A telephone survey of domestic heating methods and fuels for Wainuiomata was carried out by Digipoll in March 2005. This involved surveying 150 households within the 2001 census area unit (CAU) areas of Glendale, Parkway, Fernlea, Arakura, Homedale West and Homedale East.
Survey details are shown in Table 29.1. The number of households for 2004 was estimated based on 2001 census data for occupied dwellings, extrapolated for 2004 based on Statistics New Zealand population projections. [New Zealand Statistics 2004, www.stats.govt.nz] The latter suggest a population decrease for Wainuiomata of 1% by 2021. [High, medium and low population projections were estimated by Statistics New Zealand. The value used is the medium population projection.]
Table 29.1: Summary survey data, Wainuiomata
29.1 Home heating methods and fuels
The Digipoll survey was used to collect information on home heating methods and fuels for Wainuiomata. These data were collected for the purpose of evaluating the impact of variations in heating methods on air quality in Wainuiomata, in particular the extent of change required to achieve the national environmental standard for PM10. This section presents the results of the home heating survey for Wainuiomata largely in tabular form, in the expectation that these results will be of value in other assessments (eg, emission inventory studies).
Tables 29.2 and 29.3 show domestic heating methods and fuels used for main living areas in Wainuiomata houses, and seasonal variations in heating behaviour. The commonest methods of heating the main living area in Wainuiomata were electricity (41%) and gas (59%). Many households used more than one method of heating in their main living area.
Table 29.2: Domestic home heating methods and fuels, Wainuiomata
Only a third of households used wood burners to heat their main living area. A small proportion of these used their wood burners year round (Table 29.3). The quantities of fuel used per day during non-winter months was typically less than during the winter (Table 29.4). Data are not presented for all heating methods because there was a high non-response rate for questions relating to seasonal variations for some heating types.
Table 29.3: Monthly variations in heating behaviour and fuel use, Wainuiomata
Table 29.4: Estimated daily fuel use, by season, Wainuiomata
29.2 Insulation, cost of heating, income, and house age and size
In addition to collecting data for the purpose of evaluating the impact of variations in heating methods on air quality, information was collected on a number of variables relevant to the Ministry for the Environment's Warm Homes Project. Relevant data for Wainuiomata are presented in this section.
Figure 29.1 shows that the proportion of households using gas systems that are properly flued in Wainuiomata is around 60%. This compares to a national average of 24%.
The amount spent on heating for a winter month, by heating method, is shown in Table 29.5. Data were not available for open fire or multi-fuel burners because of the small number of respondents in these categories.
Figure 29.2 shows the average heating costs, home ownership, age of dwelling and number of bedrooms for households in Wainuiomata. Around 25% of the respondents in Wainuiomata were living in rental accommodation.
One factor influencing the amount spent on different heating methods is the ability of households using solid fuel burners to obtain wood free of charge. Figure 29.3 shows that just over 50% of the wood used on solid fuel burners in Wainuiomata is self-collected.
Figure 29.1: Distribution of flued versus unflued gas heating and age of wood burner, Wainuiomata
Text description of figure
There are two pie graphs. The first graph shows the distribution of flued and unflued gas heaters. Unflued gas makes up 40% of all gas heating and Flued gas makes up 60%.
The second graph is divided by the age of wood burners. Post-1999 wood burners make up 33%, 1994-99 wood burners make up 22% and the remaining 45% of wood burners are Pre-1994.
Table 29.5: Average monthly heating costs (winter), Wainuiomata
Figure 29.2: Domestic heating method, by average monthly heating expenditure, house ownership, house age and number of bedrooms, Wainuiomata
Average heating cost per month (winter)
House ownership
Age of dwelling
Number of bedrooms
Text description of figure
There are four bar graphs.
The first graph sets out the average heating cost per month in winter. Cost per month by heating methods are: electric $107, gas $84, open fire $0, wood burner $80, pellet burner $0, multi-fuel $0 and oil $0.
The second graph sets out heating methods divided by home tenure. For households living in rentals 437 use electric, 765 use gas, 73 use open fire, 437 use wood burners, 0 use pellet burners, 73 use multi-fuel and 0 use oil. For households living in their own house 1785 use electricity, 2477 use gas, 36 use open fires, 1384 use wood burners, 0 use pellet burners, 219 use multi-fuel and 0 use oil.
The third graph sets out the age of a dwelling using a particular method of heating.
- Heating methods for houses under 10 years old are 10% electric, 8% gas, 6% wood burners, 0% multi fuel and 0% open fires.
- Heating methods for houses between 11 and 20 years old are 5% electric, 9% gas, 10% wood burners, 0% multi fuel and 0% open fires.
- Heating methods for houses between 21 and 40 years old are 41% electric, 47% gas, 42% wood burners, 50% multi fuel and 33% open fires.
- Heating methods for houses over 41 years old are 43% electric, 33% gas, 34% wood burners, 38% multi fuel and 33% open fires.
The fourth graph sets out particular heating methods by the number of bedrooms.
- Heating methods for houses with one bedroom are 3% electricity, 3% gas, 0% wood burner, 0% multi fuel and 0% open fire.
- Heating methods for houses with two bedrooms are 10% electricity, 12% gas, 12% wood burner, 25% multi fuel and 33% open fire.
- Heating methods for houses with three bedrooms are 57% electricity, 58% gas, 54% wood burner, 38% multi fuel and 33% open fire.
- Heating methods for houses with four bedrooms are 23% electricity, 24% gas, 28% wood burner, 25% multi fuel and 33% open fire.
- Heating methods for houses with five bedrooms are 5% electricity, 2% gas, 6% wood burner, 13% multi fuel and 0% open fire.
- Heating methods for houses with six bedrooms are 2% electricity, 0% gas, 0% wood burner, 0% multi fuel and 0% open fire.
Figure 29.3: Proportions of fuel obtained free of charge versus bought, Wainuiomata
Text description of figure
This bar graph shows the amount of wood either bought or collected free of charge by three different types of heating.
Those using open fires bought 43% of their fuel, those using wood burners bought 45% of their fuel and those using multi-fuel burners bought 50% of their fuel.
Table 29.6: Type of electric heating, Wainuiomata
The commonest types of electric heater used in the main living area in Wainuiomata houses were oil column heaters and fan heaters (Table 29.6). A number of houses used more than one type of electric heater in their main living area.
Data on home heating methods, by house ownership, are shown in Table 29.7.
Table 29.7: Home heating method, by house ownership, Wainuiomata
Household insulation types and heating methods are shown in Tables 29.8 and 29.9. Around 79% of houses had ceiling insulation but only 44% had wall insulation. Around 23% of houses had at least three types of insulation.
Table 29.10 shows home heating method, by household income. The overall non-response rate was around 23%. This limits the interpretation of these data because there may be an income bias in the non-respondents.
Table 29.8: House insulation summary statistics, Wainuiomata
Table 29.9: Degree of house insulation, by heating method, Wainuiomata
Table 29.10: Home heating method, by household income, Wainuiomata
Tables 29.11 and 29.12 show the relationship between heating methods and the age of the dwelling and number of bedrooms, respectively.
Table 29.11: Home heating method, by age of dwelling, Wainuiomata
Table 29.12: Home heating method, by number of bedrooms, Wainuiomata
29 Wainuiomata
November 2005
© Ministry for the Environment