Low carbon districts: Mitigating the urban heat island with green roof infrastructure
All cities are inherently evolutionary, always transforming and never ‘completed’. Planners have now arted to think about cities as complex biological and natural systems that are analogous to self-sufficient living organisms. Tomorrow’s urban precincts will have to generate at least half of their power themselves, cally and on-site. This willnot be possible without zero-energy and plus-energy buildings. These are already state-of-the-art, and the next stage, with the city district itself acting as a ‘power plant’, is now coming. Precincts that generate all the power they need on their own through decentralized systems for newable energy (using solar PV, biomass, micro wind turbines or geothermal technology) will make city planners’ age-old dreams of inexhaustible clean energy come true. The secure provision of renewable energy and green urban transformation is fast becoming a reality for our society and a major planning focus around the globe. However, realizing this dream requires the input of policy makers, power suppliers, researchers, architects and planners, and citizens alike.
The world continues to urbanize. Today we find shrinking, undynamic and insufficiently developed urban precincts with limited investment and obsolete infrastructure alongside fast-growing, dynamically changing precincts. We need innovative and comprehensive strategies that enable us to more effectively manage the coming demographic and structural changes (Lehmann and Crocker, 2012).
But is the city as we know it today sustainable? Integrated urban development with a focus on energy, water and the urban microclimate will have to assume a lead role and policy makers will have to engage with it in order to drastically reduce our cities’ consumption of energy, water and resources (ICLEI, 2007). The ‘low-carbon precinct’ concept must be developed further into that of a plus-energy city district that is compact, mixed-use and well-connected to public transport. A large portion of each district (minimum 30–40 per cent of the area) should be dedicated to public green space to maximize open space while allowing for higher densities. This approach will give cities new functions and fields of action that will be instrumental in creating the so-called low-carbon city. The challenges resulting from this are part of what I call the post-industrial condition of waterfront spaces, where dock and working harbour functions have moved away to allow for a new type of inner-city public waterfront. Barangaroo in Sydney is such a new precinct; it will be introduced later in this chapter.
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