By Tina Perinotto
13 December 2011 – Built environment, stand up and take a modest bow. According to the federal government’s 2011 State of the Environment Report, there is threatening news on most of our ecological fronts, but despite 87 per cent of the population living in urban areas, the built environment has managed to reverse some of the most negative trends.
Among the good news is that consumption of resources in the built environment may be slowing, growth in traffic may be levelling and use of public transport is increasing.
There is also emerging evidence that energy and water use may be slowing thanks to better technology and better awareness of the need to reduce environmental impact.
In Melbourne for instance the use of public transport to get to work jumped a massive 35.1 per cent in the 10 years to 2006. It jumped 22.4 per cent in Brisbane and 12.4 per cent in Sydney
There’s good news on energy consumption
Household energy use has fallen by 5 per cent since 2005-06, reflecting more efficient use of energy.
Likely contributors include greater use of insulation. “In 2002, 57.5 per cent of Australian dwellings had insulation. By 2008, this had risen to 61.5 per cent.
Solar hot water is another, with the proportion of dwellings with solar hot water rising from 4.3 per cent to 7.1 per cent. The use of heaters fell from 80.5 per cent of dwellings with heaters to 77.4 per cent. However, coolers rose from 48.6 per cent to 66.4 per cent of dwellings.
Appliances is another area where a more considered approach has made an impact. “In 2008, energy efficiency was the major factor considered when replacing refrigerators, freezers, dishwashers and clothes dryers. (For washing machines, the predominant factor was water efficiency, and for heaters it was cost.)”
Waste generation and recovery
Australia has difficulty with information on waste, with waste collection systems fragmented, and currently no national approach to the collection of information, so a methodology has been developed.
Biggest generator of waste is Western Australia with 2665 kilograms per person. Tasmania had the lowest at 1057 kg.
On recovery rates, the Northern Territory had the lowest recovery rate (5 per cent) and the Australian Capital Territory had the highest (76 per cent).
Other broad factors in Australia’s environmental performance include:
While there have been “significant advances”, management approaches and responsibilities are often fragmented across Australian, state and territory, and local governments.
“This can hamper our ability to address the legacies of past pressures like land clearing, ongoing pressures like invasive species and emerging challenges like climate change. National leadership and commitment, together with the cooperation and coordination of all governments and stakeholders, including the Australian community, are important foundations for the future of Australia’s environment and heritage.”
Built environment faces many pressures although consumption may be slowing
The majority of Australians (87 per cent in 2006) live in urban areas. An increasing need for urban space and buildings, increasing traffic congestion and increasing consumption are affecting the livability and environmental efficiency of the built environment.
Traffic congestion, in particular, is of growing concern. However, growth in traffic may be levelling and use of public transport is increasing. Emerging evidence suggests that energy and water use may be slowing due to improved technology and better recognition of the need to reduce human environmental impact.
Australia’s built environment is diverse. There are significant pressures on this environment driven by population and economic growth, and climate change. An increasing need for space and buildings (our urban footprint), increasing traffic congestion and increasing consumption are affecting the livability and environmental efficiency of the built environment. T
Traffic congestion, in particular, is of growing concern. However, growth in traffic may be levelling, and use of public transport is increasing.
Residents are also concerned about the look and design of their cities; in the biggest cities, there are concerns about whether the cities are clean, well maintained and unpolluted.
Climate change is creating new risks by increasing the likelihood of weather-related events such as mega-storms.
Built environment consumes significant natural resources, although this may be improving.
The residents and industries of the built environment consume natural resources, including water, energy and land. Waste generation within the built environment also has an impact on the natural environment. However, emerging evidence suggests that increases in the use of energy and water may be slowing due to improved technology, and better understanding and recognition of the need to reduce human environmental impact.
Government initiatives aim to improve the uncoordinated management of the built environment.
Management of the built environment is characterised by complex arrangements involving all levels of government, as well as the private.
Recent initiatives of the Council of Australian Governments to reform capital city planning, as well as the National Urban Policy,seek to address this issue. There are also concerns that insufficient investment has been made in infrastructure.
Outlook for the built environment is mixed.
The expected increase in the physical size of cities and increased traffic congestion will have negative impacts, but these may be offset by improved management and more efficient use of natural resources.
The structure and condition of housing affect the livability of cities. The vast majority of Australian dwellings are separate houses (77 per cent in 2008). Flats make up 14 per cent of dwelling structures, and semidetached dwellings 9 per cent.
The proportion of separate houses fell slightly (by 1.4 per cent) between 1998 and 2008, offset by a commensurate increase in flats. Houses are typically brick — about 69 per cent of houses (78 per cent in capital cities) are brick veneer or double brick. About 13 per cent of houses are timber, and about 8 per cent are fibro cement.
The trend over time has been towards greater use of brick veneer. Houses are becoming larger on average; the proportion of houses with four or more bedrooms increased from about 23 per cent to about 37 per cent between 1994 and 2008.
For the most part, overcrowding is not an issue in houses. In 2008, only 2.6 per cent of houses were considered to have insufficient bedrooms, as assessed using the Canadian National Occupancy Standard, which is widely used internationally as an indicator of housing use.
In contrast, the 2006 census found that 41 per cent of all occupied private dwellings had two or more bedrooms above minimum household requirements, up from 34 per cent a decade earlier.
The number of people per dwelling has an impact on resource efficiency. In 2006, the number of people per occupied private dwelling was 2.6, down from 2.7 a decade earlier.
The size of houses has increased; a 2005 Australian Bureau of Statistics study found that the average floor area of new residential buildings increased by 37.4 per cent between 1994-95 and 2002-03 (from 149.7 square metres to 205.7 square metres).
More recent analysis suggests that the trend is continuing, with an average new house size of 215 square metres in 2008-09, purported to be the biggest in the world.
However, block size appears to be falling; the average site area of new houses in Australian capital cities decreased between 1993-94, when it was 802 square metres, and 2003-04, when it was 735 square metres.
Residents of capital cities generally felt that their cities had a good balance of housing types, with an average satisfaction rating of 62 per cent. The spread of responses was not very large, ranging from a rating of 52 per cent in Sydney to 68 per cent in Adelaide.
In 2007, the Bureau of Transport and Regional Economics calculated that the avoidable social cost of congestion in the capital cities was about $9.4 billion in 2005. (Avoidable social cost of congestion includes extra travel time and the accompanying loss of productivity; increased vehicle operating costs; and poorer air quality — because vehicles under congested conditions emit more noxious pollutants — leading to higher health costs.)
This was projected to increase to $20.4 billion in 2020. On a unit cost basis (cents per kilometre), the cost in 2005 ranged from less than two cents (in Darwin) to about eight cents (in Sydney), with a metropolitan average of about seven cents.
The impact of congestion, particularly in Australia’s largest cities, is causing concern. In Sydney, satisfaction with the road network and traffic congestion had a very low rating of 13 per cent, and low ratings were also recorded in Brisbane, Melbourne and Perth. Only in Canberra and Darwin were satisfaction ratings of more than 50 per cent recorded.
One way of reducing traffic congestion is to encourage the use of public transport and nonmotorised forms of travel. Public transport can improve urban amenity and reduce the land needed for roads and parking – land that may be put to more attractive uses. Public transport is also more energy efficient than car transport. The Census of Population and Housing , conducted every five years, asks all Australians about their means of travel to work.
On census day in 2006, 79 per cent of people travelled to work by motor vehicle, 11 per cent took public transport and 12 per cent rode a bicycle, walked, worked from home or took some other form of transport.
The proportion of people travelling by public transport was greatest in Sydney; very few people in smaller cities tended to use public transport (although these cities are less likely to suffer congestion problems). Use of nonmotorised travel to get to work was highest outside the major cities. However, the proportion of travel using public transport is increasing in most capital cities (Table 10.3).
Table 10.3 Percentage of adults using public transport as the main form of transport for usual trip to work or full-time study
|City||1996||2000||2003||2006||Change between 1996 and 2006a|
|Total capital citiesb||16.3||17.2||17.9||19.1||17.2|
a Represents the change in the proportion of adults using public transport for their usual trip to work or study b Excludes Darwin c Includes Darwin and all other places outside capital cities
Source: Australian Bureau of Statistics
By March 2009, the proportion of adults using public transport as the main form of transport for their usual trip to work or study had increased to 14.0 per cent.
For day-to-day trips other than to work or full-time study, the proportion of adults using public transport was 18.7 per cent, rising to 26.0 per cent in state capital cities.
These figures related to any use of public transport and not whether it was the main form. The main reasons given for not using public transport for usual trips to work or full-time study were lack of availability, and the convenience, comfort and privacy of a private vehicle.
The use of public transport is influenced by both personal preference and the quality of the available public transport service.
Australians have a poor view of the quality of public transport in the capital cities, with an average satisfaction rating of 36 per cent. Brisbane is considered the best (with 45 per cent), while Canberra is regarded as the worst (24 per cent). Sydney, which rates very poorly on traffic congestion, also rates relatively low (32 per cent) on the quality of public transport.
Urban environmental efficiency
Urban environmental efficiency relates to how well the built environment encourages the efficient use of natural resources—in particular, land, energy and water—and the implications of the built environment for waste production and minimisation.
Only limited data exist on the extent of land used by the built environment. The available data show that the built environment occupies only a small proportion of Australia. According to the Australian Collaborative Land Use Mapping Program, 14 031 square kilometres (0.18 per cent of Australia’s total area) were devoted to “urban intensive uses”.
There are currently no formal methods to detect and report land-use change nationally in Australia. However, it is clear that urban areas in Australia are continuing to grow in size. Land that is taken over for urban development is land that cannot be used for other purposes, and often this land has high environmental value.
In 2008-09, Australian households used 998 petajoules of energy—about 12 per cent of Australia’s total national energy use. About three-quarters (74 per cent) of household energy is obtained from secondary sources such as electricity and refined products, with the remaining quarter obtained from primary sources such as natural gas and LPG (liquefied petroleum gas).
There has been a trend towards increasing use of primary sources, mainly reflecting growth in household use of natural gas and LPG. Use of solar energy as a primary energy source by households is rather small, at 3.1 per cent in 2008-09 (up from 1.6 per cent in 2001-02).
Household energy use per person increased in the first part of the decade, peaking at 48.0 gigajoules per person in 2005-06. Since then, household energy use per person has fallen by about 5 per cent to 45.5 gigajoules, reflecting more efficient use of energy
Household energy use
One likely factor contributing to this fall is an increase in the use of insulation. In 2002, 57.5 per cent of Australian dwellings had insulation. By 2008, this had risen to 61.5 per cent. During the same period, the proportion of dwellings with solar hot water rose from 4.3 per cent to 7.1 per cent. The proportion of dwellings with heaters fell from 80.5 per cent to 77.4 per cent. Offsetting these factors was an increase in the proportion of dwellings with coolers, from 48.6 per cent to 66.4 per cent.
Households are tending to give greater consideration to energy efficiency when replacing appliances; in 2008, energy efficiency was the major factor considered when replacing refrigerators, freezers, dishwashers and clothes dryers. (For washing machines, the predominant factor was water efficiency, and for heaters it was cost.)
For other uses of energy (such as industry and transport), it is not easy to determine usage in the built environment separately from usage in other areas.
However, energy use in manufacturing may provide some information about energy use in the built environment, as manufacturing predominantly occurs within the built environment. In 2008-09, manufacturing was responsible for a little over one-third (35 per cent) of Australian national energy use, and almost 80 per cent of this was obtained from primary energy sources (mainly crude oil).
Since 2001-02, the intensity of energy use in manufacturing (measured as energy used per dollar of industry value added) has fluctuated; it was lower in 2008-09 than 10 years earlier. (Other factors such as changing industry structures may also affect intensity of manufacturing energy use.
Estimates of energy use – either by households or by industry on a comparable city-by-city or state-by-state basis are not readily available.
Waste generation and recovery
It is difficult to obtain comparable information on waste in Australia, both across time and across different states and territories. Waste collection systems are fragmented, and there is currently no national approach to the collection of information.
To overcome this problem, the Department of Sustainability, Environment, Water, Population and Communities engaged a consultant to develop a methodology for consistent interpretation of state and territory datasets and to produce a report, Waste and recycling in Australia 2011, based on this methodology.
The report found that waste generation per person in Australia was 2139 kilograms, ranging from 1057 kilograms per person in Tasmania to 2665 kilograms per person in WA.
The waste recovery rate for Australia was 52 per cent; the Northern Territory had the lowest recovery rate (5 per cent) and the Australian Capital Territory had the highest (76 per cent).
Between 2006–07 (the previous period for which data for Australia was available) and 2008–09, there appears to have been a 6 per cent increase in waste generation and a 7 per cent increase in recovery, suggesting that, at least for this period, growth in waste generation and waste recovery is proceeding at almost twice the rate of population growth.
Despite the data limitations, the available evidence suggests that, for earlier periods, the growth in waste generation also significantly exceeded growth in population.
The 2011 report provided estimates of waste generation and recovery by source sector (municipal, commercial and industrial, construction and demolition) for all states and territories.
Municipal waste, which approximates household waste, accounts for about one-third of waste generation. Queensland has the highest municipal waste generated per person (914 kilograms) and Victoria the lowest (441 kilograms).
Pressures on built environment have a high or very high impact.
Pressures from the need for more space due to population growth, and increasing consumption due to a growing, increasingly wealthy population, are considered to be particularly significant.
Traffic, pollution, extreme climate events and rising sea levels also place pressure on the livability and environmental efficiency of the built environment. Because the underlying drivers – population growth, economic growth and climate change– are all increasing, so too are the resultant pressures on the built environment.
Both population and economic growth typically cause increased traffic, which can increase traffic congestion.
Unless mitigated, traffic congestion tends to increase more quickly than the growth rates in the underlying drivers, because of the compounding effect that additional traffic has on traffic congestion.
Although estimating future traffic congestion can be difficult and complex because of the assumptions that need to be made, in 2009, the Bureau of Transport and Regional Economics projected a baseline increase in the avoidable social cost of congestion of 117 per cent between 2005 and 2020, compared with a projected increase of 37 per cent in total annual kilometres travelled in passenger-car equivalent units.
In comparison, the mid-range population projections in the 2010 intergenerational report produced by the Australian Government Treasury are for a population increase of 26 per cent between 2005 and 2020.
Using that report’s projected economic growth rate (an average annual increase of 2.7 per cent in gross domestic product [GDP]), GDP would increase by 49 per cent over the same period.
Both increased population and increased economic growth tend to lead to increased consumption. This, in turn, can increase the use of scarce natural resources such as water and energy, unless the rate of growth is offset by increases in the efficiency with which these resources are used.
There is evidence of recent significant increases in the efficiency of urban use of water, particularly by households, where total water use has fallen even though the population has been growing strongly.
However, it is not known how much of this is due to temporary factors, such as the recent prolonged drought across significant parts of Australia and consequent water restrictions, and how much relates to more permanent changes in the efficiency of water use.
Energy intensity also appears to be falling, at least in recent times, in terms of both household and manufacturing energy use; however, for households, the decrease in intensity has tended to only just offset the increase in population growth.
Increased population can also lead to increased waste, as a result of increased consumption associated with greater numbers of people and increased affluence due to higher incomes.
Waste generation has typically grown more quickly than the population, and this trend remains evident in the most recent data.
Recycling and energy recovery can mitigate the environmental impact of growth in waste generation. It appears that the tendency to recycle over time has been increasing, but the recovery rate has recently stabilized.
Increased extreme weather events
The built environment is vulnerable to weather events such as storms –particularly cyclones and hailstorms – and bushfires.
Although it is difficult to identify precise relationships between climate change and particular weather events, research by the Commonwealth Scientific and Industrial Research Organisation and the Bureau of Meteorology in 2007 suggests that climate change will lead to increases in:
The proportion of tropical cyclones in the more intense category, potentially affecting the built environment in coastal northern Australia hail risk over the south-east coast of Australia – the 1999 Sydney hailstorm is generally considered to be the most costly natural disaster in Australia’s history, in terms of private property damage fire weather risk– likely at most sites in south-eastern Australia.
Rising sea levels
Climate change is expected to lead to increases in sea level, with projections of a sea level rise of up to 1.1 metres by 2100. (This is the high scenario. The low scenario is for a rise of 0.5 metres, and the medium scenario is for a rise of 0.8 metres.)
Such a sea level rise, with an allowance included for a modelled high-tide event, could potentially expose 157 000 – 247 600 existing residential buildings to inundation; the 2008 replacement value of these buildings is estimated at $41–63 billion.