The Housing Health and Safety Rating System (England) Regulations 2005

Seriousness of hazards

6.—(1) Where, following an inspection of residential premises under section 4 of the Act, the inspector—

(a) determines that a hazard of a prescribed description exists; and

(b) considers, having regard to any guidance for the time being given under section 9 of the Act in relation to the assessment of hazards, that it is appropriate to calculate the seriousness of that hazard,

the seriousness of that hazard shall be calculated in accordance with paragraphs (2) to (4) of this regulation.

(2) The inspector shall assess the likelihood, during the period of 12 months beginning with the date of the assessment, of a relevant occupier suffering any harm as a result of that hazard as falling within one of the range of ratios of likelihood set out in column 1 of Table 1.

Table 1

Column 1	Column 2
Range of ratios of likelihood	Representative scale point of range
Less likely than 1 in 4200	5600
1 in 4200 to 1 in 2400	3200
1 in 2400 to 1 in 1300	1800
1 in 1300 to 1 in 750	1000
1 in 750 to 1 in 420	560
1 in 420 to 1 in 240	320
1 in 240 to 1 in 130	180
1 in 130 to 1 in 75	100
1 in 75 to 1 in 42	56
1 in 42 to 1 in 24	32
1 in 24 to 1 in 13	18
1 in 13 to 1 in 7.5	10
1 in 7.5 to 1 in 4	6
1 in 4 to 1 in 2.5	3
1 in 2.5 to 1 in 1.5	2
More likely than 1 in 1.5	1

(3) The inspector shall assess which of the four classes of harm (set out in Schedule 2) a relevant occupier is most likely to suffer during the period mentioned in paragraph (2).

(4) The inspector shall—

(a) assess the possibility of each of the other classes of harm occurring as a result of that hazard, as falling within one of the range of percentages of possibility set out in column 1 of Table 2;

(b) record each possibility so assessed as the corresponding RSPRR set out in column 2 of Table 2; and

(c) record the possibility (which shall be known, for the purposes of the formula in paragraph (5), as the RSPPR) of the most likely class of harm occurring as a percentage calculated using the following formula—

Where—

• A is the RSPPR recorded under sub paragraph (b) as the second most likely class of harm;

• B is the RSPPR recorded under sub paragraph (b) as the third most likely class of harm; and

• C is the RSPPR recorded under sub paragraph (b) as the fourth most likely class of harm.

Table 2

Column 1	Column 2
Range of percentages of possibility	Representative scale point of the percentage range (RSPPR)
Below 0.05%	0%
0.05 to 0.15%	0.1%
0.15% to 0.3%	0.2%
0.3% to 0.7%	0.5%
0.7% to 1.5%	1%
1.5% to 3%	2.2%
3% to 7%	4.6%
7% to 15%	10%
15% to 26%	21.5%
26% to 38 %	31.6%
Above 38%	46.4%

(5) When the inspector has assessed likelihood under paragraph (2) and assessed the possibility of each harm occurring under paragraph (3), the seriousness of that hazard shall be expressed by a numerical score calculated using the following formula—

Where—

• 
  
  
  

(6) For the purposes of the formula in paragraph (5)—

(a) L is the representative scale point of range in column 2 of Table 1 corresponding to the range that has been recorded under paragraph (2);

(b) O1 is the RSPPR recorded under paragraph (4) in relation to Class I harm;

(c) O2 is the RSPPR recorded under paragraph (4) in relation to Class II harm;

(d) O3 is the RSPPR recorded under paragraph (4) in relation to Class III harm;

(e) O4 is the RSPPR recorded under paragraph (4) in relation to Class IV harm.

(7) In this regulation—

“relevant occupier” means, where the risk of harm concerned is associated with the occurrence of any of the matters or circumstances listed in—

(a)

paragraph 1 of Schedule 1, an occupier under the age of 15 years;

(b)

paragraph 2, 3 or 6(a) of Schedule 1, an occupier aged 65 years or over;

(c)

paragraph 7 of Schedule 1, an occupier under the age of 3 years;

(d)

paragraph 8 of Schedule 1, an occupier aged 60 years or over who has been exposed to radon since birth;

(e)

paragraph 11 of Schedule 1, the actual occupier;

(f)

paragraph 17, 22, 23 or 25 of Schedule 1, an occupier under the age of 5 years;

(g)

paragraph 19, 20, 21, 24 or 28 of Schedule 1, an occupier aged 60 years or over;

(h)

paragraph 26—

(i)

except where a collision is with low architectural features, an occupier under the age of 5 years, and

(ii)

where a collision is with low architectural features, an occupier aged 16 years or over;

(i)

any other paragraph of Schedule 1, any occupier; and

“RSPPR” means the representative scale point of the percentage range.

(8) In making assessments under this regulation, an inspector shall have regard to any guidance for the time being given under section 9 of the Act.