Progress, problems in city's green building

SHANGHAI needs more energy-efficient buildings and a new data platform will help building operators reduce usage. Meanwhile, there's a lot of money to be made in retrofitting energy-guzzling buildings. Fu Chenghao and Zha Minjie report for Earth Day.

While "green" buildings are designed to use minimal energy, actual consumption frequently doubles expectations and in some cases may be five times greater.

That is the discouraging conclusion of an architectural practice that studied cases in the UK, comparing expected and actual energy use. The reasons for the gap are more computers and electrical equipment, unplanned cafes and restaurants, longer-than-expected opening hours, and most importantly, building management.

That's probably true where construction of really energy-saving buildings is far from the norm, since it's generally considered too expensive.

"Buildings have people in them and they do many unexpected things that are often overlooked," according to Judith Kimpian, director of sustainable architecture and research at Aedas, which has led the development of an online platform to close the gap between expected and achieved energy consumption.

Reporting and studying energy use data regularly is essential to platform function.

The system called CarbonBuzz allows participants to benchmark their buildings's carbon emissions anonymously, manage risks and share lessons learned by uploading consumption data. And that's free.

"CarbonBuzz gives benchmarks so you can compare yourself against others without revealing yourself," Kimpian says.

For example, a hotel developer might ask its designer to target a certain level of energy efficiency at the very beginning of the project by consulting data from similar projects on CarbonBuzz.

In the UK on average 15-20 percent of energy reductions can be made by simple interventions, she says.

This could mean a lot for China, where buildings account for more than 1.7 billion tons of carbon dioxide emissions, 21 percent of which comes from public buildings, according to Aedas.

This means that a conservative percentage reduction in energy bills could amount to around 20 billion yuan (US$3.17 billion) savings annually for China, it estimates.

Aedas is seeking to bring CarbonBuzz to China by building a Chinese stakeholder group to include local developers and landlords, contractors, government bodies and academic institutions.

She says there are huge challenges to change the industry mindset so education is important at this stage, but adds that some Shanghai stakeholders have expressed their interest in CarbonBuzz.

Long way to go

But the big picture is that green building and the concept of green building, though discussed for a long time, is still far beyond the drawing board stage - at least as far as the public is concerned.

The Shanghai Construction and Transport Commission has approved the green building evaluation standard, which has been applied to ongoing construction and the public and residential buildings in use citywide since March this year.

The standard covers details about energy generation, recycling and use of recyclable material and rooftop greenery, among other elements.

For example, the standard emphases the use of solar energy and ground source heat, which was showcased widely in the 2010 World Expo Shanghai. It also sets requirements on energy consumption - the volume of hot water produced by energy saving should reach more than 10 percent of the hot water supply in a building; the electricity generated by solar or wind power should be more than 2 percent.

In public buildings 50-60 percent of energy consumption comes from air-conditioning and heating, while 20-30 percent comes from illumination, according to construction authorities.