A telephone survey of domestic heating methods and fuels for New Zealand was carried out by Digipoll in October 2004. The purpose of the survey was to collect data on home heating and related variables across the whole of New Zealand for input into the Ministry for the Environment's Warm Homes Project. These data were also collected for specific urban areas where concentrations of suspended particles (PM10) currently exceed the national environmental standard. Those results are presented in Sections 3 to 33.
The national survey targeted 201 households randomly selected across the whole of New Zealand (Table 3.1). The number of households was estimated based on 2001 census data for occupied dwellings, extrapolated for 2004 based on Statistics New Zealand population projections. [Obtained from Statistics New Zealand, www.stats.govt.nz] These projections suggest a population increase for New Zealand of 35% by 2021. [High, medium and low population projections were estimated by Statistics New Zealand. The value used is the medium population projection.]
Tables 3.2, 3.3 and 3.4 show domestic heating methods and fuels used for the main living areas in New Zealand and seasonal variations in heating behaviour. The main methods of heating were electricity (57% of households), wood burners (38%) and gas (34%).
Of the 201 households surveyed across New Zealand, none used pellet burners for domestic heating. Results of domestic heating surveys for urban towns in New Zealand indicate that pellet burner use ranges from 0 to 3%. The proportion of households using pellet-style burners across the whole of New Zealand is likely to be less than the 6.9% sample error.
Of the households using wood burners, around 4% indicated year-round use of the burner, although fuel quantities diminished in the summer months (Table 3.4). The average number of days per weeks a wood burner was used also decreased – from six during the winter to two during the summer. Data relating to open fire use are less certain owing to the small number of respondents using open fires during the summer months.
The majority (72%) of the households using gas in New Zealand did not have flued gas systems (Figure 3.1). The age distribution of wood burners used in houses in New Zealand suggests that around 40% of existing burners are more than 10 years old, with only a quarter being installed within the last five years.
Figure 3.1: Distribution of flued versus unflued gas heating and age of wood burner, New Zealand
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 72% of all gas heating and Flued gas makes up 28%.
The second graph is divided by the age of wood burners. Post-1999 wood burners make up 24%, 1994-99 wood burners make up 33% and the remaining 43% of wood burner are Pre-1994.
Average winter month heating costs are shown in Table 3.5. These results indicate that more money is spent on electric heating than on other heating methods. Of those households using electric heating, around 33% use a fan heater and around 28% an oil column heater in their main living area (Table 3.6). Radiant heaters are also common (24%). The more efficient heat pumps are used by around 13% of households using electric heating in their main living area.
Around 80% of the households surveyed owned their house, with the remaining 20% living in rented accommodation. Results show that open fires were more commonly used in owner occupied houses rather than in rental properties, and wood burners were much less common in rented houses (Table 3.7). Figure 3.2 shows that over 60% of the houses were more than 60 years old. Results suggest that over 20% of the open fires had been installed within the last 10 years
Figure 3.2: Domestic heating method, by average monthly heating expenditure, house ownership, house age and number of bedrooms, New Zealand
Average heating cost per month (winter)
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 $117, gas $66, open fire, $61, wood burner $60 and Multi-fuel $73.
The second graph sets out heating methods divided by home tenure. For households living in rentals 150,483 use electric, 78,824 use gas, 35,829 use open fire, 71,659 use wood burners, 21,498 use multi-fuel and 7,166 use oil. For households living in their on house 666,424 use electricity, 408,4564 use gas, 50,161 use open fires, 472,946 use wood burners, 93,156 use multi-fuel and 21,498 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 18% electric, 18% gas, 9% wood burners, 19% multi fuel and 25% open fires.
- Heating methods for houses between 11 and 20 years old are 15% electric, 12% gas, 17% wood burners, 13% multi fuel and 0% open fires.
- Heating methods for houses between 21 and 40 years old are 33% electric, 26% gas, 38% wood burners, 31% multi fuel and 17% open fires.
- Heating methods for houses over 41years old are 25% electric, 34% gas, 26% wood burners, 38% multi fuel and 50% 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, 0% gas, 1% wood burner, 6% multi fuel and 0% open fire.
- Heating methods for houses with two bedrooms are 24% electricity, 9% gas, 12% wood burner, 13% multi fuel and 17% open fire.
- Heating methods for houses with three bedrooms are 35% electricity, 53% gas, 42% wood burner, 25% multi fuel and 42% open fire.
- Heating methods for houses with four bedrooms are 28% electricity, 31% gas, 30% wood burner, 31% multi fuel and 33% open fire.
- Heating methods for houses with five bedrooms are 4% electricity, 4% gas, 9% wood burner, 25% multi fuel and 8% open fire.
- Heating methods for houses with six bedrooms are 2% electricity, 0% gas, 1% wood burner, 0% multi fuel and 0% open fire.
Survey results suggest that around 10% of houses in New Zealand may have no insulation or basic energy efficiency measures (Table 3.8). Around 71% have ceiling insulation and 50% have wall insulation. Floor insulation was less common at 22% of houses. About 10% of houses were double-glazed and 23% had hot water cylinder wraps fitted. Twenty-six percent of households have only one of these energy efficiency options and 1% have all five measures.
A comparison of home heating methods for households with different incomes is shown in Table 3.10. The non-response rate for this question was high, at around 17%. This limits the use of these data because there may be an income bias in the non-respondents. However, results do indicate that a reasonable proportion of houses with open fires have an income of more than $50,000.
Tables 3.11 and 3.12 show the relationship between heating methods and the age of the dwelling and number of bedrooms, respectively.