26 Blenheim
A telephone survey of domestic heating methods and fuels for Blenheim was carried out by Digipoll in February 2005. This involved surveying 152 households within the 2001 census area unit (CAU) areas of Springlands, Mayfield, Blenheim Central, Whitney, Redwoodtown and Witherlea.
Survey details are shown in Table 26.1. 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 Marlborough District of 12% by 2021. [High, medium and low population projections were estimated by Statistics New Zealand. The value used is the medium population projection.]
Table 26.1: Summary survey data, Blenheim
26.1 Home heating methods and fuels
The Digipoll survey was used to collect information on home heating methods and fuels for Blenheim. These data were collected for the purpose of evaluating the impact of variations in heating methods on air quality in Blenheim, 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 Blenheim largely in tabular form, in the expectation that these results will be of value in other assessments (eg, emission inventory studies).
Tables 26.2 and 26.3 show domestic heating methods and fuels used for the main living areas in Blenheim houses, and seasonal variations in heating behaviour. The commonest methods of heating the main living area in Blenheim were electricity (61%) and wood burners (52%). Many households used more than one method of heating in their main living area.
Table 26.2: Domestic home heating methods and fuels, Blenheim
Most houses in Blenheim do not heat their homes during the summer months (Table 26.3). The quantities of fuel used per day during non-winter months were typically less than during the winter (Table 26.4). 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 26.3: Monthly variations in heating behaviour and fuel use, Blenheim
Table 26.4: Estimated daily fuel, use by season, Blenheim
26.2 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 Blenheim are presented in this section.
Figure 26.1 shows that none of the respondents in the Blenheim survey had flued gas heating systems. (While some households in Blenheim may have flued gas heating systems, the results suggest that it would only be a small proportion.)
The amount spent on heating for a winter month, by heating method, is shown in Table 26.5. In Blenheim, households heating using multi-fuel burners and gas spent less per month on average ($19 and $49, respectively) than those using other heating methods, on average.
Figure 26.2 shows the average heating costs, home ownership, age of dwelling and number of bedrooms for households in Blenheim. Only a small proportion (15%) of the respondents in Blenheim were living in rental accommodation. This compares with a national average of around 20%.
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 26.3 shows that around half of the wood used on solid fuel burners in Blenheim is self-collected.
Figure 26.1: Distribution of flued versus unflued gas heating and age of wood burner, Blenheim
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 100% of all gas heating and Flued gas makes up 0%.
The second graph is divided by the age of wood burners. Post-1999 wood burners make up 22%, 1994-99 wood burners make up 23% and the remaining 55% of wood burners are Pre-1994.
Table 26.5: Average monthly heating costs (winter), Blenheim
Figure 26.2: Domestic heating method, by average monthly heating expenditure, house ownership, house age and number of bedrooms, Blenheim
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 $100, gas $49, open fire $0, wood burner $85, pellet burner $71, multi-fuel $19 and oil $0.
The second graph sets out heating methods divided by home tenure. For households living in rentals 623 use electric, 2831 use gas, 57 use open fire, 736 use wood burners, 0 use pellet burners, 57 use multi-fuel and 0 use oil. For households living in their own house 4585 use electricity, 962 use gas, 396 use open fires, 3736 use wood burners, 57 use pellet burners, 509 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 33% electric, 32% gas, 10% wood burners, 10% multi fuel and 25% open fires.
- Heating methods for houses between 11 and 20 years old are 14% electric, 5% gas, 15% wood burners, 10% multi fuel and 13% open fires.
- Heating methods for houses between 21 and 40 years old are 26% electric, 27% gas, 28% wood burners, 40% multi fuel and 25% open fires.
- Heating methods for houses over 41 years old are 24% electric, 27% gas, 43% wood burners, 40% multi fuel and 38% open fires.
The fourth graph sets out particular heating methods by the number of bedrooms.
- Heating methods for houses with one bedroom are 0% electricity, 0% gas, 0% wood burner, 0% multi fuel and 0% open fire.
- Heating methods for houses with two bedrooms are 23% electricity, 41% gas, 13% wood burner, 0% multi fuel and 25% open fire.
- Heating methods for houses with three bedrooms are 47% electricity, 45% gas, 59% wood burner, 90% multi fuel and 25% open fire.
- Heating methods for houses with four bedrooms are 23% electricity, 14% gas, 22% wood burner, 10% multi fuel and 38% open fire.
- Heating methods for houses with five bedrooms are 3% electricity, 0% gas, 5% wood burner, 0% multi fuel and 13% open fire.
- Heating methods for houses with six bedrooms are 2% electricity, 0% gas, 1% wood burner, 0% multi fuel and 0% open fire.
Figure 26.3: Proportions of fuel obtained free of charge versus bought, Blenheim
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 56% of their fuel and those using multi-fuel burners bought 55% of their fuel.
Table 26.6: Type of electric heating, Blenheim
The commonest types of electric heating used in the main living areas in Blenheim houses were oil column heaters and heat pumps (Table 26.6). 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 26.7.
Table 26.7: Home heating method, by house ownership, Blenheim
Household insulation types and heating methods are shown in Tables 26.8 and 26.9. Most houses had ceiling insulation (82%) and around 60% had wall insulation. Around 31% of houses had at least three types of insulation.
Table 26.10 shows home heating method, by household income. The overall non-response rate was around 19%. This limits the interpretation of these data because there may be an income bias in the non-respondents.
Table 26.8: House insulation summary statistics, Blenheim
Table 26.9: Degree of house insulation, by heating method, Blenheim
Table 26.10: Home heating method, by household income, Blenheim
Tables 26.11 and 26.12 show the relationship between heating methods and the age of the dwelling and number of bedrooms, respectively.
