Sat 1 Sep 2007
Downtown in Dongtan and Abu Dhabi
With Gordon Brown planning five new eco towns, Roger Hunt takes a look at two massive schemes leading the way in China and the UAE.Building one-off eco homes or even sustainable villages, although highly laudable, is never going to be the answer. In the UK, the government now has its sights set on eco towns and "is looking to encourage and support local authorities and the private sector to bring forward around five new schemes".
Overseas the eco living concept is being considered on an all together larger scale, with hugely ambitious eco cities being planned in China and the United Arab Emirates. The idea being promoted is that they will be eco showcases for others to learn from.
In August 2005, Arup, the global planning, engineering and design consultancy, was contracted by Shanghai Industrial Investment Corporation to design and master plan what is claimed to be the world's first eco-city, Dongtan, in Shanghai, China. At the time of writing the land transfer agreement is awaited from the Chinese government but construction is expected to start this year.
At three quarters the size of Manhattan and located at the mouth of the Yangtze River on the third largest island in China, Dongtan is situated in an extremely strategic position very close to Shanghai. It will be developed on 8,600 hectares of land and will eventually be a city of three villages that meet. Integrated sustainable urban planning and design will mean energy consumption is low, the underlying premise being to create a development that is as close to achieving carbon neutrality as possible within economic constraints. In buildings this will be achieved by specifying high thermal performance and using energy-efficient equipment and mechanisms to encourage building users to save energy.
The first phase to be developed - with the aim of completion by 2010 in time for the World Expo in Shanghai - is to be the East Village where there will be around 2,500 to 3,000 dwellings accommodating a population of up to 10,000. In addition, the village will contain a marina along with nearly one square kilometre of open spaces and parkland. With subsequent phases the population is projected to grow to 80,000 by 2020 and, as development progresses, to around 500,000 by 2050.
Interestingly, only around 40 per cent of the Dongtan site will be dedicated to urban development. The area is mostly agricultural land adjacent to a huge wetland of global importance so ecologically sensitive design is central to the master plan. Food for the inhabitants of the city will be grown on farmland within the Dongtan site, cultivated using organic methods, with nutrients and soil conditioning employed together with processed city waste. The development of techniques that increase the organic production of vegetable crops will mean that no more farmland will be required than is available within the boundaries of the site.
Making the city sustainable is vital to Dongtan's success. Its compact nature reduces infrastructure costs as well as improving amenity and energy efficiency to public transport systems. All housing will be within seven minutes' walk of public transport and will have easy access to social infrastructure such as hospitals, schools and workplaces.
Phase one of the project will include priority projects such as capturing and purifying water, waste management recycling, reducing landfills that damage the environment and providing electricity, heat and fuel entirely by renewable means. These include a combined heat and power (CHP) plant that runs on biomass in the form of rice husks (the waste product of local rice mills) a wind farm and biogas extracted from the treatment of municipal solid waste and sewage. Electricity will also be generated within buildings, using photovoltaic cells and micro wind turbines.
A key feature of energy management in Dongtan will be the level of information provided to consumers to encourage them to conserve energy, for instance, by means of smart metering and financial incentives.
When it comes to the construction of the buildings, details are somewhat vague but a "combination of traditional and innovative building technologies" will reduce energy requirements by up to 70 per cent. The labour and materials will, where possible, be sourced locally to reduce transport and embodied energy costs related to construction.
As an illustration of the joined-up thinking that appears to be associated with the project, the use of public transport with reduced air and noise pollution will mean that buildings can be naturally ventilated, in turn reducing the demand on energy. Buildings with green roofs will improve insulation and water filtration and provide potential storage for irrigation or waste disposal.
Dongtan will be a city linked by a combination of cycle paths, pedestrian routes and various modes of public transport, including buses and water taxis. Canals, lakes and marinas will permeate the city, providing a variety of recreational and transport opportunities. Visitors will park their cars outside the city and use public transport within.
Hard on the heels of Dongtan comes the Masdar development, a zero-carbon, zero-waste city at the heart of Abu Dhabi in the United Arab Emirates. The new 640-hectare energy, science and technology community of some 50,000 people is scheduled to open in late 2009 and will use the traditional planning principles of a walled city.
The city is an integral part of the Masdar Initiative. This is "the catalyst for fusing research and innovation from the best people in the world from both academia and international corporations" and results from Abu Dhabi's decision to invest in a long-term strategic development programme for alternative energy and sustainable technologies. Masdar's research, production and university facilities will be located within the new city, which will be linked to surrounding communities, as well as the centre of Abu Dhabi and the international airport, by a network of existing road and new rail and public transport routes.
Masterplanned by Foster + Partners, the Masdar development uses the traditional planning principals of a walled city, providing a mixed-use, compact, high-density environment with around 30 per cent of the area devoted to housing.
The city itself will be car-free with the population no more than 200 metres from essential amenities, including shops selling locally produced produce, and transport links which include a personalised rapid transport system. The city's tightly planned, compact nature will encourage walking with the shaded, narrow streets creating a pedestrian-friendly environment in the context of Abu Dhabi's extreme climate.
Dealing with the climate has been a significant design consideration. The city's orientation captures cooling sea breezes from the north while its perimeter protects against the warmer desert winds. Courtyards and wind towers will draw cooling breezes into the narrow streets which will be shaded by photovoltaic collecting canopies designed to filter the harsh sunlight and convert it into electricity. In addition, the relationship of one building to the next will provide shading and result in year-round usable spaces in-between.
In terms of the buildings themselves, construction materials with a high thermal mass will considerably reduce energy requirements while solar collectors on roofs throughout the development will power the city. The perimeter wall is designed to form an intelligent outer shell housing the energy, environmental and recycling services.
With expansion carefully planned, the surrounding land will contain wind and photovoltaic farms, research fields, plantations, recreational areas and sports facilities so that the city will be entirely self-sustaining.
"By attempting the first carbon-neutral city in the world, Masdar is demonstrating its commitment to change the way the world understands energy and sustainable resource utilisation. One day all cities will be built like this," concludes Masdar's chief executive officer, Sultan Al Jaber.
Masdar's energy strategy
Various renewable energies are being considered:
Photovoltaic (PV) technologies:
Large scale use of PVs is planned. A state-of-the-art PV power plant will be constructed outside the city and PVs will be integrated into the majority of the structures within the development and will provide almost half the electricity required. Three types of PVs will be used: monocrystalline silicon, polycrystalline silicon, and thin-film PV to allow innovative, building integrated designs.
Concentrating solar thermal power:
A field of mirrors may be used to concentrate sunlight on to a specific point creating extremely high temperatures. This heat is then used to produce steam as in a conventional power station; the heat and waste heat can also be used directly for thermal purposes.
Wind power:
Large wind turbines are proposed at the south-west and north-east corners of the site, as well as some building-integrated 'urban turbines'.
Municipal solid waste:
The use of advanced recycling, composting and combustion of collected waste can lead to a drastic reduction in land-fill requirements, with recycling and composting offering opportunities for reductions in greenhouse gas emissions.
Ground-source heat pumps (GSHP):
Heat can be exchanged between the hot land surface and the cooler earth below ground using geothermal heat pumps. It is a concept with the potential to reduce electricity consumption for cooling by more than 50 per cent. Piping to accommodate GSHP would be sunk into the spaces alongside the buildings.
First published in Show House Magazine September 2007.
The greatest care has been taken to ensure accuracy but some information contained within this article may have changed since it was first published.
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