A telephone survey of domestic heating methods and fuels for Mosgiel was carried out by Digipoll in November 2004. This involved surveying 150 households within the 2001 census area unit (CAU) area of Mosgiel.
Survey details are shown in Table 12.1. 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 increase of 4% by 2021. [High, medium and low population projections were estimated by Statistics New Zealand. The value used is the medium population projection.]
Table 12.1: Summary survey data, Mosgiel
12.1 Home heating methods and fuels
The Digipoll survey was used to collect information on home heating methods and fuels for Mosgiel. These data were collected for the purpose of evaluating the impact of variations in heating methods on air quality in Mosgiel, 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 Mosgiel largely in tabular form, in the expectation that the results will be of value in other assessments (eg, emission inventory studies).
Tables 12.2 and 12.3 show domestic heating methods and fuels used for the main living areas in Mosgiel houses, and seasonal variations in heating behaviour. Electricity was the most common method of heating the main living areas of houses in Mosgiel, with 59% of households using this method. Wood burners and multi-fuel burners were used by 32% and 23% of households, respectively. Many households used more than one method of heating in their main living area. Overall, 65% of households in Mosgiel used wood and 19% used coal for heating in their main living areas.
Table 12.2: Domestic home heating methods and fuels, Mosgiel
Table 12.3 shows that only a small proportion of households in Mosgiel heat their homes during the summer months. Those that do heat their homes during summer typically use gas and multi-fuel burners, and heat on around three days per week during the summer months. Data shown in Table 12.3 exclude information relating to seasonal variations in electricity use for domestic heating. This is because this information was collected for the evaluation of emissions from domestic heating to determine options for reducing PM10 emissions in urban areas of New Zealand. Electricity is treated as a zero emission source for this purpose.
Table 12.4 shows that the average daily fuel use per household during the non-winter months is less than the amount used per day during the winter. Data are not presented for all heating methods because of the small number of respondents for some categories.
Table 12.3: Monthly variations in heating behaviour and fuel use, Mosgiel
Table 12.4: Estimated daily fuel use, by season, Mosgiel
12.2 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 Mosgiel are presented in this section.
Figure 12.1 shows that in Mosgiel around 32% of households using gas have flued gas systems. This compares to a national average of around 28%.
The average amount spent on fuel for solid fuel methods in Mosgiel ranges from $31 for open fires to $405 per month for oil burners (Table 12.5).
The average heating costs, home ownership, age of dwelling and number of bedrooms for households in Mosgiel are shown in Figure 12.2.
One factor influencing the amount spent on different heating methods is the ability of households using wood burners to obtain wood free of charge. Figure 12.3 shows that generally over half of the wood used for home heating in Mosgiel is self-collected.
Figure 12.1: Distribution of flued versus unflued gas heating and age of wood burner, Mosgiel
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 64% of all gas heating and Flued gas makes up 36%.
The second graph is divided by the age of wood burners. Post-1999 wood burners make up 45%, 1994-99 wood burners make up 20% and the remaining 35% of wood burner are Pre-1994.
Table 12.5: Average monthly heating costs (winter), Mosgiel
Figure 12.2: Domestic heating method, by average monthly heating expenditure, house ownership, house age and number of bedrooms, Mosgiel
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 $113, gas $81, open fire $31, wood burner $105, multi-fuel $135 and oil $405
The second graph sets out heating methods divided by home tenure. For households living in rentals 220 use electric, 128 use gas, 92 use open fire, 110 use wood burners, 0 use pellet burners, 147 use multi-fuel and 0 use oil. For households living in their own house 1413 use electricity, 312 use gas, 183 use open fires, 771 use wood burners, 37 use pellet burners, 477 use multi-fuel and 110 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 16% electric, 13% gas, 13% wood burners, 0% multi fuel and 7% open fires.
- Heating methods for houses between 11 and 20 years old are 16% electric, 17% gas, 27% wood burners, 29% multi fuel and 7% open fires.
- Heating methods for houses between 21 and 40 years old are 28% electric, 25% gas, 23% wood burners, 29% multi fuel and 13% open fires.
- Heating methods for houses over 41years old are 36% electric, 29% gas, 31% wood burners, 35% multi fuel and 67% open fires.
The fourth graph sets out particular heating methods by the number of bedrooms.
- Heating methods for houses with one bedroom are 6% electricity, 8% gas, 0% wood burner, 0% multi fuel and 0% open fire.
- Heating methods for houses with two bedrooms are 30% electricity, 21% gas, 6% wood burner, 3% multi fuel and 13% open fire.
- Heating methods for houses with three bedrooms are 43% electricity, 46% gas, 52% wood burner, 53% multi fuel and 60% open fire.
- Heating methods for houses with four bedrooms are 17% electricity, 17% gas, 35% wood burner, 35% multi fuel and 27% open fire.
- Heating methods for houses with five bedrooms are 3% electricity, 4% gas, 4% wood burner, 9% multi fuel and 0% open fire.
- Heating methods for houses with six bedrooms are 0% electricity, 4% gas, 2% wood burner, 0% multi fuel and 0% open fire.
Figure 12.3: Proportions of fuel obtained free of charge versus bought, Mosgiel
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 53% of their fuel, those using wood burners bought 48% of their fuel and those using multi-fuel burners bought 41% of their fuel.
Table 12.6: Type of electric heating, Mosgiel
The main types of electric heater used by households in their main living area in Mosgiel were heat pumps, portable oil column heaters, radiant heaters and fan heating, which were each used by around 20% of households using electric heating (Table 12.6). The proportion of houses with heat pumps (24%) is higher than the national average (13% of households using electric heating in their main living area).
Detailed data on home heating method, by house ownership, are shown in Table 12.7.
Table 12.7: Home heating method, by house ownership, Mosgiel
Household insulation types and heating methods are shown in Tables 12.8 and 12.9. Around 9% of houses in Mosgiel report having no insulation. Table 12.10 shows household income, by heating method. Results suggest around 28% of respondents using open fires in Mosgiel had incomes greater than $50,000. Results for other heating methods are difficult to interpret because of the non-response rate (16% overall).
Table 12.8: House insulation summary statistics, Mosgiel
Table 12.9: Degree of house insulation, by heating method, Mosgiel
Table 12.10: Home heating method, by household income, Mosgiel
Tables 12.11 and 12.12 show the relationship between heating methods and the age of the dwelling and number of bedrooms, respectively.
Table 12.11: Home heating method, by age of dwelling, Mosgiel
Table 12.12: Home heating method, by number of bedrooms, Mosgiel
12 Mosgiel
November 2005
© Ministry for the Environment