Windows: less is more

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Shengkai Chiu
Jones Lang LaSalle, SE Asia

On one recent occasion when I returned to our Singapore corporate office on a Sunday afternoon to work (I hope my boss is reading this) and to my surprise, I didn’t feel like a Peking Duck sitting in a baking oven even though the central air-conditioning wasn’t on.

Our office is situated in a 16-year-old skyscraper, whose designers obviously had figured out how to create a good insulated envelope. But when I took a closer look, I saw that the façade uses tinted single-glazing, a glass type with one of the worst insulation values in the market (probably the only economically viable glass type back then). Then how in the world did this building manage to keep its cool?

The secret lies in its window-to-wall ratio (WWR). The smaller the ratio, the less direct sunlight / heat energy can penetrate through the glazed surfaces. Not rocket science! However, the popular architecture “fad” nowadays, is to take concrete / brick walls (which act as a shield to sun and heat energy) totally out of the envelope equation and build curtain-wall glass towers. Some of these tried to minimize the heat-gaining effect by specifying high-insulation glasses. But do you know the best high-insulation glasses have similar insulation value as 1~2-inches thick cardboard? I can already see the utility bills mounting up from running jumbo-sized chillers to cool these big cardboard boxes!

Closely resembling structures, to these glass towers, were built as early as the 13th century – green houses. I can understand applying this concept in buildings located in high-latitude countries to reduce heating energy bills, but this is not exactly an energy-conscious design for a building in a tropical climate country like Singapore… unless the intent is to make people feel like a Peking Duck on a Sunday afternoon? 

Could the architects have done a better job designing environmentally friendly and sensible commercial buildings, or are there other forces in play that force them to design giant glass towers in tropical countries? I know one explanation why inch-thick glasses replace foot-thick concrete walls in Singapore, where real estate prices like gold. But if you place high value on sustainable (financial & environmental) long-term operation, do pose this question to your architect. In the end, I hope the consideration for the environment and overall life-cycle operation will prevail.

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