Over the past year and a half, a striking building has been taking shape on the campus of National Cheng Kung University in the southern city of Tainan.
This pathbreaking structure, the Y.S. Sun Green Building Research Center, named in honor of the former ROC premier who died in 2006, is also known as the Magic School of Green Technology. Its exterior has several nautical touches, including a ship’s prow, and railings like those on a cruise liner. However, its uniqueness goes beyond outward appearance.
One of the functions of the MSGT, which was inaugurated Jan. 12, is to help people understand why sustainable architecture is important, and how certain design and construction methods can lessen a building’s impact on the environment.
With four stories and 4,799 square meters of floor space, the school is expected to consume just 43 kilowatt hours of electricity per square meter of floor per year—65 percent less than similar office buildings in the ROC.
The design is so remarkable that the building and its principal designer, NCKU architecture professor Lin Hsien-te, were featured in a Discovery Channel documentary while it was still under construction.
“Natural ventilation is the key issue for this building,” architect Joe Shih explained when asked how such large energy savings are possible. Throughout the project, Shih has endeavored to reconcile Lin’s sustainability targets with the properties of conventional building materials, budgetary limits, NCKU’s requirements, local building codes and his own “ways of dealing with light and space.”
“Extensive computer modeling and experimentation were conducted to find the best natural ways to increase indoor ventilation,” Shih said.
The school’s three solar chimneys are a result of these efforts. Each consists of a large pane of glass behind which black concrete absorbs the sun’s heat; there are no moving parts. Convection draws warm air up from inside the building, ensuring constant circulation and reducing air conditioning by 30 percent.
“The green roof, healthy building materials and high efficiency lighting all play important roles,” added Shih.
About half of the funding for the MSGT came in the form of a NT$100 million (US$3.45 million) donation from NCKU alumni Bruce Cheng, chairman of Delta Electronics Inc.
Delta, the world’s largest provider of switching power supplies and DC brushless fans, has long been at the forefront of energy-efficient architecture.
In 2006, Delta’s office-factory complex in the Southern Taiwan Science Park was given a gold rating under the green building certification system of the Ministry of the Interior’s Architecture and Building Research Institute. Later refinements led to that rating being upgraded to diamond, the highest possible.
By the end of 2009, just 16 buildings in Taiwan had achieved diamond status.
The MSGT has already been given ABRI’s diamond rating. Later this year, it is expected to earn a platinum award—also the highest possible—from the Leadership in Energy and Environmental Design certification system of the U.S. Green Building Council.
Like the Delta building, the MSGT has a rainwater catchment system that harvests rainwater to flush toilets and water lawns.
Water conservation is important in Taiwan because per capita rainfall is just one-eighth of the world average.
And like many other green buildings, the school has a set of photovoltaic cells that transform sunlight into electricity.
The angle of this array, which is shaped like a leaf and decorated with a huge model ladybug, can be adjusted so it more directly faces the sun and thus produces more electricity. A ship’s wheel is rotated by hand to position the solar cells.
The main entrance sports a three-layer shade to keep out strong sunlight.The tallest part of the MSGT is a frame holding 14 small wind turbines that generate electricity whenever wind speed exceeds two meters per second (about four knots). Combined, wind and sunshine are expected to produce about 5 percent of the electricity used by the building.
While the building is not self-sufficient in either water or power, it does have several features that cut energy and water consumption.
Small windows minimize heat gain from the sun. The roof garden has an insulating effect that cuts the need for air conditioning in summer. Even if outdoor temperatures rise by 7 to 10 degrees Celsius, temperatures within the school will not change by more than 3 C.
Low-maintenance species such as snake grass and lantana cover about half of the school’s roof. Even though these plants are drought-resistant, the garden has been equipped with a watering system because southern Taiwan’s winters are characterized by dry spells that often last six weeks.
The watering system is activated by the absence of moisture; it does not come on unless the plants are perilously dry.
Rather than conventional soil, plants grow in a mix of pea-sized ceramic pellets and soil. The pellets were made by firing reservoir sludge, a raw material Taiwan has had in abundance since 2009’s Typhoon Morakot swept vast amounts of rock and dirt into bodies of water throughout the south.
Like soil, the pellets absorb water and thus reduce runoff from rain and watering. However, because they weigh considerably less than soil, their use in roof gardens is less likely to stress a building.
Reservoir sludge was also utilized for partition walls inside the MSGT.
Other recycled materials used include corncobs for the carpet in the 200-seat lecture theater and discarded plastic bottles for the theater’s curtains.
China Steel Corp. donated slag, a byproduct of the smelting process. Portland cement mixed with slag is 40 percent stronger than conventional concrete. And because less cement is used, utilizing slag cut carbon emissions during the construction phase by one-tenth.
Shih pointed out that the use of concrete is actually a compromise. “Steel is easier to recycle and reuse than concrete, but in Taiwan the cost is much higher.”
Recycling the fabric of disused structures is especially important in Taiwan, where buildings stand for an average of just 35 years, far less than in other industrialized countries. However, thanks in part to its slag-strengthened concrete walls, the Magic School is predicted to last for at least a century, making it a worthy addition to a city famous for ancient temples and Japanese colonial-era edifices.
