Controversy continues over the existing statutory standard of fitness for human habitation and the proposed housing hazard rating system. Norman Parkinson and Robyn Fairman present their analysis and opinions in the second of two features on risk and environmental health

The Housing Hazard Rating System is, apparently, standing in the wings awaiting parliamentary time for its introduction. Let us hope that there is still time to stop it.

It is hard to see who has been driving its development, for there is a groundswell of opposition at grassroots level. Professional bodies and some local authorities have supported proposals for a rating system but until very recently there has been little detail about how it has been derived, how it might operate and how it might be integrated into the legislative framework.(1) A lack of published detail has been characteristic of the review process.

The Statutory Standard of Fitness
Before considering the proposed system, it would be useful to consider the current standard. The statutory standard of fitness has existed, more or less in its current form, for almost 50 years. It parallels common law notions that dwellings should be "reasonably suitable for occupation", but the Housing Act limits the matters that may be considered in deciding whether a dwelling is statutorily fit to those contained in a list in section 604.

In practice, acting upon a complaint, request for advice, application for grant aid or as part of some proactive policy, local authority officers carry out a systematic room-by-room, elevation-by-elevation inspection, noting the nature and extent of "defects". The officer must first decide whether relevant defects cause the dwelling-house to fail one or more of the requirements in the statutory list, and, secondly, the officer must decide whether or not by reason of that failure the dwelling-house is not reasonably suitable for occupation. A qualitative risk assessment forms part of this judgement. In coming to a decision, the officer uses professional judgement based upon education, training and experience and must have regard to the Secretary of State's guidance in the Department of the Environment (DoE) circular 17/96. The officer must have a clear understanding of the judicial precedents which govern the legal interpretation of the phrase "not reasonably suitable for occupation" and be aware that while the courts are not bound by the circular, they are bound by judicial precedent.

Although, there may be some differences of opinion and judgement, as there will be in any professional matter and in relation to any type of measure or standard, the DoE research found that there was a high level of agreement over decisions.(4)

It is important to recognise that professional qualitative judgements are not "low level" approximations of quantitative assessments. They are inclusive, holistic and often highly complex and analytical. Quantitative assessments, by their very nature, are limited, exclusive and restrictive.

Objective view
The list in the Standard of Fitness has been criticised for the omission of several important factors,4 including several identified by the Building Research Establishment (BRE) as serious health and safety hazards.(2,3) There is also the requirement that each of the factors in the statutory list must be considered in isolation, which does not allow a cumulative overall assessment of whether the dwelling is reasonably suitable for occupation. The statutory guidance can be criticised for being often unhelpful in practice, patronising in tone and in conflict with some of the judicial precedents. Relatively minor changes to the legislation and a new circular could have overcome these problems, but the Department of Transport, the Environment and the Regions (DETR) appears to have opted for major reform, rather than minor changes.

There has been a long standing goal of making the standard more "objective". Presumably, its reliance on professional judgement is seen as a weakness. As the DoE has stated, the eradication of personal judgement in the assessment of housing conditions is unattainable.(4)

Other criticisms are that the standard does not differentiate between degrees of unfitness, and that local authorities are not coping with the numbers of unfit houses. The former is correct but is not a valid criticism since the legislative framework within which the standard is applied does not require such differentiation. If it did, a qualitative risk assessment could easily be introduced as part of a decision-making framework based on professional judgement. As for the latter, the real problem is not with the fitness standard but with political priorities and the allocation of resources.

The Housing Hazard Rating System
This system, sometimes referred to as the Housing Fitness Rating System and the Housing Health and Safety Rating, has been developed by the DETR to replace the Statutory Standard of Fitness. It is intended to be a logical and practical method of quantitatively assessing and grading houses from a health and safety perspective which is evidence-based and capable of being justified in court.

The proposed system is based on hazards only, whereas the current standard is much broader and takes into account not only health and safety, but also comfort, convenience, efficiency and privacy - factors which may be very important to an occupier.

Under the proposals, a systematic inspection would be carried out in much the same way as at present, but, instead of a professional qualitative assessment of whether the premises are reasonably suitable for occupation, a quantitative assessment of hazards will be made. The process would employ hand-held computers with touch-screen data entry.

From the DETR Consultation Paper (5) and Battersby and Ormandy1, the process would seem to be as follows: stage one will identify "faults"; stage two will determine which faults contribute to "hazards" (faults which affect comfort, convenience, etc, will not be computed); stage three will assess the severity of the hazard, by comparing it with an "ideal"; stage four will assess the likelihood of a hazardous incident occurring over the following 12 months, and stage five will consider the class of health outcome which might result.

This process will identify a "Hazard Profile Rating", derived from likelihood and severity of "harm". Despite claims to the contrary, this is a classic risk assessment process, albeit of the semi-quantitative type.

Hidden agenda?
Inevitably, despite the DETR's intention to make the standard more "objective", professional and technical judgement will be needed in the identification of the faults, identification of hazards, assessment of severity of hazard, estimation of likelihood of harm, and class of health outcome. Officers will have to select numbers from a range on the computer screen. All of these judgements and numbers may need to be explained and justified in court.

The rating threshold between fit and unfit will, apparently, be set by central government - not the "proper officer", not the local housing authority, and not the courts. It may be that this reveals the hidden agenda. This threshold will, obviously, dictate the number of unfit dwellings and thereby influence "need" and the allocation of resources.

The interpretation of the results of the quantitative assessment appears to be based on work by the Health and Safety Executive (HSE) on perceptions of "acceptable", "tolerable" and "unacceptable" annual risk of death.

Criticisms
The case for major reform, rather than simple correction of the deficiencies of the current standard, has not been articulated and debated. It seems that the review process has achieved such a momentum that costly change is inevitable, whether it is needed or not.

Yet the current approach is well understood, is straightforward and sits easily in the legislative framework. Fitness judgements are relatively easy to explain and justify to the public and the courts. There is no great literature criticising the operation of the existing standard. A wealth of experience and precedent has been built up in its interpretation. All that is needed is minor change and some decent guidance.

The adoption of a new system would place a great burden on already stretched local authorities in retraining their staff, introducing new systems and purchasing and maintaining the necessary computers and software. Inevitably, it will take years for the new system to be debugged and for uniformity and consistency in its operation to be achieved.

Although both the existing and proposed systems deal with health and safety hazards, the proposed system does not adequately address issues which are, nevertheless, very important to the public that we serve: issues such as comfort, efficiency, convenience and privacy. To that extent, the proposal represents a lowering of the standard.

The Hazard Rating Scheme sets out to be an evidence-based method, justifiable in court, using available scientific information, to measure and prioritise the risks presented in housing and to enable dwellings to be identified which may be subject to enforcement action and/or qualify for financial assistance. Yet there is little sound evidence underlying it and it is a recipe for litigation. Lawyers and expert witnesses will make their fortunes as the numbers underlying the quantitative judgements are questioned and debated in the courts.

Despite its name, the Hazard Rating System is a risk assessment because it attempts to ascribe probabilities to possible outcomes and rate the severity of the damage. Last month's article on risk assessment described and analysed the use of such techniques in environmental health regulation and suggested appropriate uses for different types of risk assessment. The hazard rating system appears to be a ranking system with elements of a scoring system.

If the prioritisation of dwellings for inspection is the aim, a simple ranking system based upon pre-defined criteria would suffice. However, an objective of the Hazard Rating System is that it should also identify dwellings for enforcement action. To fulfil that role, an evidence-based quantitative risk assessment would be needed, but it is questionable whether there is enough data to support quantitative risk assessments of the multitude of circumstances and defects typically found in housing fitness inspection. Data would be needed on the nature and extent of defects that cause health effects.

Dose-response relationships would need to be established and consideration given to whether a threshold exists. The assessment would need to consider the response of the target population, and there are likely to be significant differences in human responses. The nature of the harm which is to be considered in these studies would also need to be defined. Harm is a complex and controversial concept. Environment Agency research has identified 22 attributes of harm, including social and economic factors, as well as health outcomes; it has yet to reach a satisfactory conclusion.(6)

Despite this dearth of evidence, in the proposed system quantitative estimates of risk are ascribed to building faults. The system makes comparisons with HSE-derived standards of what is acceptable, tolerable and unacceptable. These are used in the manufacturing industry and are based on experience in the nuclear industry. They relate to experience of what society - industry, workers, unions, the HSE and politicians - has been prepared to tolerate. Derivation of the standards is based upon a process known as "revealed preference" which, as pointed out last month by Robyn Fairman, has been heavily criticised in the literature. In addition, the use of such concepts in the domestic environment is highly questionable.

Acceptable?
Battersby and Ormandy state that it has been established that an annual risk of death of 1 in 10,000 is "acceptable".(1) In fact, acceptable risk is defined as 1 in 1,000,000.(9) If we were to use that figure, it would probably shift most dwellings in the country over the enforcement action threshold! The figure of 1 in 10,000 is the maximum tolerable risk for members of the public from any single non-nuclear plant and 1 in 100,000 is the maximum tolerable risk for members of the public from any new nuclear power station.(9)

"Tolerable" is vastly different from "acceptable". The HSE in their Tolerability of Risk Framework state that even when risks fall in the "tolerable" region, control measures must be introduced to drive risk down to the "acceptable" region, and any residual risk is tolerable only if further risk reduction is impracticable, or requires action that is grossly disproportionate, in terms of time, trouble and effort, to the reduction in risk which is achieved.(10)

The HSE regards the use of tolerability criteria as merely guidelines to be interpreted with common sense and not intended to be used as benchmarks to be complied with in all circumstances.(10) The HSE uses a housing example to make its point. The risk of death from the use of gas is 1 in 1,350, 000, yet, they state "gas incidents give rise to societal concern, particularly where the incidents occur because unscrupulous landlords seek to avoid the cost of a simple safety check, and so put those who rent the accommodation at greater risk. In effect, societal concerns override averaged numerical considerations."(10) The HSE felt that it was necessary to initiate legislation, a national campaign and an active enforcement policy even though the risks involved are far lower than "tolerability" limits, and would, by straightforward application of those limits, be deemed "acceptable".

The Royal Commission on Environmental Pollution (RCEP) shares that view and has stated that "even if it is possible to estimate accurately the statistical probability of a specified event, that probability may not in itself be an appropriate basis for reaching a judgement about the tolerability of human activities that give rise to that probability".(11)

Conclusion
The proposed Housing Hazard Rating System would unnecessarily introduce enormous complexity and uncertainty into a system that has traditionally relied on a simple and straightforward professional judgement. It might, validly, be used in the determination of priorities, inspection frequencies, house condition surveys, etc, but if it is introduced to determine the threshold for statutory intervention at the level of the individual house, it has the potential to become a litigation nightmare. The deficiencies of the present standard of fitness are well documented and generally accepted.

Minor changes to the standard, together with good statutory guidance is all that is needed to overcome these deficiencies. If a differentiation is required between degrees of unfitness, this could be accommodated through a simple professional judgement incorporating a qualitative assessment of risk. We hope that common sense will prevail.

References
1. Battersby, S and Ormandy, D (1999) "Surveying the System for Hazard Rating", EHJ, Vol 107/11, London.
2. Building Research Establishment, (1995a) Building Regulation and Health, BRE, London.
3. Building Research Establishment, (1995b) Building Regulation and Safety, BRE, London.
4. DoE (1993) Monitoring the New Fitness Standard, HMSO, London.
5. DETR (1998) Housing Fitness Standard - Consultation Paper, DETR, London.
6. Duarte-Davidson R, Pollard S, Yearley R, Llewellyn G and Steck J (1999) Considering Environmental Harm - Qualitative, Semi-Quantitative Treatments for Strategic Risk Assessment. Proceedings of 9th Annual Conference of the Society for Risk Analysis, Rotterdam.
7. EHN - various articles and letters to the editor, eg 17/4/98, 1/10/99, 12/11/99, 10/12/99, and personal communications.
8. Fairman, R (2000) "Risk Assessment in Environmental Health Regulation", EHJ, Vol 108/08, London.
9. Health and Safety Executive, (1992) The Tolerability of Risks from Nuclear Power Stations (second edition), HMSO, London.
10. Health and Safety Executive, (1999) Reducing Risks, Protecting People, HSE London.
11.Royal Commission on Environmental Pollution (1998) 21st Report: Setting Environmental Standards, The Stationary Office, London.

This article was submitted before the publication of the DETR Housing Health and Safety Rating System: Guidance (version 1) - July 2000. The authors acknowledge the additional detail and explanation in the guidance document, but retain their opinion of the proposed system.

The views expressed in this article are those of the authors and not those of the CIEH which has supported the continuing development of the Rating System to assess its practicability, given the the inadequacies of the current fitness standard. While the CIEH welcomes the views of members on government publications and developments relevant to the environmental health profession, it also recognises that these may well be disputed by the researchers, on whose work the government publication is based. Consequently, David Ormandy of Warwick University, who carried out most of the work on preparing, developing and testing the proposed system, will be presenting a paper for the next edition of EHJ, in which he will argue that some of the assumptions made here are incorrect.

Informed debate will ensure that any new system will be effective. The Chartered Institute is seeking to ensure that as many people as possible get the first hand opportunity to hear about the Rating System and its potential use. That is why a series of seminars have been arranged where the DETR will provide speakers to explain the basis of the Rating System and its proposed application and use. The seminars will take place at the following venues: The Victoria Thistle Hotel, London, 12 October; the Royal York Hotel, York, 17 October; and the Cardiff Marriott Hotel, 25 October.