listed as a hazard, as was “Position and operability of amenities”, in all but one “Flames and hot surfaces” was listed, and in a couple “lighting” was also listed. The prohibitions orders required that “The premises shall not be used for human habitation”. Each of the orders also specified the remedial action that the authority said would result in the revocation of the order; so far as crowding and space were concerned, the remedial action was said to be: “Reconfigure the property to provide a usable floor space of 26.5 m2 for living, cooking and sleeping (exclusive of the shower room).”

22. The appellant appealed to the FTT against the prohibition orders. The decision of the FTT

23. At the hearing the appellant’s case was that the flats did not provide insufficient space, and that the other hazards identified were less significant and could be remedied, so that the orders should be revoked. Before the FTT the appellant called as an expert witness Mr Rozner, of Regalway Property Licensing, a specialist in residential property licensing. Ms Dickman gave evidence for the local housing authority. Mr Rozner’s opinion was that there was no crowding and space hazard at Survey House, while Ms Dickman’s evidence explained her assessment following her inspection.

24. So far as space was concerned, the FTT focused first on the parties’ arguments about the applicable statutory regime. It was clear that Survey House was not an HMO; but Mr Rozner suggested that local HMO standards were relevant as an analogy, and explained that the “Essex Standards” recommend 11 m 2 for a fully self-contained unit, while the respondent itself set a higher requirement of 14 m 2 . The appellant also relied to some extent on the fact that it had planning permission, that the conversion complied with building regulations, and that it had passed the Decent Homes inspection.

25. The respondent argued that the NDSS was relevant, even though none of the flats met this standard and even though the respondent’s requirement for remedial action was that the appellant should provide an area (26.5 m 2 ) that would fall below the requirement in the NDSS. It was pointed out, for the respondent, that the NDSS was, by the time of the hearing, part of the GPDO regime (see paragraph 6 above).

26. Ms Dickman’s opinion was that the units in Survey House “do not provide a sufficient space to adequately separate different household activities, to store personal possessions, or to safely arrange basic items of furniture associated with normal household life.” Her calculation of the level of risk posed by the lack of space in the flats put the hazard in Band D, and that was the reason why prohibition notices were served. We say more about her calculation below.

27. The FTT accepted the respondent’s arguments and evidence. It gave no weight to the fact that the units had planning permission and were compliant with building regulations (and there is, unsurprisingly, no appeal in relation to that). As to the Decent Homes inspection it said: “62. …The Appellants again relied upon this assessment of which there is no evidence to suggest it was not properly conducted. The Tribunal has heard that government policy changed around this time 30 September 2020, and that new domestic units would need to meet the Nationally Prescribed Space Stand, (NPSS). The Tribunal finds that the impact of this statement is that the 15 flats are brought into the assessment regime of HHSRS referencing Standards (NPSS) superseding the Decent Homes Inspection.” (Emphasis is the FTT’s own)

28. As to local HMO standards, the FTT said that it was agreed that the building was not an HMO and went on to say: “63. …As a consequence, the applicability of guidance to HMOs, which are occupations that differ from self-contained flats are not considered to be of relevance in determining the question of overcrowding under the HHSRS regime. The Tribunal therefore does not give weight to the assessments carried out on the space standards derived from HMOs.”

29. As to the NDSS the FTT referred to an earlier FTT decision where the relevance of the NDSS to converted rather than new properties had been discussed and concluded: “64. … Given the ministerial statements from 2020 when the NDSS was formally adopted as a minimum space standard in the GPDO, the Tribunal finds that these are equally applicable to new properties.”

30. It also looked at the Metric Handbook, which is a guide for builders and architects, and pointed out that the units in Survey House were “significantly and materially” lower than the sizes given in the Metric Handbook and the NDSS.

31. Finally the FTT considered Ms Dickman’s calculation of level of the hazard posed by the size of the unit, and accepted it. The FTT upheld the prohibition orders on the basis of the “crowding and space” hazard, and therefore made no findings on the other hazards identified. The appeal

32. The appellant appeals with permission from the FTT on two grounds. The first is that the FTT was wrong to give no weight to HMO size standards but should instead have regarded them as relevant by analogy. The second is that the FTT was wrong to accept the respondent’s calculation of the seriousness of the hazard under the HHSRS. The FTT acknowledged in granting permission that it had not explained why it preferred Ms Dickman's evidence to Mr Rozner's.. We consider the grounds in turn. The relevant size standards The arguments

33. The appellant’s argument is simple: although neither Survey House nor any of the units within it is an HMO, the size standards applicable to HMOs are relevant considerations. As Mr Cannon KC pointed out, if the conversion of Survey House had not been compliant with building regulations it would have been an HMO, and the units would have been of adequate size in accordance with the respondent’s own guidelines (which indicated that 14 m 2 was adequate for a self-contained unit) as well as with the Essex standards.

34. For the respondent, Ms Pattni-Evans pointed out that the Essex standards were not shown to the FTT. There was a copy in the appeal bundle, dated December 2022; it indicates that the standards it sets out are inapplicable to self-contained units which include all the basic amenities including kitchen and shower; such units should comply with the NDSS. Ms Pattni-Evans argued that the FTT was therefore right to disregard them because they assume that the occupant also has some shared space (as is typical of HMOs). She pointed out that the respondent was not requiring compliance with the NDSS, but regarded it as relevant and important in this context. Decision about the relevant standards

35. The FTT’s paragraphs 62, 63 and 64 exhibit some confusion. It is not the case that the Decent Homes standards have been superseded by the NDSS (as the FTT’s paragraph 62 appears to indicate, assuming that that is what is meant by “NPSS”). The Decent Homes standard is relevant to social landlords and is concerned only with Category 1 hazards. So the FTT was right to have no regard to the fact that the building passed the Decent Homes inspection, even though the detail of what it said at its paragraph 62 was not correct.

36. If the FTT’s paragraph 64 was intended to say that the NDSS is now applicable to converted properties, for the purposes of planning permission, then that is correct; but that was not the case when deemed planning permission was obtained for Survey House. The NDSS is relevant, but by analogy only, and it is important to note that the respondent is not requiring compliance with the NDSS.

37. As to the FTT’s paragraph 63 and local HMO standards, whether or not they are applicable to self-contained units, it is difficult to see why they are irrelevant. There is no standard directly applicable to the units in Survey House, save for the statutory overcrowding rules – and the units are well above that standard. The FTT would therefore have found it useful to consider, purely by analogy, a range of standards. It was of course relevant that the units fall short of the requirements of the NDSS; but equally relevant was the fact that they exceed at least some local HMO standards.

38. Nevertheless the appeal cannot succeed on this ground. The appellant’s expert witness did not provide copies of the Essex or any other local standards to the FTT. In principle local HMO standards were relevant, but the FTT was not shown enough information to be able to take them into consideration. Its decision cannot be faulted on this basis. Ground 2: the HHSRS score The evidence before the FTT and the arguments in the appeal

39. Here we have to look at Ms Dickman’s calculation of the seriousness of the crowding and space hazard under the HHSRS. As we said above, the score is calculated on the basis of the likelihood of occurrence of harm as a result of the hazard, and the level of harm. The Housing Health and Safety Rating System Operating Guidance , published by the Office of the Deputy Prime Minister in February 2006, explains the scoring system.

40. Mr Rozner took the view that there was no crowding and space hazard at Survey House, and so did not provide an HHSRS calculation in respect of that hazard. Ms Dickman’s calculation, was as follows.

41. First she looked at the likelihood of occurrence of harm. “Harm” is defined in the Operating Guidance (paragraph 3.10) as an occurrence that would or should require medical attention, such as a visit to the doctor or to hospital. The Operating Guidance indicates (at paragraph 11.04) that the national average likelihood of such harm occurring in a post-1979 flat as a result of a crowding and space hazard is 1 in 8,000 – albeit that the Guidance also acknowledges the difficulty in quantifying the effect of crowding and states that its figures have “a relatively weak evidence base” (paragraph 11.03). In her calculation Ms Dickman noted that average and assessed the likelihood in each unit as 1 in 180.

42. When asked, in cross-examination, to justify that figure Ms Dickman said it was her professional judgment.

43. Ms Dickman then assessed the likely levels of harm. The Operating Guidance classifies levels of harm in classes I-IV, where Class I harm is “Death from any cause”, Class II covers “severe harm”, of which examples include serious burns, loss of consciousness for days, and the like, Class III includes chronic severe stress, malignant but treatable skin cancer and sleep disturbance, while Class IV covers moderate harm such as slight concussion. Those classes and descriptions are relevant to any type of hazard. The Operating Guidance sets out the national average spread of health outcomes specifically for crowding and space (paragraph 11.04), ascribing for example 14% to Class I, which means (if correct) that where a crowding and space hazard is present, 1 in 8,000 people living in the unit will suffer harm as a result (i.e. harm requiring medical attention), and 14% of those people will suffer class I harm (i.e. will die).

44. The likelihood of each type of harm is then given a weighting, resulting in the following calculation by Ms Dickman: Class Weighting Likelihood Spread of harm Scores I 10,000 1/180 14% 778 II 1,000 1/180 7% 39 III 300 1/180 26% 43 IV 10 1/180 53% 3 Total = 863

45. A score of 863 is in Band D, and at that level a Prohibition Order is regarded by the respondent as appropriate.

46. For three of the flats Ms Dickman assessments showed the likelihood of harm as 1/100, which yielded a final score of 1553, which took the hazard to Band C; in cross-examination in the FTT however she said that the likelihood for all the flats should be 1/180.

47. The FTT did not analyse Ms Dickman’s calculation. It accepted it as her professional judgment, in the absence of any competing figure from Mr Rozner – who of course did not carry out a calculation because he thought there was no crowding and space hazard.

48. The appellant’s argument is that the figures for the likelihood of harm - 1/180 - was random and unrealistic. Ms Dickman was unable to explain it. If she had assessed the likelihood at 1/800, for example, the resulting overall score would have been below the level at which a Prohibition Order would have been imposed. She was also unable to explain her assessment that there was a 14% chance of class 1 harm being suffered by the 1 in 180 people who would suffer harm; it was put to her in cross-examination that that figure was “not real” and her response was “I just took it from the guidance”.

49. Moreover, the FTT did not explain why it rejected Mr Rozner’s evidence that there was no crowding and space hazard in the units.

50. The respondent’s case in the appeal was that Ms Dickman’s calculation was the best evidence before the FTT. There was no challenge to her qualifications or experience, and in assessing the likelihood of harm environmental health officers are using their experience of multiple properties, and it was reasonable for the FTT to accept her professional judgment. Decision on Ground 2.

51. It will be apparent from the table above that by far the largest component of the ultimate score of 863 was the supposed likelihood of Class I harm, which was heavily weighted. The weightings are imposed by the Operating Guidance and are not susceptible to individual judgment; the crucial judgments are therefore (a) the likelihood of 1/180 and (b) the likely spread of classes of harm which Ms Dickman took as being the same as the national average.

52. Neither judgment was explained by Ms Dickman, and it was clear from her evidence in cross-examination that her assessment of the spread of harm was taken from the guidance rather than being something she had thought about. Professional judgment is of course acquired and honed by experience; it is not a gut feeling. A judgment is a rational outcome from the consideration of the material on which the expert, experienced professional is able to draw, and he or she must be able to explain that consideration and show why it led to a particular conclusion. Ms Dickman’s inability to justify her figure of 1/180, , or to say for example why she thought the figure was not, say, 1/800 (10 times as likely as the national average) or 1/2000 (four times as likely) means that her figure appears to be an instinct, at best, rather than a judgment. She could not point to any experience that led her to conclude that her assessment was appropriate. As to her judgment about the spread of harm, she did not appear to have thought through practical implications of her calculation, which implies that – albeit in a very small number of cases – the lack of space in each unit was life-threatening.

53. The FTT is required to reach its own decision rather than reviewing the respondent’s decision. We fail to see how it could have relied on Ms Dickman’s calculation.

54. Equally, the FTT’s rejection of Mr Rozner’s evidence that the size of the units was not a hazard, meaning that it was not going to cause harm of a kind that needed medical attention, was unexplained. That is not to say it was inexplicable; the photographs in the bundle indicate that these units are very small indeed, and in some of them the shower is under the eaves so that an adult could not stand up in it. It is not difficult to imagine for example mental health problems being at least exacerbated in such conditions. Nevertheless an explanation of the rejection of Mr Rozner’s evidence was called for.

55. The FTT’s acceptance of Ms Dickman’s calculation appears to be irrational, as well as unexplained; its rejection of Mr Rozner’s evidence that there was no crowding and space hazard is unexplained. Those were serious errors and the FTT’s decision to uphold the prohibition orders has to be set aside. Conclusion

56. The FTT’s decision is set aside. It is not possible for the Tribunal to substitute its own judgment, and the matter is remitted to the FTT to be decided afresh by a different panel. It is likely that in making a fresh decision the FTT will need to consider the hazards other than crowding and space, so that the parties have a decision on all aspects of the prohibition orders. Judge Elizabeth Cooke Mr Mark Higgin FRICS FIRRV 11 December 2025 Right of appeal Any party has a right of appeal to the Court of Appeal on any point of law arising from this decision. The right of appeal may be exercised only with permission. An application for permission to appeal to the Court of Appeal must be sent or delivered to the Tribunal so that it is received within 1 month after the date on which this decision is sent to the parties (unless an application for costs is made within 14 days of the decision being sent to the parties, in which case an application for permission to appeal must be made within 1 month of the date on which the Tribunal’s decision on costs is sent to the parties). An application for permission to appeal must identify the decision of the Tribunal to which it relates, identify the alleged error or errors of law in the decision, and state the result the party making the application is seeking. If the Tribunal refuses permission to appeal a further application may then be made to the Court of Appeal for permission.