Buildings that save
Shopping malls, hospitals, libraries, townships, even cafes, are in an all-out race to be green.
CLIMATE change is a threat that must be tackled globally, especially when considering that it is often those who are least responsible for the greenhouse gas emissions that cause this phenomenon who are most likely to suffer the worst consequences. Further to this, it is the way we use energy in our homes and buildings – by definition locally – that offers the best and most cost-effective chance to mitigate the worst effects of climate change.”
Tony Arnel, chairman of the World Green Building Council (WorldGBC), wrote those timely words in his foreword to the body’s recently released 2010 report. As we do our best to reduce our carbon footprint by driving less, recycling, watching the food we eat, and other daily workable routines, we often forget that the walls that contain us, whether in our homes or offices, also have the potential to make ours a greener world. It is not just a matter of saving energy in our buildings, but also the very materials used to construct these buildings that could possibly be contributing to climate change.
At the Build Eco Expo (BEX) Asia 2010 last month in Singapore, organised by Reed Exhibitions and the Singapore Institute Of Architects, engineers, architects, builders, property developers, environmentalists and government representatives gathered to exchange ideas, build networks, discuss strategies and basically look at how sustainable construction can be taken to the next level. The mood was generally positive that more can and will be done to build green.
Interest in sustainable construction is growing as more and more in the industry see the long-term benefits of building green. The initial costs of construction may be a little higher than normal but with payback periods that can be anything from three to five years, coupled with the fact that a healthier working environment would increase employees’ work efficiency, the long-term benefits of building green are certainly attractive.
In Malaysia, there is a valid reason to shrink the carbon footprint of the construction sector – buildings rank the highest in carbon emissions at 41%, compared to industries (31%) and transportation (28%). In a timely move, the Malaysian construction industry last year launched the Green Building Index to certify structures that are kinder to the environment. And recently, Works Minister Datuk Shaziman Abu Mansor announced that a joint council will be set up by mid-2011 to coordinate green building efforts. The move is to have both the private and public sectors adopt a single rating system.
In Putrajaya, we already have a couple of “showcase” low-energy and zero-energy buildings that are testament to the workability of sustainable construction. Meanwhile, the Universiti Kebangsaan Malaysia Medical Centre is close to becoming the country’s first green hospital, with the installation of 1,750 evacuated tube solar collectors for its solar water-heating system.
In Malaysia, one notable green building is that which houses the Energy, Green Technology And Water Ministry in Putrajaya. Energy engineer Gregers Reimann of IEN Consultants described it as a showpiece for energy efficiency. The energy consumption of the building is half that of surrounding buildings that were built at the same time.
“The construction cost of the building was only 5% more but there is energy savings of 50%. And the payback time is five years,” said Reimann.
Meanwhile, the Pusat Tenaga Malaysia building in Bandar Baru Bangi, Selangor, was designed to be a zero-energy building. For this, Reimann and his team had to push the envelope in every aspect. Vending machines were not allowed as each one can consume as much energy as an entire household.
“We also tried out things that had never been tried before,” said Reimann. “One of those things was what we called a river roof.”
Quite simply, it meant using the roof of the building as a cooling tower. The chiller runs only at night and the cooling is stored in the concrete floor slabs by running cold water pipes embedded in the slabs. At night, the water normally sent to the cooling tower is trickled over two solar photovoltaic roofs and collected again for another cycle. These measures keep the water bill to only RM50 a month.
Although various problems cropped up that affected the chiller efficiency, the system meant that no cooling tower was needed, the solar panels replaced the normal roof, the running water cleans the solar panels while the roof also traps rainwater. Reimann said they are still working on improving the system so that the building will achieve zero-energy usage, as initially intended.
During his presentation at the BEX conference, Reimann pointed out the conflict between energysaving and energy subsidies. “A lot of countries in South-East Asia have policies encouraging energy wastage, because energy is heavily subsidised. We all know if you make something cheap, people won’t care to save because they don’t see it on their bills,” he explained later.
He cited the case of Juneau, Alaska, where an avalanche crippled power lines to the city in 2008. Diesel generators were used for months until the national grid was re-established. Because electricity from the diesel generators was three to four times more expensive, energy consumption in Anchorage dropped by 35% during that period.
He said countries have taken various innovative steps to reduce energy consumption.
“Denmark, for example, introduced a small tax on electricity usage, amounting to RM10 per year per capita, which is hardly noticeable to consumers. The money goes to an independent task force whose only mission is (to look for ways) to save electricity in the country. When the task force’s work was evaluated five years later, it was found that for every RM10 collected from a consumer, the consumer received RM100 back in savings.”
The Eafit University is the first ‘green building’ in Colombia, with plants being part of its facade and a system that collects and reuses rain water, among other environmentoriented applications.
Soaring carbon: Buildings are the largest carbon emitters, releasing more heat-trapping gases than even the transportation sector.
Double duty: At the Pusat Tenaga Malaysia building in Bandar Baru Bangi, Selangor, solar cells provide shade for parked cars and generate energy at the same time.