Energy use will also shape our cities. Urban house types such as terraces and flats have fewer heat loss walls and are more likely to be sheltered by surrounding buildings. They use less materials and embodied energy and make use of existing infrastructure.
Combined heat and power systems ( CHP’s) are more viable in dense urban areas so that neighbourhoods can have their own power station, producing environmentally friendly, cheap heat and power. This could also be linked to a waste incinerator, as seen in Sheffield.Urban Recycling At present most UK recycling takes place through public recycling points. This should be extended to municipal segregated collection as in Milton Keynes. This again will be more efficient in dense housing areas where there is sufficient demand to support viable recycling systems. Cities are already great recycling systems as Jane Jacobs suggested when she envisaged a future where we will ‘mine’ urban waste for raw materials.
In addition to conventional recycling this includes charity shops, second hand furniture stores, scrap yards and small businesses which re-use urban waste. This is a rich vein of economic activity which could revitalise urban economies.Water Saving Water use is a classic linear system. Its purification and transport consumes large amounts of energy as does its treatment and disposal.
Urban areas should use porous surfaces and water from roofs to reduce run-off and to maintain water tables. Grey water recycling could use water from baths and sinks for toilet flushing whilst measures within buildings should reduce consumption.Green Space The most sustainable urban areas are not necessarily those with the most open space. This is good for wildlife but not for pedestrians forced to pass deserted areas at night or for councils responsible for maintenance. Open space can reduce densities and the viability of other systems for local sustainability. Urban areas should nevertheless maximise wildlife as in Richard Register’s vision of Eco-city, where the city is a contributor to biodiversity. We can achieve this through street trees, parks, squares, window boxes, courtyards, private gardens and roof gardens.
Much of this can be put to productive use for food growing.These factors have the potential to significantly reduce the environmental impact of urban development. This not science fiction but is existing practical technology. This is not to say that sustainable urban development will be easy. Many of the principles run counter to current practice and compulsory competitive tendering of waste collection and bus deregulation have made the task harder. Current legislation could however form an agenda for a eco- sustainable future in which cities play a central role, for eg, by 2015 all new developments should be energy/ water self- sufficient.References1. Herbert Giradets Mobilisation – Civilisation, Resurgence 167 p6-9.
2. Robert and Brenda Vale – Green Architecture, Thames & Hudson 1991 3. Manchester 2020 – A Sustainable City Region Project, TCPA, CER 1995. 4. See 2 5.
From Francis Tibbalds – 10 Commandments of Urban Design. 6. Jane Jacobs – The Economy of Cities. Richard Register – From Cities To EcoCities, North Atlantic Books, 1994