A telephone survey of domestic heating methods and fuels for Westport was carried out by Digipoll in October 2004. This involved surveying 153 households within the 2001 census area unit (CAU) area of urban Westport.
Survey details are shown in Table 7.1. 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 the Buller Region of 14% by 2021. [High, medium and low population projections were estimated by Statistics New Zealand. The value used is the medium population projection.]
Table 7.1: Summary survey data, Westport
7.1 Home heating methods and fuels
The Digipoll survey was used to collect information on home heating methods and fuels for Westport. These data were collected for the purpose of evaluating the impact of variations in heating methods on air quality in Westport, in particular the extent of change required to achieve the NES for PM10. This section presents the results of the home heating survey for Westport largely in tabular form, in the expectation that these results will be of value in other assessments (eg, emission inventory studies).
Tables 7.2 and 7.3 show domestic heating methods and fuels used for main living areas in Westport houses, and seasonal variations in heating behaviour. Multi-fuel burners and electric heating were the most common methods of heating the main living area and were used by 48% and 35% of households, respectively. Around 27% of the households used gas and 22% used wood burners. Many households used more than one method of heating in their main living area.
Table 7.2: Domestic home heating methods and fuels, Westport
Table 7.3 shows households using multi-fuel burners heat their houses during both the summer and winter months, averaging seven days per week for most months of the year. Table 7.4 shows that the amount of wood burnt per day during the summer months on multi-fuel burners was about half that burnt during the winter, but the daily coal use per burner was similar for both seasons.
Table 7.3: Monthly variations in heating behaviour and fuel use, Westport
Table 7.4: Estimated daily fuel use, by season, Westport
7.2 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 Westport are presented in this section.
Figure 7.1 shows that around 21% of households using gas in Westport used flued gas systems. This compares to a national average of 28%.
The amount spent on heating for a winter month, by heating method, is shown in Table 7.5. In Westport, households heating using wood burners and gas spent less on heating per month during the winter than households using other methods.
Figure 7.2 shows the average heating costs, home ownership, age of dwelling and number of bedrooms for households in Westport. 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 7.3 shows that around a quarter of the wood used on wood burners in Westport is self-collected, compared with around 60% for open fires and 45% for multi-fuel burners.
Figure 7.1: Distribution of flued versus unflued gas heating and age of wood burner, Westport
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 79% of all gas heating and Flued gas makes up 21%.
The second graph is divided by the age of wood burners. Post-1999 wood burners make up 17%, 1994-99 wood burners make up 34% and the remaining 49% of wood burner are Pre-1994.
Table 7.5: Average monthly heating costs (winter), Westport
Figure 7.2: Domestic heating method, by average monthly heating expenditure, house ownership, house age and number of bedrooms, Westport
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 $88, gas $52, open fire $68, wood burner $48, Multi-fuel $78 and oil $220.
The second graph sets out heating methods divided by home tenure. For households living in rentals 94 use electric, 52 use gas, 21 use open fire, 94 use wood burners, 0 use pellet burners, 83 use multi-fuel and 0 use oil. For households living in their on house 458 use electricity, 375 use gas, 125 use open fires, 260 use wood burners, 0 use pellet burners, 676 use multi-fuel and 21 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 15% electric, 17% gas, 6% wood burners, 12% multi fuel and 7% open fires.
- Heating methods for houses between 11 and 20 years old are 19% electric, 5% gas, 15% wood burners, 15% multi fuel and 7% open fires.
- Heating methods for houses between 21 and 40 years old are 34% electric, 22% gas, 32% wood burners, 26% multi fuel and 50% open fires.
- Heating methods for houses over 41years old are 30% electric, 51% gas, 41% wood burners, 41% multi fuel and 36% open fires.
The fourth graph sets out particular heating methods by the number of bedrooms.
- Heating methods for houses with one bedroom are 2% electricity, 2% gas, 3% wood burner, 3% multi fuel and 0% open fire.
- Heating methods for houses with two bedrooms are 23% electricity, 7% gas, 12% wood burner, 12% multi fuel and 14% open fire.
- Heating methods for houses with three bedrooms are 55% electricity, 73% gas, 59% wood burner, 64% multi fuel and 64% open fire.
- Heating methods for houses with four bedrooms are 17% electricity, 10% gas, 18% wood burner, 15% multi fuel and 21% open fire.
- Heating methods for houses with five bedrooms are 2% electricity, 7% gas, 6% wood burner, 4% multi fuel and 0% open fire.
- Heating methods for houses with six bedrooms are 2% electricity, 0% gas, 3% wood burner, 0% multi fuel and 0% open fire.
Figure 7.3: Proportions of fuel obtained free of charge versus bought, Westport
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 41% of their fuel, those using wood burners bought 73% of their fuel and those using multi-fuel burners bought 55% of their fuel.
Table 7.6: Type of electric heating, Westport
The main types of electric heating used by households in their main living area in Westport during 2004 were portable oil column heaters and fan heaters, which were used by 34% and 23% of households, respectively (Table 7.6). Around 9% of households using electricity used heat pumps in their main living area.
Detailed data on home heating method, by house ownership, are shown in Table 7.7.
Table 7.7: Home heating method, by house ownership, Westport
Household insulation types and heating methods are shown in Tables 7.8 and 7.9. Table 7.10 shows home heating method by household income. The overall non-response rate was around 18%. This limits the use of these data, because there may be an income bias in the non-respondents. However, from the responses given, at least 35% of households using open fires to heat their main living area in Westport earn over $50,000 per year.
Table 7.8: House insulation summary statistics, Westport
Table 7.9: Degree of house insulation, by heating method, Westport
Table 7.10: Home heating method, by household income, Westport
Tables 7.11 and 7.12 show the relationship between heating methods and the age of the dwelling and number of bedrooms, respectively.
Table 7.11: Home heating method, by age of dwelling, Westport
Table 7.12: Home heating method, by number of bedrooms, Westport
7 Westport
November 2005
© Ministry for the Environment