Water Consumption Research Project No contact households (Phase 3) - PowerPoint PPT Presentation

Water Consumption Research Project No contact households (Phase 3) August 2014

Background • This phase of WCRP was conducted to analyse the ‘no contact’ households from Phase 1 • No contact means the door was not answered when the market researcher visited • Purpose of this study is to determine if water consumption is different in no contact households

Methodology • Targets the no contact households from Phase 1 – Target sample identified 5,790 households • circa 4 months meter readings • Consumption per day calculated as total metered quantity divided by number of days from date of install to date of meter read.

Methodology • Door to door survey carried out by market research company • On this occasion surveys were conducted later on weekdays and on two Saturdays • Sensitive sites removed from list • Data collected: – Architecture type – Number of bedrooms – Number of occupants per house, including adults and children • Assumption that surveys are answered and recorded honestly and in good faith

Limitations • No data on socio-economic profile or age of respondents • Sample selection limited to households that had meters installed before December 2013 • Mostly suburban areas – reflects installed meters

Assumptions • Households greater than 800 litres/day removed using the same methodology as the initial study • Household usage is most closely correlated with occupancy • Children are defined as children under 18 living in the household. • Sample is not representative of CSO population census but provides a useful snapshot of households metered so far • Annual consumption is extrapolated from available data 1 A total of 23 outliers were removed.

Survey sample (ex outliers) Children 0 1 2 3 4 5 Total 1 31 10 2 1 1 45 2 117 58 78 33 6 3 295 Adults 3 34 9 8 5 56 4 17 3 3 2 25 5 5 1 6 6 1 1 Total 205 80 92 41 6 4 428

Sample geographic distribution 55 54 Latitude 53 52 -12 -10 -8 -6 -4 Longitude

Survey validation Comparison of survey household proportions to CSO census data: CSO WCRP 1 occupant 24% 7% 2 occupants 29% 30% 3 occupants 18% 22% 4 occupants 16% 25% 5 occupants 9% 11% 6 + occupants 4% 5% Apartment 9% 1% Terraced 17% 16% Semi-detached 28% 39% Detached 3 42% 43% 2 Bungalows added to detached households as CSO does not use bungalow as a classification

Survey validation Comparison of survey household size (occupancy) to CSO census data: CSO WCRP Apartment 2.0 1.5 Terraced 2.5 3.1 Semi-detached 2.8 3.3 Detached 3.0 3.2 Total 2.7 3.2

Data distribution (ex outliers) 50 40 30 Frequency 20 10 0 0 100 200 300 400 litres per person per day

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Phase 1 vs Phase 3 Phase 1 No contact (phase 3) Sample size litres/person Sample size litres/person 1 occupant 94 171 31 123 2 occupants 335 140 127 123 3 occupants 353 108 94 100 4 occupants 428 94 105 87 5 occupants 265 83 49 86 6 + occupants 111 84 22 83 Total 1,586 428 Detached 435 110 186 101 Semi-detached 748 106 166 101 Terraced 370 109 70 111

Phase 1 vs Phase 1 & 3 Phase 1 Phase 1 & 3 Sample size litres/person Sample size litres/person 1 occupant 94 171 125 159 2 occupants 335 140 462 135 3 occupants 353 108 447 106 4 occupants 428 94 533 93 5 occupants 265 83 314 83 6 + occupants 111 84 133 84 Total 1,586 2,014 Detached 435 110 621 107 Semi-detached 748 106 914 105 Terraced 370 109 440 110

CSO weighted average • Overall average consumption/person in WCRP study can be weighted to CSO census data • Multiply the WCRP average litres/person for each occupancy by the number of people living in households 3 with the same level of occupancy. • Divide the resulting litres consumed nationally by the population that have a public mains connection 3 Household with public mains connection as per CSO Census 2011

CSO weighted average Phase 3 A - CSO B - CSO National/litres Occupancy Households Occupants C - litres/person (B * C) 1 occupant 302,967 302,967 123 37,176,885 2 occupants 369,976 739,952 123 90,939,780 3 occupants 225,130 675,390 100 67,245,469 4 occupants 198,002 792,008 87 69,005,960 5 occupants 101,926 509,630 86 43,589,257 6 + occupants 49,184 316,125 83 26,183,819 Total 1,247,185 3,336,072 100 334,141,171 • Weighted average: 100 litres per person per day

CSO weighted average Phase 1 & 3 A - CSO B - CSO National/litres Occupancy Households Occupants C - litres/person (B * C) 1 occupant 302,967 302,967 159 48,171,753 2 occupants 369,976 739,952 135 99,893,520 3 occupants 225,130 675,390 106 71,591,340 4 occupants 198,002 792,008 93 73,656,744 5 occupants 101,926 509,630 83 42,299,290 6 + occupants 49,184 316,125 84 26,554,500 Total 1,247,185 3,336,072 109 362,167,147 • Weighted average: 109 litres per person per day

Summary • CSO census weighted phase 3 water consumption per person per day is lower – this needs to be considered in the context of a smaller sample size • When Phase 1 and 3 are added together the CSO weighted average is close to the 111 litres per person per day previously reported • Biggest difference is for one and two occupant households – Possibly due to the occupiers being outside of the home more often, e.g. young professionals • Incremental usage is in line with the proposed child allowance