FEATURE ARTICLE: WATER AND ENERGY EFFICIENCY ELEMENTS OF HOUSEHOLDS IN OLDER AND NEWER DWELLINGS


INTRODUCTION

In recent years, climate change challenges have received increasing government focus. One challenge receiving particular focus is that of improving the environmental sustainability of households. This feature article explores sources of water and energy, insulation and energy use in residential dwellings and examines the differences and similarities between newer and older dwellings.

Internationally, sustainable development has been present in discourse for over two decades, with the 1987 United Nations report Our Common Future citing the importance of intergenerational equity for development (United Nations 1987). In 1998, the OECD named sustainable development a key priority and an overarching goal for its member countries (DEWHA 2008).

The 1992 Intergovernmental Agreement on the Environment between all levels of Australian government served to facilitate a cooperative national approach to the environment where economic and environmental considerations were to be integrated into decisions about development (DEWHA 2010a). Complementing the aim of sustainable development is the concern for the sustainability and livability of Australia's cities (Infrastructure Australia 2010).

Historically, Australian buildings have not been built with energy efficiency as a key concern (COAG 2009). However, since the early 2000s in Australia, there has been a focus on the environmental sustainability of new residential and commercial buildings. The National Framework for Energy Efficiency (NFEE), implemented in 2002 by the Ministerial Council on Energy, defines future directions for energy efficiency policy in Australia. In 2004, national minimum design standards for the energy efficiency of new residential buildings and renovations were set as part of the NFEE. In conjunction with the Australian Building Codes Board, a new five star energy efficiency standard for new buildings was introduced under NFEE in 2007 (Ministerial Council on Energy 2007).

In 2009 the Council of Australian Government (COAG) introduced the National Strategy for Energy Efficiency, which built on the NFEE to encourage and support innovation in energy efficiency technologies and approaches. Under the strategy, minimum energy efficiency standards will be nationally upgraded to six stars, or equivalent, from 2011.

A building's star rating (out of 10) depends on the layout of the home, the construction of its roof, walls, windows and floor, the orientation of windows and shading to the sun's path and local breezes and how well these suit the local climate. A five star rating indicates good, but not outstanding, thermal performance (DEWHA 2010b). Certain states, such as NSW and Victoria, expanded on these requirements and stipulated further measures to meet their standards.

In 2005 the Victorian government was the first state to implement the five star standard for all new homes, which was extended in 2008 to include renovations and relocations of homes. At the time of the survey, to meet energy efficiency and water management standards, new Victorian residential buildings and renovations required a five star energy rating for the building fabric (as stipulated by the NFEE), water saving taps and fittings, and the installation of either a rainwater tank for toilet flushing or a solar hot water service. While insulation was not mandatory, it was recommended as the best way to improve a building's energy efficiency (Building Commission 2004).


CHARACTERISTICS FOR NEWER AND OLDER DWELLINGS

Across Australia, data from the Survey of Income and Housing showed that 8.9% of first home owners with a mortgage bought a new dwelling in 2007-08, down from 23% in 1995-96 (ABS 2009). The average value of a new dwelling in Victoria in 2007-08 was $446,300 and $333,900 for an established dwelling (ABS, Customised data from the Survey of Income and Housing, 2007-08, 2010). In 2008, around a third (31%) of all private sector building approvals in Australia were in Victoria, the highest of all the states (ABS 2010).

Of the 2.1 million households in Victoria in 2009, 2.0 million (96%) lived in older dwellings (more than two years old as at October 2009) and 80,300 (3.8%) lived in newer dwellings (two years old or less as at October 2009). Of the households in newer dwellings, 63,100 were in Melbourne Major Statistical Region and 17,200 were in the remainder of Victoria.

It must be noted that due to the small number of households in newer dwellings in relation to households in older dwellings, the actual numbers for these variables were higher for households in older dwellings. However, proportions have been used in the analysis in order to gain a greater understanding of the trends for households in newer dwellings as compared to households in older dwellings.

In Victoria, households that lived in newer and older dwellings showed similarities for some characteristics and differences for others. The proportion of households were similar regardless of whether they lived in a newer or older dwelling across all income brackets, whether or not the household had children, and for all household sizes, as seen in table 1.

Household Characteristics, Victoria - 2009
		Dwelling age
		Older dwellings(a)	Newer dwellings(b)
Household Characteristics		%	%
Income
	Less than $25,000 per year	22.4	18.8
	$25,000 to less than $50,000 per year	21.1	22.6
	$50,000 to less than $70,000 per year	15.7	11.9
	$70,000 to less than $110,000 per year	19.9	20.1
	$110,000 or more per year	16.3	18.7
Household size
	One person household	24.9	23.2
	Two person household	32.6	34.5
	Three to five person household	39.6	39.3
Whether children in the household
	Children 0-14 years	27.2	29.0
	No Children 0-14 years	72.8	71.0
(a) Dwelling that household resided in was more than two years old at October 2009.
(b) Dwelling that household resided in was two years old or less at October 2009.
Source: Household Water, Energy Use and Conservation, Victoria, Oct 2009 (cat. no. 4602.2).

However, there were some differences for the proportions of households in older and newer dwellings in relation to dwelling type and tenure type, as seen in table 2.

For Victorian households, 78% lived in separate houses and the remaining 22% lived in semi-detached dwellings, row or terrace houses, town houses, apartments, flats or units (hereafter known as semi-detached dwellings or apartments). This was similar for households in older dwellings (79% and 21% respectively) but for households in newer dwellings, 55% lived in separate houses and 45% lived in semi-detached dwellings or apartments.

There was a similar occurrence for tenure type where households in older dwellings followed the Victorian trend, but households in newer dwellings differed somewhat. 72% of households in older dwellings owned their dwelling outright or were paying it and 26% were renting (including rent free) whereas for households in newer dwellings, 58% owned the dwelling outright or were paying it off and 40% rented.

Household Characteristics, Victoria - 2009
		Dwelling age
		Older dwellings(a)	Newer dwellings(b)
Household Characteristics		%	%
Dwelling type
	Separate house	79.4	54.7
	Flat, unit or apartment, semi-detached etc	20.5	45.3
Tenure type
	Owned outright	37.1	19.2
	Being paid off	35.1	38.4
	Rented (including rent free)	25.7	39.5
(a) Dwelling that household resided in was more than two years old at October 2009.
(b) Dwelling that household resided in was two years old or less at October 2009.
Source: Household Water, Energy Use and Conservation, Victoria, Oct 2009 (cat. no. 4602.2).

As households in newer dwellings were more likely than households in older dwellings to be renting or residing in semi-detached dwellings and apartments, this may have impacted the results when looking at water and energy sources and use by dwelling age. Overall, rented dwellings and semi-detached dwellings and apartments were less likely to have a rain water tank and insulation, two areas where households in newer dwellings had higher proportions than households in older dwellings. Due to high relative standard error, it was not possible to explore these relationships further.


ENERGY AND WATER EFFICIENCY ELEMENTS OF NEWER DWELLINGS

A greater proportion of households in newer dwellings had solar hot water systems, rainwater tanks plumbed into the dwelling and walls insulation than older dwellings.

Households in newer dwellings were more likely than households in older dwellings to have their rainwater tank plumbed into the dwelling. 25% of households in newer dwellings had a rainwater tank plumbed into their dwelling whereas 12% of households in older dwellings had the same. However, households in newer and older dwellings showed no statistically significant difference for having a rainwater tank overall (37% and 29% respectively).

Households in newer dwellings were more likely than older dwellings to have solar as a source of energy for heating water. 18% of households in newer dwellings had solar energy, compared with 3.8% of households in older dwellings.

Regulations state that all new Victorian dwellings cannot be approved without either a solar hot water system or a rainwater tank, which has been in effect since 2005. ABS estimates (above) were from a sample survey asking respondents whether or not the dwelling they resided in had these items. Statistics from 2008 new domestic building permits indicated higher rates of both solar hot water systems (28%) and rainwater tanks (47%), but at a similar ratio to ABS estimates (Building Commission 2009) (End Note 1) .

Households in newer dwellings with insulation (including households who had ordered but not yet installed insulation) were more likely to have insulated walls (69%) than households in older dwellings (30%) (End Note 2) . In nearly all cases this was as well as having insulation in the roof or ceiling. However, overall, households in older and newer dwellings which had insulation made up similar proportions.




DIFFERENCES AND SIMILARITIES IN ENERGY AND WATER SAVING ELEMENTS OF OLDER AND NEWER DWELLINGS

Households in older and newer dwellings showed similar rates of having alternative sources to mains water. 51% and 48% respectively had self-extracted water (water that is extracted by the user (generally in-situ) including from surface waters (streams or dams) and groundwater bores). Of the two main types of alterative water sources, households in older dwellings were more likely to have grey water (31%) than households in newer dwellings (22%) but both had about a third with rainwater.

For energy sources, households in older and newer dwellings had similar rates of gas as an energy source (including mains gas and LPG or bottled gas). Households in older dwellings had 88% and households in newer dwellings had 86% with gas.

Households in older and newer dwellings had similar rates of insulation overall, with 72% of households in older dwellings and 75% of households in newer dwellings having insulation installed or ordered. Households in older and newer dwellings were equally likely to have roof or ceiling insulation (99%) (End Note 2) .



Households in older and newer dwellings differed in their reasons for installing insulation. Households in older dwellings were more likely than households in newer dwellings to state the main reason for installing insulation as to achieve comfort (52% and 36% respectively). Households in newer dwellings were more likely to state their main reason for installing insulation as building regulations and standards (43%) than households in older dwellings (8.5%). Households in newer dwellings also had a higher proportion who stated their main reason for installing insulation was to save on the costs of energy bills (12%) compared to households in older dwellings (5.8%).



Households in older and newer dwellings both showed rates of over 95% for households with a washing machine and refrigerator. They also had similar rates for clothes dryers and separate freezers, but households in newer dwellings were more likely to have a dishwasher (69%) than households in older dwellings (52%). 75% of households in older and newer dwellings had an air conditioner and used it for similar amounts during the summer months. Almost all of households in older and newer dwellings had televisions. A higher proportion of households in older dwellings had a cathode ray television (CRT) (analog) (74%) than households in newer dwellings (53%) whereas a higher proportion of households in newer dwellings had LCD and plasma televisions (50% and 36% respectively) than households in older dwellings (36% and 23% respectively).




CONCLUSION

Households in newer dwellings had higher rates of insulation installed in the walls, solar energy for the hot water systems and rainwater tanks plumbed into dwellings than households in older dwellings. However, households in older dwellings and newer dwellings show similar proportions of self-extracted water, mains gas, insulation overall, household white goods and appliances and air conditioner ownership and use. Households in newer dwellings were more likely to have the water and energy efficiency elements they needed to reach government building standards but beyond these measures they were quite similar to households in older dwellings.


END NOTES

1 Building commission data classified new domestic buildings as including all new building work for domestic use, including dwellings, where regulations make environmentally sustainable building inclusion mandatory, but also includes fences, swimming pools and garages. A building permit allows for up to two years to commence approved works. <back

2 Questions relating to the location of insulation in the dwelling and reasons for installing insulation were only asked of households in dwellings with insulation (including households who had ordered but not yet installed insulation) and who were not renting. <back


REFERENCES

Australian Bureau of Statistics (ABS), 2009, Housing Occupancy and Costs, 2007-08, cat. no. 4130.0, viewed 20 July 2010, <https://www.abs.gov.au/AUSSTATS/abs@.nsf/ProductsbyCatalogue/ABB5849D48BA5D7FCA2568A900139426?OpenDocument>.

ABS, 2010, Building Approvals, Australia, May 2010, cat. no. 8731.0, viewed 20 July 2010, <https://www.abs.gov.au/AUSSTATS/abs@.nsf/allprimarymainfeatures/C39F34E5D80607C4CA2577730022A5DC?opendocument>.

Building Commission, Better heating and cooling, 2004, 5 Star House, Building Commission, viewed 23 July 2010, <http://www.5starhouse.vic.gov.au/5_star_house_heating.htm>.

Building Commission, pulse° Building Intelligence 2008, 2009, Building Commission, viewed 20 July 2010, <http://www.pulse.buildingcommission.com.au/resources/documents/Pulse_Building_Intelligence_2008.pdf>.

COAG, National Strategy on Energy Efficiency, Draft Paper, 30 April 2009, COAG, viewed 23 July 2010 <http://www.coag.gov.au/coag_meeting_outcomes/2009-04-30/docs/National_strategy_energy_efficiency.pdf>.

DEWHA (Australian Government Department of the Environment, Water, Heritage and the Arts), Organisation for Economic Cooperation and Development (OECD), 13 November 2008, DEWHA, viewed 22 July 2010, <http://www.environment.gov.au/about/international/oecd/index.html>.

DEWHA, Intergovernmental Agreement on the Environment, 30 June 2010(a), DEWHA, viewed 22 July 2010, <http://www.environment.gov.au/about/esd/publications/igae/index.html>.

DEWHA, House Energy Ratings, NatHERS - Nationwide House Energy Rating Scheme, 10 January 2010(b), DEWHA, viewed 23 July 2010, <http://www.nathers.gov.au/eer/index.html>.

Ministerial Council on Energy (MCE), Communiqué, 14^th Meeting of the MCE, 13 December 2007, MCE, viewed 22 July 2010, <http://www.ret.gov.au/Documents/mce/_documents/14th_Meeting_Communique20071213144531.pdf>.