Published September 07, 2012

Material with new sheen

The use of glass in buildings here has become prevalent due to its aesthetic and practical qualities

By zeinab yusuf saiwalla

ARCHITECTURE in Singapore is visibly changing, shedding its bulky concrete skin for a clearer and more transparent one. Glass may have been created some 4,000 years ago, but advancements in technology have given the material a new lease of life.

While the use of glass in construction was once limited to grandeur designs, it has become a core structural and design element of many buildings and homes today. More residential apartments and commercial buildings are now wrapped in glass, exuding a modernistic feel compared to those with traditional solid wall structures.

Although previously thought to be one of the most fragile materials - restricted for use in very precise conditions - glass in construction has increased dramatically due to the rapid changes in glass production and technology.

Moreover, as Tong Bin Sin, senior associate director at DP Architects, explains: "Glass in its basic form has an ethereal transparency that lends a sense of visual lightness to architectural designs compared with materials like masonry and metals."

With over a dozen varieties of construction glass available in the market, the functional capability of the material has grown by leaps and bounds. Now, glass can easily be transformed from a brittle and highly reflective material to a sheet that is strong, energy efficient and insulating.

The appeal of glass is crystal-clear, say its backers. It is contemporary, stylish, offers great views and gives a sense of spaciousness - a quality especially meaningful given the current trend of shrinking apartment sizes.

"There is something fascinating about working with glass because it allows us to merge two environments - the external with the internal. It allows the outside in while keeping it out, and captures part of the sky," said Theodore Chan, president of the Singapore Institute of Architects.

For Kelvin Kan, a glass specialist and facade consultant who is also the principal architect of AgFacadesign, designing with glass has become a passion. In a recent project which saw the transformation of 158 Cecil Street's atrium from a "dark and dingy space" to one that is brightly lit and spacious, Mr Kan worked creatively with glass sheets to construct transparent wings along the building's facade, resulting in a " lighted lantern of green from across the street".

For developers, however, the lure of glass lies more in the tangible benefits than the design creativity it offers.

"The use of glass creates a modern and stylish feel for commercial developments. When used in the context of a mall, the level of activity in the mall can be easily seen from the outside, drawing more shoppers into the mall," said Chng Chee Beow, executive director of CEL Development Pte Ltd.

Besides the obvious benefit of glass that comes with its transparent nature, the use of glass has also soared due to its relatively easier maintenance.

The impervious nature of glass makes it less susceptible to environmental stains. Periodic cleaning of the glass keeps a building looking new unlike solid walls which demand regular painting and plastering to conceal cracks, mouldy growth and peeled paint, explained Mr Chan.

Also, a glass building is much faster to build. Glass curtain walls which are bolted to the building can be pre-made, shipped to the site and immediately installed.

Concrete walls, on the other hand, need to be erected floor by floor. This takes almost two-thirds additional construction time.

Furthermore, "the cost of using glass in buildings has been getting more competitive and affordable with the influx of made-in- China products of comparable quality", said Mr Tong.

Figures from International Enterprise Singapore on the glass trade show that $554.7 million worth of construction-worthy glass was imported in Singapore in 2011, up from $257.9 million in 2008.

All the glass used in Singapore is imported from Malaysia, Indonesia, China, Europe and the United States.

Before glass became the material of choice, buildings were usually built with solid walls and architects had to take into careful consideration the building's natural ventilating system. This meant that buildings could not have walls that were too thick as that would result in overheating of the premises, especially in a tropical country like Singapore.

However, with glass that can now be manufactured in varying degrees of emissivity, enabling greater solar control of light and heat, such problems are easily overcome, said Gan Geok Chua, executive director at Singapore Safety Glass Pte Ltd.

Today, almost all new constructions incorporate a large amount of glass either in its interior or exterior design. And old buildings, too, are given a new look with a sparkling and shiny glass facade.

Most of the glass used in building exteriors here have surface coatings applied through physical and chemical processes to produce glass with improved thermal insulation.

Developers have the choice of using monolithic or laminated sheets of glass with different emissivity coatings. For example, the glass used in the iconic Marina Bay Sands is of a triple silver low emissivity quality so as to allow 63 per cent visible light through the glass while keeping 72 per cent of the heat out, explained Mr Gan.

Higher-end buildings typically make use of double-glazed laminated glass owing to its added safety and higher acoustic performance.

However, despite the exquisite quality, technological improvements and competitive prices of glass, the uptake and use of glass in architecture here was relatively slow compared to the West.

In the West, where most of the world's iconic glass structures can be found - Fansworth House by German architect Mies van der Rohe, Glass House by Philip Johnson, an American; and the glass box museum by Swiss architect Peter Zumthor - the use of glass gained popularity in the 1950s when the Modernist movement took the lead in design and architecture.

According to Jeffrey Chan, assistant professor at the National University of Singapore's architecture department, "early vernacular works of architecture in Singapore steered away from the use of glass, even when it was readily available, because of climatic reasons".

"The later emergence of the glass- house trend must have in part been the result of the availability of air-conditioning technology rather than critically thinking about the logic of building in a tropical climate," he added.

Furthermore, by the 1990s, glass buildings became synonymous with sophistication and was used as a way of communicating progress.

As Mr Theodore Chan explained: "We started getting wealthier about 30 years back and at that time glass towers had somewhat become symbols of prosperity, so naturally architecture here evolved to reflect that."

However, for all the benefits and positive symbolism of glass, manufacturers and architects alike stress the importance of precision and caution when using the material.

"Glass behaves almost totally elastically and exhibits no reserves of plasticity; the maximum stress that a certain glass can accommodate is determined by local stress peaks which arise at flaws, chipped edges or at the tip of a crack," said Pang Tee Lian, general manager of Seiko Architectural Systems.

This quality reduces the strength of glass and hence demands careful consideration of mechanical properties when designing with it, he added.

Also, given the fact that a clear glass building will collect more light and heat, care must be taken to ensure that buildings are well designed to minimise over- use of cooling devices.

"Air-conditioning is a modern-day convenience to cool spaces and should not be made a justification for the unsustainable use of glass in buildings, as occasionally happens," said Mr Tan.