30 Rotorua

Survey details are shown in Table 30.1. 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 for Rotorua of 8% by 2021. [High, medium and low population projections were estimated by Statistics New Zealand. The value used is the medium population projection.]

Table 30.1: Summary survey data, Rotorua

30.1 Home heating methods and fuels

The Digipoll survey was used to collect information on home heating methods and fuels for Rotorua. These data were collected for the purpose of evaluating the impact of variations in heating methods on air quality in Rotorua, 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 Rotorua largely in tabular form, in the expectation that these results will be of value in other assessments (eg, emission inventory studies).

Tables 30.2 and 30.3 show domestic heating methods and fuels used for the main living areas in Rotorua houses, and seasonal variations in heating behaviour. The commonest methods of heating the main living area in Rotorua were gas (44%), electricity (35%) and wood burners (34%). Many households used more than one method of heating in their main living area.

Table 30.2: Domestic home heating methods and fuels, Rotorua

A small proportion of households in Rotorua indicated that they used wood burners for home heating during November and December (Table 30.3). The quantities of fuel used per day during non-winter months was typically less than during the winter (Table 30.4). 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 30.3: Monthly variations in heating behaviour and fuel use, Rotorua

Table 30.4: Estimated daily fuel use, by season, Rotorua

30.2 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 Rotorua are presented in this section.

Figure 30.1 shows that the proportion of households using gas systems that are properly flued in Rotorua is around 45%. This compares to a national average of 24%.

The amount spent on heating for a winter month, by heating method, is shown in Table 30.5. No results were available for open fires, multi-fuel burners or pellet burners because of the small number of respondents for these categories.

Figure 30.2 shows the average heating costs, home ownership, age of dwelling and number of bedrooms for households in Rotorua. Around 23% of the respondents in Rotorua 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 30.3 shows that around 50% of the wood used on solid fuel burners in Rotorua is self-collected.

Figure 30.1: Distribution of flued versus unflued gas heating and age of wood burner, Rotorua

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 45% of all gas heating and Flued gas makes up 55%.

The second graph is divided by the age of wood burners. Post-1999 wood burners make up 20%, 1994-99 wood burners make up 34% and the remaining 46% of wood burners are Pre-1994.

Table 30.5: Average monthly heating costs (winter), Rotorua

Figure 30.2: Domestic heating method, by average monthly heating expenditure, house ownership, house age and number of bedrooms, Rotorua

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 $90, gas $75, open fire $8, wood burner $96, pellet burner $60, multi-fuel $0 and oil $0.

The second graph sets out heating methods divided by home tenure. For households living in rentals 1367 use electric, 1367 use gas, 114 use open fire, 1025 use wood burners, 0 use pellet burners, 683 use multi-fuel and 0 use oil. For households living in their own house 4669 use electricity, 6263 use gas, 683 use open fires, 4783 use wood burners, 228 use pellet burners, 569 use multi-fuel and 228 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 8% electric, 12% gas, 4% wood burners, 0% multi fuel and 0% open fires.
• Heating methods for houses between 11 and 20 years old are 21% electric, 27% gas, 16% wood burners, 18% multi fuel and 14% open fires.
• Heating methods for houses between 21 and 40 years old are 42% electric, 27% gas, 33% wood burners, 27% multi fuel and 43% open fires.
• Heating methods for houses over 41 years old are 26% electric, 27% gas, 43% wood burners, 9% multi fuel and 43% 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, 0% wood burner, 0% multi fuel and 0% open fire.
• Heating methods for houses with two bedrooms are 13% electricity, 10% gas, 8% wood burner, 9% multi fuel and 14% open fire.
• Heating methods for houses with three bedrooms are 58% electricity, 54% gas, 65% wood burner, 36% multi fuel and 57% open fire.
• Heating methods for houses with four bedrooms are 17% electricity, 25% gas, 25% wood burner, 36% multi fuel and 14% open fire.
• Heating methods for houses with five bedrooms are 8% electricity, 7% gas, 2% wood burner, 9% multi fuel and 14% open fire.
• Heating methods for houses with six bedrooms are 0% electricity, 0% gas, 0% wood burner, 0% multi fuel and 0% open fire.

Figure 30.3: Proportions of fuel obtained free of charge versus bought, Rotorua

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 50% of their fuel, those using wood burners bought 55% of their fuel and those using multi-fuel burners bought 50% of their fuel.

Table 30.6: Type of electric heating, Rotorua

The commonest types of electric heating used in the main living area in Rotorua houses were oil column heaters and fan heaters (Table 30.6). 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 30.7.

Table 30.7: Home heating method, by house ownership, Rotorua

Household insulation types and heating methods are shown in Tables 30.8 and 30.9. Around 73% of households had ceiling insulation but only 47% had wall insulation. Only 23% of houses had at least three types of insulation.

Table 30.10 shows home heating method, by household income. The overall non-response rate was around 25%. This limits the interpretation of these data because there may be an income bias in the non-respondents.

Table 30.8: House insulation summary statistics, Rotorua

Table 30.9: Degree of house insulation, by heating method, Rotorua

Table 30.10: Home heating method, by household income, Rotorua

Tables 30.11 and 30.12 show the relationship between heating methods and the age of the dwelling and number of bedrooms, respectively.

Table 30.11: Home heating method, by age of dwelling, Rotorua

Table 30.12: Home heating method, by number of bedrooms, Rotorua