Housing Health & Safety - Part 2 - How to carry out a Housing Health & Safety Rating System (HHSRS) Assessment

The inspector is required to undertake what is fundamentally a risk assessment of  29 different hazards and quantify this by calculating a score for each hazard.  Therefore a house could actually have 29 different scores.  A common misconception with HHSRS is that a single score is calculated for each dwelling

Source: http://blogs.aldermoorfarm.coventry.sch.uk

In last week’s article I discussed health & safety in the home and in particular the way in which habitation and health & safety issues were assessed under the former fitness standard.  The article identified why the fitness standard was limited in its scope and how this has now been addressed since the introduction of the Housing Health & Safety Rating System (HHSRS) in 2006.  

When an inspection is made under HHSRS, usually by an Environmental Health Officer or a Building Surveyor, the inspection will consider a wide range of potential hazards under 29 different categories, which are divided into four main groups:

Physiological requirements	Psychological requirements	Protection against infection	Protection against accidents
·         Damp and mould growth ·         Excess cold ·         Excess heat ·         Asbestos and manufactured mineral fibre ·         Biocides ·         Carbon monoxide and fuel combustion products ·         Lead ·         Radiation ·         Uncombusted fuel gas ·         Volatile organic compounds	·         Crowding and space ·         Entry by intruders ·         Lighting ·         Noise	·         Domestic hygiene, pests and refuse ·         Food safety ·         Personal hygiene, sanitation and drainage ·         Water supply for domestic purpose	·         Falls associated with baths ·         Falling on level surfaces ·         Falling associated with stairs and steps ·         Falling between levels ·         Electrical hazards ·         Fire ·         Flames and hot surfaces ·         Collision and entrapment ·         Explosions ·         Position and operability of amenities ·         Structural collapse and failing elements

The inspector is required to undertake what is fundamentally a risk assessment of each of the 29 different hazards and quantify this by calculating a score for each hazard.  Therefore a house could actually have 29 different scores (although this is unlikely as hazards would need to be identified for every category for this to happen).  A common misconception with HHSRS is that a single score is calculated for each dwelling, which is completely incorrect. By looking at the scope of the 29 categories it is clear to see how comprehensive the assessment is compared to the fitness standard (see last week's article) and although habitation issues are still included, a HHSRS assessment considers much wider health & safety issues that will impact on those occupying/visiting a dwelling.  

In order to arrive at a score for each hazard the inspector firstly needs to have a good knowledge of the rating system and how it works.  This requires an understanding of what to look for/at under each hazard, an appreciation of how serious an issue may be, which will include an assessment of the likeliness of the hazard occurring and also an understanding of the seriousness of the hazard should it occur.  This demonstrates that an inspection is much more than identifying hazards/issues, it is also about considering the likelihood and impact as well, which is not an exact science.  When HHSRS was first introduced and prior to undertaking the pilot surveys I discussed in my previous article I remember spending a great deal of time reading the guidance produced by the Department of the Deputy Prime Minister (now the Department of Communities and Local Government), which I have to say is very good and well worth a read if you are unfamiliar with HHSRS (Link).

Source:http://www.goodfieldconsulting.co.uk/risk-assessment/

The inspection itself is very different to anything that I had undertaken previously as a Building Surveyor.  To demonstrate how a hazard is assessed and how a score is calculated I will use the example of the potential for someone to fall out of a window.  This could be due to serious disrepair, inappropriate glazing, lack of sufficient guarding, damage or missing restrictors etc. It is important to note that this is something that would not have been considered under the fitness standard. Let us assume that the window in question is within the first floor bedroom of a typical two storey dwelling.  As with all risk assessment processes there needs to be an assessment of likelihood and severity. 

Likelihood - Firstly, the inspector must ask themselves how likely is it that the hazard will occur? This will depend on a number of factors such as the severity of disrepair, location, where in the room the window is located etc. Likelihood is expressed as a ratio and is the subjective opinion of the inspector, based upon the evidence he/she sees at the time of inspection.  So, there will be a greater likelihood of a hazard occurring if a window is in serious disrepair, with damaged glazing which is located in a position that someone could fall onto it, compared with a window with minor disrepair and at a height that it would be more difficult for someone to fall onto it.  This demonstrates two possibilities under the same HHSRS hazard, but each posing a different likelihood of occurring.  In the first instance the inspector may decide on a 1 in 10 likelihood of the hazard being realised and in the second the inspector may decide there is a much lower likelihood and allocate a ratio of 1 in 100.  There is no exact science to this however the assessment allows the hazard to be quantified.

Severity – Next the inspector must ask themselves, if the hazard is realised how serious will the consequences actually be?  HHSRS refers to this as the ‘Spread of Harms’.  A great deal of research was carried out during the development of HHSRS and part of this involved the production of data from accident statistics and input from organisations such as The Royal Society for the Prevention of Accidents (RoSPA). This enabled the significance of hazard outcomes to be defined (HHSRS allocated classes – see below) and subsequently allowed these to be quantified for score calculation purposes. For example, research data showed that for every 100 people who have turned up in hospital Accident and Emergency departments, from information collected, it can be show (for each hazard) that: 

W% will be dead	Class I
X%  will have broken several bones and will be in traction for some months	Class II
Y%  will be patched up and referred to outpatients	Class III
Z%  will be told to go home and take an aspirin	Class IV

To avoid confusion HHSRS also defines each of the classes above to provide consistency during the inspection and assessment process and for the score calculation process. Each of the four classes are weighted to reflect the significance of the potential harm:

HHSRS  - Spread of harms definitions:

Class I – Extreme  Death, permanent paralysis below the neck, malignant lung cancer, regular severe pneumonia, permanent loss of consciousness, and 80% burn injuries.	Weighting 10,000
Class II – Severe Chronic confusion, mild strokes, regular severe fever, loss of a hand or foot, serious fractures, very serious burns and loss of consciousness for days.	Weighting 1,000
Class III -  Serious Chronic severe stress, mild heart attack, regular and persistent dermatitis, malignant but treatable skin cancer, loss of a finger, fractured skull, severe concussion, serious puncture wounds to head or body, severe burns to hands, serious strain or sprain injuries and regular and severe migraine.	Weighting 300
Class IV – Moderate Occasional severe discomfort, chronic or regular skin irritation, benign tumours, occasional mild pneumonia, a broken finger, sprained hip, slight concussion, moderate cuts to face or body, severe bruising to body, 10% burns and regular serious coughs or colds.	Weighting 10

For some situations there may be one likely outcome, but for most there could be a number of possible outcomes, in terms of the level of harm, so the spread of harms could cross all four separate classes. For example, falling out of a window on the 80^th floor of a block of flats would provide only one outcome – death (So class 1 would be 100% and classes II, III & IV would each be 0%), however falling out of a second floor window might give a range of possible outcomes, giving a figure (percentage) across each of the four classes of harm.

Once the inspector has decided on the likelihood and established the spread of harms (available from HHSRS guidance, within each hazard) it is then finally possible to calculate a score.  This is done by dividing the weighting of each harm class by the likelihood and multiplying by the spread of harms.  I know this is confusing so it more easily demonstrated by using our example of someone falling out of a first floor bedroom window, in the first instance let’s assume that the likelihood is low:

Class	Class of harm weightings		Likelihood 1 in		Spread of Harms		Total
I	10,000	÷	500	x	0.2	=	4
II	1,000	÷	500	x	1.6	=	3.2
III	300	÷	500	x	7.9	=	4.74
IV	10	÷	500	x	90.3	=	1.81
Total        13.75 (14)

As you can see the score calculation of 14 is low, but see what happens to the hazard score below if the issue is more serious and the inspector thinks there is a much greater likelihood: 

Class	Class of harm weightings		Likelihood 1 in		Spread of Harms		Total
I	10,000	÷	5	x	0.2	=	400
II	1,000	÷	5	x	1.6	=	320
III	300	÷	5	x	7.9	=	474
IV	10	÷	5	x	90.3	=	180.6
Total     1374.6 (1375)

Nowadays there are spreadsheets as well as various mobile technology applications, with built in spread of harms data for each hazard, which will do these calculations with only minimum input necessary from the inspector.  Having said that I would not let any of my Surveyors undertake these types of assessments without understanding the method explained above first.  This is important to help them understand the significance of each hazard as well as trying to achieve consistency between inspectors.  Remember, the assessment is the opinion of one individual and therefore subjective.

Once scores have been calculated for HHSRS categories’ each hazard into a category 1 or a category 2 hazard:

Band	Hazard Score
A	5000 or higher
B	2000 to 4999
C	1000 to 1999
D	500 to 999
E	200 to 499
F	100 to 199
G	50 to 99
H	20 to 49
I	10 to 19
J	9 or less

Any hazard identified with a score of 1000 or above will fall within band A, B or C (depending on the score), and is classified as a Category 1 hazard.  The existence of a Category 1 hazard will invoke compulsory Enforcement Action by the Local Authority if not dealt with urgently.  Also, category 2 hazards should not be ignored and steps should be taken to eliminate, reduce or manage these hazards as well.

In order to explain the system, discuss the assessment process and cover score calculation, this article is a little longer than my usual articles.  This was necessary in order to cover some of the key points in what at face value can seem to be a complicated system.  Hopefully, I have provided an appreciation of the different mindset that is required by an inspector and demonstrated that these assessments should only be carried out by those who have the right level of knowledge and understanding of the system and how it works.

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