Report 3: Metered fuel consumption

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1 Report 3: Metered fuel consumption Including annex on high energy users Prepared by BRE on behalf of the Department of Energy and Climate Change December 213 BRE report number

2 The EFUS has been undertaken by BRE on behalf of the Department of Energy and Climate Change (DECC). Report editors and lead authors: Jack Hulme, Adele Beaumont and Claire Summers. Project directed by: John Riley and Jack Hulme. Data manager: Mike Kay. Supporting authors and analysts: Mike Kay, Busola Siyanbola, Tad Nowak, Peter Iles, Andrew Gemmell, John Hart, John Henderson, Afi Adjei, Lorna Hamilton, Caroline Buchanan, Helen Garrett, Charlotte Turner, Sharon Monahan, Janet Utley, Sara Coward, Vicky Yan & Matt Custard. Additional thanks to the wider team of reviewers and contributors at BRE, DECC and elsewhere, including GfK NOP Social Research, Gemini Data Loggers, Consumer Futures, G4S, Eon, British Gas, and for the input of the Project Steering Group and Peer Reviewers.

3 Executive Summary This report presents the results from an analysis of the median gas and electricity consumptions derived from the 211 Energy Follow-Up Survey (EFUS). The 211 EFUS consisted of a follow-up interview survey and associated monitoring of a sub-set of households first visited as part of the 21/211 English Housing Survey (EHS). Analysis is based on the meter reading sub-sample weighted to the national level, using a weighting factor specific to the meter reading sub-sample. The results presented in this report are therefore representative of the English housing stock, with a population of 21.9 million households. The meter reading data reveals a wide range in energy consumption across the household stock 1. For gas, annualised consumption values ranged from a minimum of 3 kwh and a maximum of 76,5 kwh. For electricity, annualised consumption values ranged from a minimum of 4 kwh and a maximum of 35,1 kwh. For both fuels, the frequency distributions show considerable tailing towards the higher electricity consumption values, resulting in mean values that are considerably higher than the median values. In order to give a reasonable comparison across categories within typical dwelling and household groups, the report uses the median values throughout. The median annual mains gas consumption determined using the EFUS meter reading data is around 14, kwh, with a median value of around 3,7 kwh for electricity. 8% of households use between 5,9 to 28, kwh of gas per annum and between 1,8 and 8,8 kwh of electricity per annum. Significant differences are found in the average consumption levels for different categories of dwelling and household types. Gas use is closely linked to dwelling floor area as well as household size, with detached houses having a median gas consumption more than twice that found in flats. Electricity use appears to be related to the number of people in the household, with the data showing a median consumption of around 2,4 kwh for single people, compared with a figure of around 6, kwh where there are at least 5 people in the household. Households living in dwellings built between 1919 and 1944 show a significantly higher median gas consumption than those from other periods with a median of 17,1 kwh per year, a pattern that is also seen in the NEED report. These households also have a higher median electricity consumption than households living in dwellings built between 1965 and 198. There is no statistically significant difference in the median gas consumption of households living in rural or urban areas. However, median electricity consumption is significantly higher in households in rural areas compared to urban areas, likely to be due to the large number of dwellings in these locations without a gas supply. 1 These data are annualised to cover the period 15 th November 21 to 14 th November 211. This includes a very cold period in December 21, which acts to raise consumption when compared to calendar year 211 estimates.

4 There are no significant differences in the median consumption of either gas or electricity between households living in dwellings with or without wall insulation, nor between households living in dwellings with differing levels of loft insulation. However, households living in dwellings that are fully double glazed have median gas consumptions that are lower than those households living in dwellings which are not fully double glazed. There is some evidence of lower median gas consumption with increasing levels of different insulation measures, although the only statistically significant difference can be seen between those households living in well insulated dwellings (3 insulation measures) having both lower gas and electricity consumption than households living in poorly insulated dwellings. On average, owner occupiers consume significantly more gas than any other tenure and more electricity than the private rented or local authority tenures. For both fuels, the private rented, local authority and RSL tenures show no significant differences in their median annual consumption rates. gas consumption is lower for households in the lowest income quintile compared to households in all other income quintiles with around 7,5 kwh separating the median gas consumption in the highest and lowest income quintiles. The median electricity consumption increases as the income quintiles increase, however the difference is only statistically significant between the first income quintile and the top three income quintiles. The trend of higher use of both gas and electricity and higher incomes is what might be expected when considering the larger size of dwelling that might typically be associated with high incomes and the ability to afford higher fuel bills and in fact, similar median values are found for all income groups when the consumption is normalised for floor area. There are no significant differences in the median consumption values of either gas or electricity between households in which someone is in during the day and households in which no-one is in during the day. In dwellings where the household is said to be underoccupying, the median gas consumption is significantly higher than where they are not under-occupying. There is no significant difference in the median consumption of either fuel for households in fuel poverty compared to those not in fuel poverty.

5 Table of Contents 1 Introduction Methodology Weighting factors Findings Average consumption values Variation in household consumption patterns by dwelling characteristics Consumption by dwelling type Consumption by dwelling age Consumption by floor area Consumption by region and area type Consumption by energy performance Household consumption patterns Consumption by tenure Consumption by household size Consumption by household type Consumption by age of household reference person (HRP) Consumption by household employment status and income Consumption by occupancy characteristics Conclusions and further analysis Annex A: Focus on High Energy Users Annex A: Executive Summary A1 Introduction and Methodology A2 Findings A2.1 High gas consumers A2.1.1 Analysis by dwelling characteristics A2.1.2 Analysis by household characteristics and heating patterns A2.2 High electricity consumers A2.2.1 Analysis by dwelling characteristics A2.2.2 Analysis by household characteristics and appliance use A3 Conclusions Glossary References... 49

6 1 Introduction The main aim of the 211 Energy Follow-Up Survey (EFUS) was to collect new data on domestic energy use, in order to update the current modelling assumptions about how energy is used in the home, and to inform energy efficiency policy. The 211 EFUS consisted of a follow-up interview survey of a sub-set of households first visited as part of the 21/211 English Housing Survey (EHS). Additionally, sub-samples of these households were selected to have temperature loggers and electricity consumption monitors installed. A further stage of the EFUS was the compilation of gas and electricity consumption data from meter readings. Gas use in dwellings is predominantly for space heating. For electricity consumption, apart from those households with electric main heating systems, usage is likely to be additionally influenced by the number of persons in the household (higher consumptions arising from larger household numbers) as electricity use is predominantly for lights and appliances. This report focuses specifically on the analysis of the average (median) gas and electricity consumption values derived from meter readings taken primarily as part of the EHS 21/11 survey and the 211 EFUS. Analysis is based on the meter reading sub-sample weighted to the national level, using a weighting factor specific to the meter reading sub-sample. The results presented in this report are therefore representative of the English housing stock, with a population of 21.9 million households. The outcomes of this analysis will be used to inform energy efficiency policy and the data will be used in a wider context in conjunction with other EFUS outputs. Specific questions regarding metered energy use that this report will cover include: What are the typical measured gas and electricity consumptions per household in 211? How is the average consumption influenced by different household demographics? What effect does household income have on average energy consumption? How do physical dwelling characteristics and location affect the average energy required by the household? Is there a clear association between the energy efficiency of a dwelling and the average amount of energy used by its occupants? The annex to this report (Annex A) provides a focus on High Energy Users. This combines the information obtained from the household interview survey and the temperature monitoring data in order to investigate if certain types of households are more likely to be high energy consumers. A key component of this analysis process has been the linkage of the EFUS data to key dwelling and household descriptor variables collected in the interview and physical survey components of the 21 English Housing Survey (EHS). In this report, and the majority of the companion reports in this EFUS series, simple bivariate comparisons between the variable under consideration and individual descriptor variables have been performed in order to provide preliminary results and identify 1

7 bivariate trends. It should be recognised, however, that subsequent investigations using more sophisticated statistical analysis may assist in the interpretation of results. 2

8 2 Methodology A summary of the methodology of particular relevance to this report is provided below. Additional details, including the full interview questionnaire, can be found in the EFUS 211 Methodology report. The EFUS 211 interview survey was undertaken by interviewers from GfK NOP between December 21 and April 211. A total of 2,616 interviews were completed, drawn from a sample of addresses provided from the first three quarters of the 21/11 English Housing Survey (EHS). A further stage of the EFUS was the collection of consumption data from meter readings. For each household an initial meter reading (taken during the period April to September 21) and a final meter reading (taken during the period February to November 212) were obtained. Further detailed information on the EFUS 211 methodology, and the production of meter reading data, can be found in the EFUS 211 Methodology Report. In order to obtain a final set of cases for reporting, a validation process was applied to the meter readings from all sources. Cases with a missing first or second reading were removed (1,162 cases) and the remaining data were inspected to decide on the validity of their consumption data, including day and night rates of electricity where applicable. Cases were dropped (19 cases) where the consumption was implausibly high or produced a negative figure, although in a number of cases the data could be consolidated and retained where there was clear evidence for the source of the discrepancy, e.g. a negative value resulting from a meter passing through 9999 during the consumption period. This process was assisted by comparison with the Meter Point (MPAN/MPRN) data held by DECC. Following this validation, a complete set of initial and final electricity meter readings was obtained for 1,345 cases (51% of total EFUS sample). Of these, 1,197 cases had a mains gas supply and produced valid gas consumption values (89% of the meter reading sample, and 45% of the total EFUS sample). This dataset covered a range of consumption periods from around 15 months to around 3 months, depending on the date of the original EHS survey and meter reading and the source of the second reading. The final dataset required annual consumption figures for each case in which seasonal differences in energy use were accounted for. For example, if two cases covering 15 months with a 12 month overlap returned the same consumption, but one had the additional three months in summer and the other the additional three months in winter, then a direct comparison would not be possible. A simple seasonal annualisation was achieved by calculating the cumulative number of degree days for the whole consumption period of each case and for a core 12 month period (15 th November 21 to 14 th November 211) covering all the cases, finding the ratio of the degree day totals and finally multiplying each consumption figure for the full period by this ratio 2. This includes a very cold period in December 21, which acts to raise consumption of the EFUS data when compared to other estimates which do not include this month (e.g. the Digest of UK Energy Statistics data for 211). No weather correction of the data (i.e. to adjust to a typical year s weather ) was 2 Numerous alternatives to the degree day adjustment described are possible. However, testing of the effect of some alternatives suggests that the median consumptions of groups are not strongly influenced by the choice of approach. 3

9 carried out. See the EFUS Methodology Report for further details of the seasonal annualisation method. 2.1 Weighting factors Weighting factors specific to the sample of 1,345 households that had valid initial and final electricity meter readings were derived using logistic regression based on the profile of respondents for the GOR, tenure, dwelling type and working status of household. The results presented in this report are therefore representative of the English housing stock, with a population of 21.9 million households. Although the objective of the weighting factor is to provide totals that can be interpreted at the national level, readers should be aware that there may remain some uncorrected bias in the data (e.g. if the households that had valid meter readings differ from the population in a way that is not visible to the weighting procedure). 4

10 3 Findings Below are the key headline findings from the meter reading data recorded as part of the EFUS survey. Note that all average gas consumptions apply only to those dwellings with a gas meter (a sample of 1,197 cases) while average electricity consumption is calculated on the whole sample (1,345 cases). 3.1 Average consumption values The meter reading data reveal a wide range in energy consumption across the household stock. For gas, consumption values range from a minimum of 3 kwh and a maximum of 76,5 kwh. As can be seen from the histogram in Figure 1, there is considerable tailing of values towards the higher consumption values which results in a mean annualised gas consumption for all households of 16,2 kwh 3 but a median value of 14, kwh. For the electricity consumption data, the consumption values range from a minimum of 4 kwh and a maximum of 35,1 kwh and, as is seen with the gas consumption, the frequency distribution (Figure 2) shows considerable tailing towards the higher electricity consumption values which results in a mean annualised electricity consumption for all households of 4,9 kwh but a median value of 3,7 kwh. In order to give a reasonable comparison across categories within typical dwelling and household groups, the report will use the median values throughout. These headline figures compare well with DECC s National Energy Efficiency Data-Framework (NEED) 29 and 21 summary analysis 4 and Powering the Nation from EST 5, which focuses on electricity consumption. The NEED report quotes median values of 14, kwh for gas and 3,5 kwh for electricity, while Powering the Nation uses a mean, rather than a median, of 3,638 kwh, although the latter report excludes from its sample dwellings that use electricity for heating. The EFUS mean consumption, however, is higher than that reported by the Energy Consumption in the UK 6 for 211. However, these differences can largely be explained through the different periods covered by these datasets, and in particular the inclusion of the cold December 21 in the EFUS data. If households using electricity as their main heating fuel (6% of households) are excluded from the EFUS analysis, the mean electricity consumption is 4,7 kwh (down from 4,9 kwh for all households) but the median consumption remains the same as for all households at 3,7 kwh. Some households also use electric heaters to provide secondary heating, either as an alternative to the main heating system (12% of all households) or supplementary to it (22% of all households) (see the EFUS 211 Secondary Heating report). It should also be noted that there are a small percentage of dwellings (1.8%, sample size=21) with a mains gas supply that do not use it as the primary heating fuel. The analysis that follows was undertaken with the objective of giving an overview of household consumption values for the whole stock further work is required to provide household consumption values split by the primary and secondary heating characteristics. 3 All consumption estimates are rounded to the nearest 1 kwh

11 Figure 1: Distribution of annual gas consumption % of dwellings with gas Gas consumption (2 kwh bands) Base: All dwellings with gas in EFUS 211 meter reading sample (n=1197) Figure 2: Distribution of annual electricity consumption 25 % of dwellings with electricity Electricity consumption (1 kwh bands) Base: All dwellings in EFUS 211 meter reading sample (n=1345) 6

12 Table 1 shows the range of consumption values within each decile band 7 for gas and electricity. It can be seen that approximately 8% of households use between 5,9 to 28, kwh of gas per annum and between 1,8 and 8,8 kwh of electricity per annum. Table 1: Range of gas consumption for each decile band Range of gas consumption in band (kwh) Range of electricity consumption in band (kwh) 1st decile (lowest) 25-5,8 4-1,8 2nd decile 5,9-8,6 1,8-2,2 3rd decile 8,6-1,3 2,2-2,7 4th decile 1,3-12,5 2,7-3,2 5th decile 12,5-14, 3,2-3,7 6th decile 14, - 16,1 3,7-4,3 7th decile 16,1-18,5 4,3-5, 8th decile 18,5-21,5 5,-6,2 9th decile 21,6-28, 6,2-8,8 1th decile (highest) 28, - 76,5 8,8-35,1 Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) 3.2 Variation in household consumption patterns by dwelling characteristics It is of interest to energy efficiency policymakers to investigate whether energy consumption varies for different household and dwelling groups. Characteristics relating to the physical properties of the dwelling, (e.g. dwelling age and type, location and level of insulation,) have been examined and Table 2 shows the median gas and electricity consumptions and 95% confidence intervals 8 of the median consumption across a range of dwelling groups. The 95% confidence intervals show the significance of the differences across categories. Also shown are boxplots showing the median, the interquartile range (box) and the 1 th and 9 th percentile (extent of the whiskers). These boxplots provide an indication of the variability found within each category, although as per the objectives of this report, the discussion is limited to an analysis of the differences in median values. Detailed descriptions of the variables used or derived from the EHS and EFUS data can be found in the Glossary. 7 the consumption values were divided into 1 bands with equal number of households. Raw sample sizes are 117 cases in the top 1% of gas consumers and 129 cases in the top 1% of electricity consumers. 8 95% confidence intervals around a median value have been calculated following the method described by McGill et al, 1978 using a Design Factor of 1.1. See the Methodology Report for further details. 7

13 Table 2: (and 95% confidence intervals) gas and electricity consumption across various dwelling groups Dwelling characteristic Characteristic category Sample size Annual Gas consumption (kwh) 95% CI of the median Sample size Annual Electricity consumption (kwh) 95% CI of the median Dwelling type End terrace ,4 (121, 148) 146 3,8 (33, 42) Mid terrace ,9 (118, 14) 223 3,4 (31, 37) Semi detached ,5 (146, 163) 387 4, (37, 43) Detached ,5 (182, 27) 255 4,6 (43, 5) Bungalow ,1 (12, 142) 141 2,9 (26, 32) Flat 15 8,8 (78, 98) 193 2,8 (25, 31) Dwelling type House or bungalow ,9 (144, 155) ,9 (37, 4) Flat 15 8,8 (78, 98) 193 2,8 (25, 31) Dwelling Age Pre ,3 (125, 16) 26 4, (36, 45) ,1 (16, 183) 232 4,1 (38, 44) ,1 (122, 14) 326 3,6 (33, 39) ,2 (131, 153) 21 3,4 (3, 37) ,1 (93, 129) 92 3,2 (28, 37) ,7 (119, 156) 18 3,4 (29, 39) Post ,3 (18, 137) 171 4, (37, 44) Useable floor area Region - EHS order Urban or rural location? Type of heating system < 5 m ,7 (77, 97) 133 2,5 (21, 29) 5 to 69 m ,5 (98, 113) 292 2,9 (27, 32) 7 to 89 m ,6 (129, 143) 396 3,5 (33, 38) 9 to 19 m ,6 (146, 167) 199 4, (37, 43) 11 to 139 m ,3 (177, 28) 154 4,3 (4, 46) 14 m ,5 (217, 253) 171 5,5 (5, 6) North East 91 15,5 (138, 171) 98 3,5 (29, 4) North West 29 15,2 (139, 166) 219 3,7 (34, 41) Yorkshire and the ,9 (146, 172) 183 3,6 (33, 39) Humber East Midlands 81 15, (131, 169) 95 3,9 (34, 44) West Midlands ,9 (122, 156) 128 4,2 (37, 47) East 13 13,3 (118, 148) 158 3,2 (29, 36) London 12 13,6 (116, 155) 134 3,5 (3, 4) South East ,7 (126, 149) 183 4, (36, 44) South West 113 1,2 (88, 115) 147 3,8 (33, 43) Urban , (134, 145) 129 3,6 (35, 38) Rural 63 14,4 (121, 167) 136 4,8 (42, 53) Central Heating ,2 (137, 147) ,7 (35, 38) Non-Central 25 3,9 (19, 59) 89 6,2 (52, 73) Heating Main fuel Mains gas ,1 (136, 146) ,6 (35, 37) Electricity 14 3,5 (2, 67) 78 6,7 (56, 77) Other (bott./bulk 7 2,5 (, 69) 89 4,5 (38, 52) gas,solid,oil,comml) Are the walls of Insulated ,5 (128, 142) 648 3,6 (34, 38) the dwelling Not insulated 63 14,4 (137, 152) 697 3,8 (36, 4) insulated? Loft insulation <5mm 63 14,4 (114, 175) 75 3,7 (31, 43) 5-149mm ,3 (145, 162) 525 4, (38, 42) 15+ mm 56 14, (132, 148) 611 3,7 (35, 39) Is dwelling fully Yes ,6 (13, 141) 138 3,7 (35, 38) double glazed? No ,7 (154, 18) 37 4, (37, 43) Dwelling All 3 insulation ,3 (113, 133) 253 3,5 (32, 37) insulation measures 2 insulation meas ,7 (139, 155) 43 3,8 (35, 4) 1 insulation meas ,3 (143, 163) 48 4, (38, 42) No insulation meas ,3 (144, 182) 147 4,2 (37, 47) 8

14 Energy efficiency (SAP9) rating less than 3 15 *7,6 *(4, 147) 35 *5,6 *(41, 71) 3 to ,3 (151, 175) 293 3,9 (36, 42) 51 to , (134, 146) 92 3,8 (36, 39) more than ,8 (76, 11) 115 2,7 (23, 31) Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) *sample responses are very small and subject to large sampling errors Consumption by dwelling type Table 2 and Figure 3 show the median consumption values for different types of dwellings. Households living in detached dwellings have significantly higher median consumption for both gas and electricity compared to any other dwelling type; conversely, households living in flats have significantly lower median consumption of both fuels compared to other dwelling types (with the exception of bungalows). Clearly, dwelling size is a key driver of the consumption pattern. Flats have a median consumption less than half that of detached houses (8,8 kwh and 19,5 kwh respectively). This pattern matches that reported in the NEED 21 report, with a median of 19,3 kwh for detached houses and 8,1 kwh for flats. The median electricity consumption for flats is close to that of bungalows, despite flats being significantly smaller on average. One possible explanation for this is the high proportion of electric heating found particularly in purpose built flats, with around 22% of flats using electricity for space heating compared with 6% of bungalows. Figure 3: Boxplots of household gas and electricity consumption values by dwelling type Gas consumption kwh per year 4, 35, 3, 25, 2, 15, 1, 5, End terrace Mid terrace Semi Detached Bungalow detached Flat Electricity consumption kwh per year 12, 1, 8, 6, 4, 2, End terrace Mid terrace Semi DetachedBungalow detached Flat Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) 9

15 3.2.2 Consumption by dwelling age It may be expected that fuel consumption would gradually decrease as the construction date of a dwelling becomes more recent due to improvements in energy efficiency standards, but Figure 4 shows a more complex picture. Households living in dwellings built between 1919 and 1944 show a significantly higher median gas consumption than those from other periods with a median of 17,1 kwh per year, a pattern that is also seen in the NEED 21 report. These households also have a higher median electricity consumption than households living in dwellings built between 1965 and 198. Figure 4: Boxplots of household gas and electricity consumption values by dwelling construction date Gas consumption kwh per year 4, 35, 3, 25, 2, 15, 1, 5, Electricity consumption kwh per year 12, 1, 8, 6, 4, 2, Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by floor area Consumption of both fuels is strongly correlated with dwelling floor area (Figure 3). For gas, the median consumption for each successive floor area band is significantly higher than the previous band, whereas for electricity, the differences are not as distinct although the median consumption in dwellings greater than 14m 2 is significantly higher than all smaller dwellings and the median consumption in the smallest dwellings (<5m 2 ) is significantly lower than in dwellings larger than 7m 2. 1

16 Figure 5: Boxplots of household gas and electricity consumption values by floor area Gas consumption kwh per year 45, 4, 35, 3, 25, 2, 15, 1, 5, less than 5 sqm 5 to 69 sqm 7 to 89 sqm 9 to to sqm sqm sqm or more Electricity consumption kwh per year 16, 14, 12, 1, 8, 6, 4, 2, less than 5 sqm 5 to 69 sqm 7 to 89 sqm 9 to 19 sqm 11 to 139 sqm 14 sqm or more Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by region and area type gas consumption is lower in the South West compared to all other regions. This result was also seen in the NEED 21 data where it was suggested that reasons may be due to warmer weather in the South-West or different types of properties. Further work to weather-correct the gas consumption values may be necessary before drawing any conclusions about the regional variations in gas consumption. electricity consumption is higher in the West Midlands compared to the Eastern region. There is no statistically significant difference in the median gas consumption between rural and urban areas. However, median electricity consumption is significantly higher in rural areas compared to urban areas, likely to be due to the large number of dwellings here without a gas supply. In these properties, in addition to lights and appliances, electricity is likely to be used either the main heating fuel or as a secondary fuel to an oil or solid fuel supply. 11

17 Figure 6: Boxplots of household gas and electricity consumption values by area type Gas consumption kwh per year 35, 3, 25, 2, 15, 1, 5, Urban Rural Electricity consumption kwh per year 14, 12, 1, 8, 6, 4, 2, Urban Rural Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by energy performance It may be expected that the measured fuel consumption is affected by the energy efficiency of the homes. Figure 7 presents an indicator of how energy consumption varies with levels of wall insulation, loft insulation and presence of double glazing the dwelling. The results are also presented in Table 2 above. Statistical uncertainty affects the conclusions that can be drawn from these results, with confidence intervals overlapping between estimates of consumption of different groups. There are no significant differences in the median consumption of either gas or electricity between dwellings with or without wall insulation, nor in dwellings with differing levels of loft insulation. However, dwellings that are fully double glazed have median gas consumptions that are lower than those dwellings which are not fully double glazed. The data has also been analysed according to the number of these measures each dwelling has. There is some evidence of lower median gas consumption with increasing levels of different insulation measures, although the only statistically significant difference can be seen between those dwellings with all the insulation measures having both lower gas and electricity consumption than dwellings with no insulation measures. In terms of gas consumption, the effect of the presence of good insulation on space heating is demonstrated by the 4, kwh difference between the medians for dwellings with none of the 12

18 measures and those with all three (although other occupancy and dwelling differences between all households will also have an effect in addition to insulation characteristics). Figure 7: Boxplots of household gas and electricity consumption values for different levels of insulation Gas consumption kwh per year 4, 35, 3, 25, 2, 15, 1, 5, All 3 insulation measures 2 insulation measures 1 insulation measure No insulation measures Electricity consumption kwh per year 12, 1, 8, 6, 4, 2, All 3 insulation measures 2 insulation measures 1 insulation measure No insulation measures Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Energy efficiency can also be considered by examining the SAP rating of different households, shown in Figure 8 and also presented in Table 2 above, with dwellings with higher SAP ratings being more energy efficient. The dwellings with the lowest median gas consumption are in the most energy efficient SAP rating band (>7) with increasing levels of consumption in dwellings as SAP ratings decrease. While building fabric efficiency is a factor in reducing fuel use in higher SAP rated dwellings, the dwelling type also contributes, with 59% of dwellings in the highest SAP band being flats and only 7% being detached houses. Large heat losses from detached houses help to contribute to lower SAP ratings. 13

19 Figure 8 Boxplots of household gas and electricity consumption values by SAP rating Gas consumption kwh per year Electricity consumption kwh per year 35, 3, 25, 2, 15, 1, 5, 12, 1, 8, 6, 4, 2, less than 3 3 to 5 51 to 7 more than 7 less than 3 3 to 5 51 to 7 more than 7 Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) *Sample responses for the <3 category are very small and subject to large sampling errors 3.3 Household consumption patterns Characteristics relating to the households living within the dwellings (e.g. pensioner present, household income level, tenure) have also been examined for differences in their median consumption levels. Table 3 shows the median (and 95% confidence intervals 7 of the median) consumption across a range of household groups. The 95% confidence intervals show the significance of the differences across categories. As in the previous section, boxplots are also shown to provide an indication of the variability found within each category and detailed descriptions of the variables used or derived from the EHS and EFUS data can be found in the Glossary. 14

20 Table 3: (and 95% confidence intervals) gas and electricity consumption across various household groups Household characteristic Characteristic category Sample size Annual Gas consumption (kwh) 95% CI of the median Annual Electricity consumption (kwh) Sample 95% CI of the size median Tenure Owner Occupied ,7 (151, 164) 862 4, (38, 42) Private rented , (92, 127) 144 3,2 (28, 35) Local Authority 16 1,1 (91, 11) 176 3,1 (28, 34) RSL ,3 (12, 125) 163 3,5 (31, 4) Household size Pensioner Present? ,5 (97, 112) 352 2,4 (22, 25) ,6 (137, 155) 514 3,6 (34, 38) ,6 (143, 17) 225 4,4 (4, 47) ,1 (158, 185) 167 4,7 (43, 51) 5 or more 81 17,8 (158, 197) 87 6, (53, 66) At least one person ,1 (132, 15) 553 3,2 (3, 34) of pensionable age No persons of ,9 (132, 145) 792 4, (38, 42) pensionable age At least one child ,8 (149, 168) 387 4,5 (42, 48) No children ,5 (129, 141) 958 3,3 (32, 35) Children Present? Age of HRP ,8 (16, 131) 152 3,2 (28, 36) ,9 (129, 15) 234 4,2 (38, 45) ,3 (14, 166) 257 4,6 (42, 5) ,4 (13, 158) 28 3,8 (35, 41) ,3 (13, 156) 26 3,3 (3, 35) 75 or more ,4 (12, 148) 162 2,7 (24, 31) Employment status of HRP and partner combined Annual gross income of the HRP and partner weighted quintiles Is anyone in the household at home during the day on a weekday? Underoccupying? In Fuel Poverty? LIHC definition 1 or more work full ,7 (14, 154) 646 4,1 (39, 44) time 1 or more work part 17 13,9 (12, 157) 116 3,7 (32, 41) time none working, one ,7 (128, 146) 448 2,9 (27, 31) or more retired none working and none retired 118 1,8 (9, 126) 135 3,6 (31, 41) 1st quintile (lowest) 241 1,2 (91, 112) 291 2,7 (25, 3) 2nd quintile 26 13,4 (125, 143) 285 3,3 (3, 36) 3rd quintile ,7 (116, 138) 254 3,5 (32, 38) 4th quintile ,2 (15, 173) 25 4,2 (39, 45) 5th quintile ,8 (166, 19) 265 4,6 (42, 49) (highest) No ,8 (13, 146) 514 3,8 (36, 41) Yes ,2 (136, 149) 831 3,7 (35, 38) Not underoccupying ,3 (128, 139) 867 3,8 (36, 39) Under-occupying ,9 (148, 17) 478 3,7 (34, 39) Not in fuel poverty ,8 (133, 144) ,7 (36, 39) In fuel poverty 9 16,7 (14, 194) 111 3,8 (3, 46) Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by tenure On average, owner occupiers consume significantly more gas than any other tenure and more electricity than the private rented or local authority tenures (see Figure 9). For both fuels, the 15

21 private rented, local authority and RSL tenures show no significant differences in their median annual consumption rates. Figure 9: Boxplots of household gas and electricity consumption values by tenure Gas consumption kwh per year 35, 3, 25, 2, 15, 1, 5, Owner Occupied Private rented Local Authority RSL Electricity consumption kwh per year 12, 1, 8, 6, 4, 2, Owner Occupied Private rentedlocal Authority RSL Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by household size Household size has a strong influence on fuel consumption as suggested in Figure 1. consumption of both gas and electricity increases as the number of occupants grows, with median gas consumption ranging from 1,5 kwh in a one person household to 17,8 kwh in households where there are at least 5 people and median electricity consumption ranging from 2,4 kwh to 6, kwh in single person to 5+ persons households. However for both fuels, the difference in consumption between households with 3 or 4 persons is not statistically significant at the 95% level, nor, for gas consumption only, between households with 3, 4 or 5+ persons. 16

22 Figure 1: Boxplots of household gas and electricity consumption values by household size Gas consumption kwh per year Electricity consumption kwh per year 4, 35, 3, 25, 2, 15, 1, 5, 14, 12, 1, 8, 6, 4, 2, or more or more Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by household type The median consumption values for mains gas and electricity for households with and without a pensioner present and households with and without a child present are shown in Figure 11. For gas, there is no significant difference in the median consumption of households with or without a pensioner present, however for electricity the median consumption is lower in households with at least one pensioner present compared to households with no pensioners present. For households with at least one child present, the median consumptions of both gas and electricity are higher than in households with at least one child present compared to households without any children. 17

23 Figure 11: Boxplots of household gas and electricity consumption values by pensioner present and children present Gas consumption kwh per year 35, 3, 25, 2, 15, 1, 5, At least one person of pensionable age No persons of pensionable age At least one child No children Electricity consumption kwh per year 12, 1, 8, 6, 4, 2, At least one person of pensionable age No persons of pensionable age At least one child No children Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by age of household reference person (HRP) Figure 12 shows the median consumption based on the age of the household reference person (HRP). Households in which the HRP is between years old have a statistically significantly higher median gas consumption than households in which the HRP is between years old; none of the differences between other age groups are statistically significant for median gas consumption. For electricity consumption, the median use by households in which the HRP is aged between years old is higher than all other age groups except households in which the HRP is aged between years old. 18

24 Figure 12: Boxplots of household gas and electricity consumption values by the age of the household reference person Gas consumption kwh per year Electricity consumption kwh per year 35, 3, 25, 2, 15, 1, 5, 14, 12, 1, 8, 6, 4, 2, or more or more Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by household employment status and income gas consumption is statistically significantly lower for households in which occupants are long-term sick and/or unemployed compared to households in which one or more persons are either working full time or are retired. electricity consumption is lower in households in which none of the occupants are working but one or more is retired compared to any of the other employment categories. The consumption patterns by household income quintile are shown in Figure 13. gas consumption is lower for households in the lowest income quintile compared to households in all other income quintiles with around 7,5 kwh separating the median gas consumption in the highest and lowest income quintiles. Households with incomes in the top two income quintiles also have a statistically higher median gas consumption than households in the first three income quintiles however there are no significant differences between median gas consumptions in households in quintile two compared to three, and quintiles four compared to five. In fact, a discrepancy in the pattern is shown by a fall in median gas consumption values between the second and third quintiles. Initial analysis suggests that this may be due to the higher proportion of single person households in full time work in the third quintile compared to the second. These households typically occupy smaller dwellings and therefore have a lower gas consumption. Multivariate analysis would be required to investigate this further. 19

25 The median electricity consumption increases as the income quintiles increase, however the difference is only statistically significant between the first income quintile and the top three income quintiles. The trend of higher use of both gas and electricity and higher incomes is what might be expected when considering the larger size of dwelling that might typically be associated with high incomes and the ability to afford higher fuel bills. In fact, the consequence of high income households living in larger homes can be seen by comparing Figure 13 with Figure 14. Here consumption has been normalised to the floor area of each dwelling, resulting in a fairly uniform median annual consumption of both fuels across the income quintiles. Figure 13: Boxplots of household gas and electricity consumption values by income quintiles Gas consumption kwh per year 4, 35, 3, 25, 2, 15, 1, 5, 1st quintile (lowest) 2nd quintile 3rd quintile 4th quintile 5th quintile (highest) Electricity consumption kwh per year 12, 1, 8, 6, 4, 2, 1st quintile 2nd quintile3rd quintile 4th quintile 5th quintile (lowest) (highest) Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) 2

26 Figure 14: consumption values per m 2 of dwelling floor area by income quintiles kwh per year per m st quintile (lowest) 2nd quintile 3rd quintile 4th quintile 5th quintile (highest) Income quintiles Gas consumption per m² Electric consumption per m² Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) Consumption by occupancy characteristics Table 3 shows that there are no significant differences in the median consumption values of either gas or electricity between households in which someone is in during the day and households in which no-one is in during the day. There is, however a difference in the median gas consumption for households which are considered to be under-occupied compared to those not under-occupying, as shown in Figure 15. There is a difference of around 2,5 kwh for median gas consumption values. The higher figure for those under-occupying is indicative of the extra space heating used by these households in typically much larger dwellings. The mean floor area for an under-occupied dwelling is 127m 2 compared with 76m 2 for those not under-occupying. There is no significant difference in the median electricity consumption between households under-occupying or not. 21

27 Figure 15: Boxplots of household gas and electricity consumption values by under-occupation indicator Gas consumption kwh per year 4, 35, 3, 25, 2, 15, 1, 5, Not underoccupying Underoccupying Electricity consumption kwh per year 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, Not underoccupying Underoccupying Base: All households in the metered consumption sub-sample (n=1197 for gas; n=1345 for electricity) 22

28 4 Conclusions The results of the analysis of fuel consumption from a subset of 1,345 dwellings of the EFUS 211 are presented in this report. The report presents analysis at the headline level, revealing key patterns in energy consumption across the stock. The main findings of the analysis are: The meter reading data reveal a wide range in energy consumption across the household stock. For gas, annualised consumption values ranged from a minimum of 3 kwh and a maximum of 76,5 kwh. For electricity, annualised consumption values ranged from a minimum of 4 kwh and a maximum of 35,1 kwh. For both fuels, the frequency distributions show considerable tailing towards the higher electricity consumption values, resulting in mean values that are considerably higher than the median values. The median annual mains gas consumption determined using the EFUS meter reading data is around 14, kwh, with a median value of around 3,7 kwh for electricity. 8% of households use between 5,9 to 28, kwh of gas per annum and between 1,8 and 8,8 kwh of electricity per annum. Significant differences are found in the median consumption levels for different categories of dwelling and household types. Gas use is closely linked to dwelling floor area as well as household size, with detached houses having a median gas consumption more than twice that found in flats. Electricity use appears related to the number of people in the household, with the data showing a median consumption of around 2,4 kwh for single people, compared with a figure of around 6, kwh where there are at least five people in the household. Households living in dwellings built between 1919 and 1944 show a significantly higher median gas consumption than those from other periods with a median of 17,1 kwh per year, a pattern that is also seen in the NEED 21 analysis. These households also have a higher median electricity consumption than households living in dwellings built betwen1965 and 198. There is no statistically significant difference in the median gas consumption of households living in rural or urban areas. However, median electricity consumption is significantly higher in households in rural areas compared to urban areas, likely to be due to the large number of dwellings here without a gas supply. In these properties, in addition to lights and appliances, electricity is likely to be used either the main heating fuel or as a secondary fuel to an oil or solid fuel supply. There are no significant differences in the median consumption of either gas or electricity between households living in dwellings with or without wall insulation, nor between households living in dwellings with differing levels of loft insulation. However, households living in dwellings that are fully double glazed have median gas consumptions that are lower than those households living in dwellings which are not fully double glazed. There is some evidence of lower median gas consumption with increasing levels of different insulation measures, although the only statistically significant difference can be seen between those 23

29 households living in well insulated dwellings (three insulation measures) having both lower gas and electricity consumption than households living in poorly insulated dwellings. On average, owner occupiers consume significantly more gas than any other tenure and more electricity than the private rented or local authority tenures. For both fuels, the private rented, local authority and RSL tenures show no significant differences in their median annual consumption rates. gas consumption is lower for households in the lowest income quintile compared to households in all other income quintiles with around 7,5 kwh separating the median gas consumption in the highest and lowest income quintiles. The median electricity consumption increases as the income quintiles increase, however the difference is only statistically significant between the first income quintile and the top three income quintiles. The trend of higher use of both gas and electricity and higher incomes is what might be expected when considering the larger size of dwelling that might typically be associated with high incomes and the ability to afford higher fuel bills and in fact, similar median values are found for all income groups when the consumption is normalised for floor area. There are no significant differences in the median consumption values of either gas or electricity between households in which someone is in during the day and households in which no-one is in during the day. In dwellings where the household is said to be underoccupying, those that are excessive in size for the number of occupants, the median gas consumption is significantly higher than where they are not under-occupying. This report has provided an overview of gas and electricity consumption across the housing stock. More specific analysis of high energy using households is presented in Annex A. Further analysis of how consumption varies by main heating system type and how households typically use them, and household underspending can be found in the EFUS 211 Main Heating Systems and EFUS 211 Household Underspend reports. 24

30 Annex A: Focus on High Energy Users Executive Summary This annex includes analysis which combines the information obtained from the household interview survey and the temperature monitoring data in order to investigate if certain types of households are more likely to be high energy consumers. For the purposes of this analysis, high gas consumers have been defined as those households with metered gas consumptions in the top 1% of weighted values obtained during the survey; the same has been done for high electricity consumers using the electricity consumption values. Analysis is based on the meter reading sub-sample weighted to the national level, using a weighting factor specific to the meter reading sub-sample. The results presented in this report are therefore representative of the English housing stock, with a population of 21.9 million households. The results from the EFUS survey show that households in the top 1% of gas consumers are all in dwellings using mains gas as their primary heating fuel and therefore it is the factors influencing the energy required for space heating that are of primary interest for gas consumption. It has previously been reported that dwelling size appears to be the strongest driver of energy consumption (DECC, 212). The EFUS data corroborates the trend that on average, higher gas consumptions were largely associated with larger dwelling floor areas whilst providing additional evidence to show that other factors must also play a role. For electricity consumption, apart from those households with electric main heating systems, electricity use is predominantly for lights and appliances and therefore usage is additionally influenced by the number of persons in the household (higher consumptions arising from larger household numbers). In order to try to understand any secondary influences outside of these major drivers, this analysis by dwelling and household characteristics has considered high users in terms of those households in the top 1% of weighted values of total gas consumption and total electricity consumption, as well as those households in the top 1% of weighted values of gas consumption per m 2 and electricity consumption per person. The results show that the two approaches (total versus normalised) reveal variations in the percentage of high consumers within the dwelling and household categories and that it is the analysis by the gas per m 2 and electricity per person consumptions that are most helpful in assessing the potential determinants of high energy use. In terms of gas consumption, the results suggest that the strongest determinants for households having the highest (total) gas consumptions are likely to be: Dwelling type, dwelling age, floor area, tenure, household size, age of HRP, household income quintiles and under-occupancy status. However, the underlying influence of floor area for some of these characteristics is clearly the key driver as many of the differences in the percentage of high (total) gas consumers across the categories within these characteristics disappear when the analysis is carried out on the gas consumption/m 2. 25