by Danielle McCartney
10 August 2009 – At the moment, half the world’s population lives in towns and cities. By 2030 it is estimated that the urban population will reach five billion, which is 60 per cent of the world’s population. Australia is one of most urbanised countries in the world with 64 per cent of us living in the most densely populated areas; far above the OECD average of 39 per cent. Australian cities are growing at a rate of around two per cent per year whilst rural populations are stabilising and, in many cases, declining. The resulting demand for housing is often met through the development of greenfield sites at the fringes of our cities, further fueling urban sprawl.
The need to create sustainable cities has evolved as a response to issues such as climate change, finite fossil fuel resources, population increase, loss of biodiversity, air, water and soil pollution, social inequality and over-consumption of resources. Sustainable urban villages aim to meet the current needs and anticipate the future needs of the community. They comprise well-designed comfortable buildings that require the minimum use of resources over their lifecycle. These sustainable neighbourhoods will have facilitated access to sustainable transport modes and support local employment opportunities.
The move away from urban sprawl will involve retrofitting the existing urban fabric and the creation of sustainable suburbs and eco-towns. Sustainable cities will be developed through long term urban planning that addresses resistance to climate change and resource scarcity. Cities will move from linear systems to closed loop resource systems for energy, water, food and waste.
Sustainable urban villages are likely to feature walkable neighbourhoods, transit orientated developments, integrated transportation modes, distributed working environments, renewable energy generation, smart grids, food production and nature integrated with the built environment. Outlined below are five attributes that are likely to feature in our sustainable cities of the future :
Bike share schemes
Many European cities have bike share schemes and Australian cities will soon be following suit. Launched in 2007, the Velib scheme in Paris consists of around 20,000 bikes docked at 1,450 stations around city, making it the largest bike share scheme in the world.
To use the system, a subscription is paid per day, week, or year with the first half hour being free of charge to encourage the bikes to remain in constant circulation. The scheme encourages healthy sustainable transport, is cheaper than using the metro and reduces reliance on private fossil fuel driven cars, leading to improved air quality.
The Velib scheme has proved very successful with only a few problems arising, including the tendency for people to use public transport to climb hills whilst leaving their bikes at the bottom of them, leading to surpluses at places like Montmatre.
In early May 2009 the Victorian government committed five million dollars to setting up a similar scheme for Melbourne. Brisbane is further down the track, having issued a call for tender to operate a bike-share scheme.
Green roofs and walls
At present, city and suburb dwellers are somewhat disconnected from nature. Urban and suburban developments prioritise buildings over nature which is often contained and relegated to the periphery of development. Sustainable urban villages will acknowledge people’s fundamental need to connect with nature and the changing seasons by preserving existing ecosystems and encouraging biodiversity. Parks, bushland, foreshore and beaches will be accessible to all and, rather than being considered as a separate entity, nature will become integrated into the fabric of the built environment.
Green roof construction, notably used by the Vikings, is experiencing a revival in European urban design and the concept of a Vertical Garden has been championed by Patrick Blanc. There are several examples of green roofs in Australia including Parliament House and M Central in Sydney. Benefits of integrating green roofs and walls into the building fabric include improved thermal insulation, reduced urban heat island effect, stormwater retention, provision of habitat for biodiversity and improved air quality. They can also provide an attractive visual landscape and recreational space for residents and workers and even function as a space for food production.
Urban food production
Much of our food is grown, processed and packaged a long way from where it’s eaten, resulting in high greenhouse gas emissions associated with food transport and reduced food quality. Food miles, a measure of distance travelled from paddock to plate, can be significantly reduced by producing food in urban areas. As climate change renders some areas unsuitable for food production and transport fossil fuel costs rise, urban food production will become a feature of the cities of the future.
Cubans had to rapidly adapt to shortages of fossil fuel, food and fertiliser after the collapse of the Soviet Union, its major trade partner, in 1990. Faced with starvation, the government introduced state farms and helped to set up community gardens. Residents grew food wherever possible; in planter boxes, on balconies, in private gardens and community allotments. By necessity households and neighbourhoods became more sustainable and it is currently estimated that 40 per cent of Cuban households are involved in urban agriculture with 50 per cent of national food production occurring in urban areas.
Edible produce can be cultivated in the humble backyard veggie patch in the ‘burbs’ or in allotments and community gardens for inner-city residents and high-rise tower dwellers without backyards. Some city dwellers have even taken the initiative, cultivating fruit and vegetables on street verges. Neighbourhoods and public spaces can become both edible landscapes and a visual feast, with passionfruit vines growing along back fences and mulberry bushes planted in public squares or parks.
Food may be produced on a mass scale in cities of the future using hydroponic or aeroponic technology. The University of Columbia has developed a vertical farm concept which involves growing food organically in a high rise tower supplied by energy produced from methane (derived from composting plant material) and irrigated by water recycled from black and grey water sources. Benefits include reduced transport CO2 emissions, year round food production (and biofuel for vehicles), no crop failures due to droughts or floods and no agricultural runoff.
One of the effects of advances in information technology and the arrival of the internet has been the advent of telecommuting. Telecommuting involves working from home using a computer and internet and telephone connection.
Sustainable cities of the future will support a significant proportion of the workforce working regularly outside the confines of the traditional office. This will have ongoing benefits for the environment as it reduces private car use and traffic congestion, thereby reducing greenhouse gas emissions and improving air quality.
A further advantage is the reduction in costs associated with commuting. Flexible working arrangements promote work / life balance as the time spent commuting can be spent with family or undertaking home duties. For a business, telecommuting reduces the need for office equipment and space by decentralising the workforce.
The option to work from home can provide an incentive for staff recruitment and retention. Companies with effective telecommuting policies are more resilient when faced with external disruption, such as severe weather and transport strikes.
Telecommuting also promotes access to work for people with specific difficulties or disabilities.
Working in a distributed work environment can be facilitated through the provision of fast IT connections. Some local planning authorities may also need to alter zoning to permit the co-location of residential and light commercial / industrial activities.
District infrastructure systems will feature in the sustainable suburbs of the future. No longer will resources such as power, water and waste be provided by centralised systems and managed by large distant companies. Instead, district systems will supply energy and water and manage waste, which will be recycled and reused at a neighbourhood scale.
Site-scale infrastructure encourages closed loop systems, where resources are generated or used on site, then reused / recycled. While district systems have many operational efficiencies, they must also be efficiently managed and maintained by professionals.
District water recycling systems are becoming widespread in Australian cities and suburbs. Sydney Olympic Park has an established district water recycling system. Treated wastewater is circulated in a purple pipe for garden irrigation.
Site-based systems where energy is generated and used on-site (e.g. photovoltaics, solar hot water systems) reduce transmission losses. Greenwich Millennium Village in London has a district energy system comprising a cogeneration plant which provides electricity and hot water to homes, commercial and retail businesses for domestic hot water and hydronic heating. An ESCO (energy service company) is contracted to operate the system for thirty-five years.
The BO01 neighbourhood of Malmo aims to be an eco-cyclic city district and has an innovative and integrated site waste recycling system. It comprises three waste systems ; a kerbside recycling scheme, technology that transports waste from rubbish chutes using vacuum suction, and a system where organic waste is chopped up via a kitchen sink disposer, then flushed away to an anaerobic digestor. From here biogas is produced for heating, vehicle fuel and fertiliser.
Danielle McCartney is a Senior Associate and the manager of the Sydney office of Sustainable Built Environments. She has a professional background in Architecture and a Masters in Environmental Design from the University of Cambridge. Danielle’s area of interest and expertise is sustainable masterplanning. She has had experience in developing and implementing sustainability strategies for new mixed-use commmunties and urban regeneration projects in the UK, Europe and Australia. Danielle has also authored Fact Sheets for the Federal Government’s “Your Development” website.
Sustainable Built Environments is an integrated multi-disciplined ESD team with offices in Sydney and Melbourne. SBE’s skills span architecture, engineering, project management and environmental science, enabling the provision of integrated ESD advice on project teams.