"Even now, we are seeing young people going to companies saying, ‘Yes I'll come to work for you, but I want to bring my own tablets to use', so we can change buildings to adjust to people's habits and save costs and energies," Twinn says.

He says another possibility is replacing conventional lights with LEDs and also task lights that allow users to select the optimal level of brightness. "If they're looking at paper, they may want a higher level of brightness, but if they want to look at a screen, they may prefer lower levels," he says.

However, Twinn says maintaining standards and quality is a challenge in implementing these energy-efficient building technologies in Chinese eco-cities.

He says this is because the engineering consultants, architects, engineers, developers, contractors and other parties in the process all have different visions and responsibilities, but in Western countries engineering consultants like Arup would typically be contracted to see a plan through to its finish.

Zhang Xuezhou, vice-president of China Real Estate Chamber of Commerce, also admits that there are challenges in implementation. "In China, many factors including the change of leadership, the relocation of rural people, and land disputes, may all affect implementation of plans," Zhang says.

Another challenge, Twinn says, is the lack of a set of flexible eco-city guidelines that allows local governments to apply innovation in their own ways.

China's eco-city guidelines have rules about the percentage of plantation required in a built area.

"At the moment you see flat areas of vegetation covering a car park in a lot of Chinese cities. But the benefits could also be realized if you have vegetation on building roofs, which means the built area can be more compact," he says.

To enable this change, the guidelines should change its wording to, say, "vegetation equivalent", so that local innovation is encouraged, Twinn says.

Meanwhile, China's growing consumption of energy resulting from urbanization has created a good environment for many foreign companies to commercialize environmentally friendly technologies.

British company Green Biologics, which has developed innovative bio-based normal butanol (or biobutanol) production technology, says that working with Chinese biobutanol plants has helped to validate its technology, which is now being rolled out to other markets around the world, says chief technical officer Tim Davies.

Davies says that Green Biologics' goal is to establish biobutanol plants of its own in different markets over the next two to five years, but demonstrating the company's technology with its partners in China is a key step to attract investors for these plants.

China had already built a number of biobutanol plants between 2005 and 2010 as a result of the country's efforts to invest in renewable energy sources. Therefore licensing Green Biologics' technology to Chinese plants seemed like a good opportunity to validate them, Davies says.

"A number of Chinese companies have built biobutanol production facilities to use corn starch as a feedstock, but they were not able to operate these plants commercially because corn prices were too high," Davies says.

"They couldn't switch to other feedstock because they didn't have the technology, but Green Biologics had technology in advanced bacterial strains, so we could help make their production commercially viable," Davies says.