IT WILL house a third of a million people in China. It is expected to cost 22 billion dollars. It will take a decade to build. It is the very latest in "eco-cities" that a leading UK-based company is greatly involved in its development.

The aim is for Tianjin to become "an international centre for environmental expertise and green innovation, serving as a model for eco-cities across the developing world".

UK consultancy Mott MacDonald has been awarded a key role on the new flagship sustainable development in northern China for its clients, the Sino-Singapore Tianjin Eco-City administrative committee and global environment facility.

The eco-city is being constructed over a 10-year period as part of an agreement between the governments of China and Singapore. Once completed it is hoped that Tianjin, which will cover about 30 square kilometres (11.5 square miles), will house up to 350,000 people.

The role of global management, engineering and development consultancy Mott MacDonald on the project is to provide technical assistance in the creation of a sustainability strategy for the eco-city.

The assistance encompasses green building, green transport, and industrial and commercial strategies - all underpinned by education options and stakeholder engagement to encourage "low energy" living.

The UK consultancy will also lead on the design of two demonstration projects - a 20,000 square-metre middle school and a 600-apartment residential complex, both of which will be required to demonstrate a 65-per-cent saving in annual energy compared with the benchmark of the previous national standard.

Mott MacDonald will be working with local design teams on the demonstration projects to determine what sustainable design features and improvements can be adopted, along with their relative cost, in order to define the final, cost-effective designs.

Dr Anne Kerr, Mott MacDonald's project director said: "Tianjin will have one of the world's lowest-per-capita carbon footprints. To achieve this, we are applying the latest thinking and the best available technologies, and bringing together different design disciplines in an integrated way to achieve trailblazing performance in sustainable living."

The eco-city is located in northern China in Binhai New Area, a region earmarked for rapid economic growth and well linked to Beijing and other major economic centres.

The aim is for Tianjin to become an international centre for environmental expertise and green innovation, serving as a model for eco-cities across the developing world.

Tianjin's highlights will include innovative public transport and pedestrian-oriented urban design to limit the use of private motorised transport (to fewer than 10 per cent of journeys), a wetland to provide natural treatment for recycled wastewater, and the use of organic waste to produce heat and power, with 60 per cent of the city's waste being recycled.

In addition, management of power and water consumption combined with clean and renewable electricity generation will be used to limit carbon emissions.

Mott MacDonald's project coordinator Jenny Jiang added: "One of the key factors in the development of Tianjin is to find sustainable solutions to deal with the challenges of high-density urban living. The needs of China's huge population and the country's rapid growth require imaginative and sensitive approaches to urban building design.

"The establishment of the eco-city is to explore how to demonstrate low carbon emissions in a brand-new city in order to cope with the issue of global climate change."

The construction of Tianjin's first phase, an eco-business park, has begun.