Scoring the Hazards Three sets of figures are used to generate a hazard score; these are:

- A weighting for each Class of Harm reflecting the degree of incapacity to the victim resulting from the occurrence;

- The likelihood of an occurrence involving a member of a vulnerable age group, expressed as a ratio; and

- The spread of possible harms resulting from an occurrence, expressed by percentage for each of the four Classes of Harm.

**How does HHSRS work ?**The first of these, the weighting given to each Class of Harms, remains fixed and is shown in Table 1 below. This built-in fixed weighting means that, given the same likelihood, those hazards that cannot result in death (e.g. risks from poor ergonomics) will not produce a Score as high as those which may cause death (e.g. risks from carbon monoxide).

__Table 1__

__Weightings for the Classes of Harm__Class of Harm / Weighting

I. Extreme / 10,000

ii. Severe / 1,000

iii. Serious / 300

iv. Moderate / 10

The other two sets of figures represent the informed professional judgments made by the surveyor of the likelihood and of the potential spread of harms.

The Hazard Score is calculated as the sum of the products of the weightings for each Class of Harm which could result from the particular hazard, multiplied by the likelihood of an occurrence, and multiplied by the set of percentages showing the spread of Harms.

__The HHSRS Formula__

Class of Harm Weighting

Likelihood Spread of Harm (%) Result i. 10,000 X 1/L X 01 = S1 ii. 1,000 X 1/L X 02 = S2 iii. 300 X 1/L X 03 = S3 iv. 10 X 1/L X 04 = S4 Hazard Score = S1+S2+S3+S4

__Judging the Likelihood__The surveyor judges the likelihood of an occurrence over the next twelve months which could result in harm to a member of a vulnerable age group. For the HHSRS, the judgemental is limited to the likelihood of an occurrence resulting in outcomes which would or should require some medical attention – a visit to a doctor or hospital. This is because the rating system deals only with those hazards which could cause significant harm outcomes (and so carry a significant Class of Harm weighting). It is only these outcomes for which there is recorded data to inform the judgemental

The judgemental of the likelihood made by the surveyor involves taking account of the conditions (deficiencies) identified during the survey, in particular whether those conditions will increases or reduce the average likelihood of an occurrence.

Thus, the surveyor should assess the likelihood having regard to:

- The average likelihood given for the particular type and age of dwelling;

- The dwelling characteristics and conditions identified during the survey, which are the responsibility of the landlord, and which:

ii Those which may reduce the likelihood of such an occurrence.

*Example –**For falls*on

*stairs*, the surveyor determines the likelihood of a fall occurring over the following twelve months which could result in a Class l to lV Harm to a member of the vulnerable age group. This involves taking account of such matters as the going, the presence or absence of handrails, the state of repair of the treads, variations in tread or riser dimensions, and the available lighting.

For

*dampness*and

*mould growth*etc, the surveyor determines the likelihood of the dampness causing Class I to IV Harm to a member of the vulnerable age group over the next twelve month period, taking into account the extent and degree of the dampness and its location in the dwelling.

To inform the surveyor’s judgment, national average likelihood's of an occurrence involving a person in the vulnerable age group are given in the Hazard Profiles. Where data is available, these are given for different age groups and dwellings. These averages represent the likelihood for the typical condition that could be expected in a dwelling of that particular age and type.

Assessing likelihood is not determining or predicting that there definitely

__will__be an occurrence. Even where it is judged that there is a very high likelihood, such as a 1 in 10 probability, it is accepting that the likelihood of no occurrence is nine times greater than that of an occurrence.

The surveyor is not expected to give a exact likelihood ratio, but to select one of the standard HHSRS likelihood ranges – e.g., the range of 1 in 24 to 1 in 42; or the range of 1 in 420 to 1 in 750. For each of the standard ranges a representative scale point is used in the Hazard Rating Formula to calculate the Hazard Score. See Box 3 for the standard HHSRS ranges of likelihood's, and the Representative Scale Points of those ranges that is used in the Hazard Rating Formula.

__HHSRS Standard Range of Likelihood's__Some hazards may be present in several locations. The surveyor judges the likelihood range for the dwelling as a whole. Fall on the level will include reviewing the condition of all the floors and the paths and yards associated with the dwelling. Damp and mould will involve reviewing the severity of dampness and mould in all the rooms within the dwelling.

The surveyor assesses the collective likelihood of an occurrence at the dwelling as a whole and this should take account of all the factors associated with each location. For a bed sit on the first floor of a three storey building falls on the stairs includes the whole staircase from the second floor through the first floor and ground floor to the external steps to the front door and any garden steps to front or rear.

The surveyor assesses the collective likelihood of an occurrence at the dwelling as a whole and this should take account of all the factors associated with each location. For a bed sit on the first floor of a three storey building falls on the stairs includes the whole staircase from the second floor through the first floor and ground floor to the external steps to the front door and any garden steps to front or rear.