31 Napier

Survey details are shown in Table 31.1. 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 no change in the population of Napier between 2001 and 2021. [High, medium and low population projections were estimated by Statistics New Zealand. The value used is the medium population projection.]

Table 31.1: Summary survey data, Napier

31.1 Home heating methods and fuels

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

Tables 31.2 and 31.3 show domestic heating methods and fuels used for the main living areas in Napier houses, and seasonal variations in heating behaviour. The commonest methods of heating the main living area in Napier houses were gas (53%), electricity (42%) and wood burners (36%). Many households used more than one method of heating in their main living area. Coal use in Napier is minimal comprising, less than 1% of total fuel use by weight.

Table 31.2: Domestic home heating methods and fuels, Napier

Fuel use during the summer months is not common in Napier, with only a small proportion of households using multi-fuel burners to heat their homes during the summer months (Table 31.3). The quantities of fuel used per day during non-winter months was typically less than during the winter (Table 31.4). 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 31.3: Monthly variations in heating behaviour and fuel use, Napier

Table 31.4: Estimated daily fuel use, by season, Napier

31.2 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 Napier are presented in this section.

Figure 31.1 shows that the proportion of households using gas systems that are properly flued in Napier is around 38%. This compares to a national average of 24%.

The amount spent on heating for a winter month, by heating method, is shown in Table 31.5. In Napier, households typically spent on average $60–$90 per month.

Figure 31.2 shows the average heating costs, home ownership, age of dwelling and number of bedrooms for households in Napier. Around 25% of the respondents in Napier 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 31.3 shows that around 50% of the wood used on solid fuel burners in Napier is self-collected.

Figure 31.1: Distribution of flued versus unflued gas heating and age of wood burner, Napier

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 62% of all gas heating and Flued gas makes up 38%.

The second graph is divided by the age of wood burners. Post-1999 wood burners make up 18%, 1994-99 wood burners make up 29% and the remaining 53% of wood burners are Pre-1994.

Table 31.5: Average monthly heating costs (winter), Napier

Figure 31.2: Domestic heating method, by average monthly heating expenditure, house ownership, house age and number of bedrooms, Napier

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 $89, gas $68, open fire $0, wood burner $58, pellet burner $0, multi-fuel $61 and oil $0.

The second graph sets out heating methods divided by home tenure. For households living in rentals 1432 use electric, 2473 use gas, 651 use open fire, 1562 use wood burners, 0 use pellet burners, 260 use multi-fuel and 0 use oil. For households living in their own house 6767 use electricity, 7808 use gas, 1432 use open fires, 5466 use wood burners, 0 use pellet burners, 911 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, 6% gas, 7% wood burners, 0% multi fuel and 0% open fires.
• Heating methods for houses between 11 and 20 years old are 10% electric, 5% gas, 13% wood burners, 33% multi fuel and 0% open fires.
• Heating methods for houses between 21 and 40 years old are 16% electric, 14% gas, 15% wood burners, 22% multi fuel and 0% open fires.
• Heating methods for houses over 41 years old are 59% electric, 70% gas, 61% wood burners, 33% multi fuel and 94% open fires.

The fourth graph sets out particular heating methods by the number of bedrooms.

Heating methods for houses with one bedroom are 8% electricity, 4% gas, 0% wood burner, 0% multi fuel and 0% open fire.

Heating methods for houses with two bedrooms are 21% electricity, 24% gas, 20% wood burner, 22 multi fuel and 19% open fire.

Heating methods for houses with three bedrooms are 37% electricity, 42% gas, 48% wood burner, 56% multi fuel and 44% open fire.

Heating methods for houses with four bedrooms are 25% electricity, 23% gas, 26% wood burner, 11% multi fuel and 31% open fire.

Heating methods for houses with five bedrooms are 8% electricity, 5% gas, 6% wood burner, 11% multi fuel and 0% 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 31.3: Proportions of fuel obtained free of charge versus bought, Napier

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 39% of their fuel and those using multi-fuel burners bought 50% of their fuel.

Table 31.6: Type of electric heating, Napier

The commonest types of electric heating used in the main living area in Napier houses were oil column heaters and fan heaters (Table 31.6). 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 31.7.

Table 31.7: Home heating method, by house ownership, Napier

Household insulation types and heating methods are shown in Tables 31.8 and 31.9. Around two-thirds of houses had ceiling insulation but only 43% had wall insulation. Only 20% of houses had at least three types of insulation.

Table 31.10 shows home heating method, by household income. The overall non-response rate was around 21%. This limits the interpretation of these data because there may be an income bias in the non-respondents.

Table 31.8: House insulation summary statistics, Napier

Table 31.9: Degree of house insulation, by heating method, Napier

Table 31.10: Home heating method, by household income, Napier

Tables 31.11 and 31.12 show the relationship between heating methods and the age of the dwelling and number of bedrooms, respectively.

Table 31.11: Home heating method, by age of dwelling, Napier

Table 31.12: Home heating method, by number of bedrooms, Napier