 |
 |
You are here
Cover Story | GLASS & GLAZING
Glass is Green(?)
There’s a raging debate on if and when glass is the appropriate material to use in buildings
Architect Balbir Verma (balbirv@gmail.com) has appealed that the senseless use of glass must end. Verma, who is past president of the Indian Institute of Architects and UIA council member, believes that in the quest for aesthetics, building designers are glossing over the fact that glass is the most inefficient of materials where heat, noise and dust are concerned. He says that the wrong use of glass in facades makes a building expensive and uncomfortable, permanently.
The use of glass in construction began in earnest in the 1990s, when it graduated from a mere aesthetic material to a structural substance by aiding inflow of spaces, establishing transparency in architecture, and making nature merge into design. Fascination for the glass structure started with the information technology boom, as the IT industry sought working spaces that symbolised communication and openness. Soon residential skyscrapers, shopping malls, airports, all started seeking the freedom provided by glass to fulfill their commercial, lifestyle or security objectives.
But the initial usage of glass in buildings soon led to overdose, or “senseless use” as Verma prefers to call it. Recently a Chennai-based IT firm on Rajiv Gandhi Salai, with glass facades facing east-west, sought correction to the inflow of the Sun’s rays as load-shedding was making it tough for employees to work, and the diesel generator was adding to the running expense. Obviously the owner or the designer had not considered this scenario while conceptualising the building. And there are many more such instances of IT firms, housed in commercial complexes with glass envelopes, approaching architects to correct the design because excessive transparency was resulting in greater absorption of heat and radiation.
 |
 |
| Balbir Verma | Dhruv Futnani |
Anupama Mohanram, co-founder of Chennai-based architectural firm Green Evolution Architectural Consultancy, says that lack of fewer openable windows makes it a bigger challenge to recommend alternatives in some glass facades. “The problem with glass structure is that it absorbs and radiates heat. To prevent sunlight from glaring on the face or the computer system, blinds are used, but in the process the lights inside have to be switched on.” Mohanram is a LEED-accredited professional and a certified GRIHA (Green Rating for Integrated Habitat Assessment) trainer and evaluator.
State of the Industry“SGGI is the undisputed leader of the Indian glass industry, followed by AIS and Gujarat Guardian at the number two and three spots, respectively,” according to the SH Toppers 2010 report published in the March-April 2011 issue of Sourcing Hardware magazine. The report says that three brands – Saint-Gobain, AIS and ModiGuard – dominate the industry, but in terms of muscle the first two toppers are way ahead and will continue to call the shots in the foreseeable future. We reached this conclusion after studying industry trends over a four year period, from 2006-07 to 2009-2010. Glass, which is today the designer’s first choice when it comes to materials, had its finest hour in 2008-09 when the collective sales of the SH Toppers grew 23%. Even the previous year saw near equal growth. But in 2009-10 the market for glass tanked, with collective growth registering a negative 1.5%! The growth of this sector would have been much higher had Gujarat Guardian (ModiGuard) and Gujarat Borosil not been a drag. On the whole the `4,000-crore glass industry has grown by over 13% during the past four years, and due to lacklustre performance last year, its growth is likely to be a modest 5.5% through 2010-11. Three brands – Saint Gobain, AIS and ModiGuard – dominate the industry. But a host of processors have recently diversified backward by setting up float glass plants of their own. Yet, the leaders remain unperturbed. “The key differentiator in this industry is complex processing using laminated or IGU, quality and timely delivery,” says a key executive from AIS Glass Solutions. And, indicating that by leveraging infrastructure and using cutting edge technology, companies like his will always dominate, he adds, “With all the necessary infrastructure and capacities in place, it is now time for AIS Glass Solutions to de-bottle the manufacturing inefficiencies and focus more on timely delivery.” In the same vein, Vinay Kumar Modi of Gujarat Guardian, the company that owns the ModiGuard brand, asserts, “We are continuing our focus on customer service and improving operational efficiencies. With a strong distribution network and a powerful brand, our company is well placed to meet any present and future competition.” The yawning gap between the first three toppers in glass and the other two lends credence to the possibility that new, more agile players could join this elite group soon. True to the words of Sezal Glass CMD Amrrut Gada, which hint at continued aggression, the company announced that it would invest `500 crore to expand its glass processing business. This is after Sezal sold off its float glass facility to SGGI. Gada said that Sezal is aiming to become a complete value-added glass manufacturer. “If we consider aspects like climate, safety and aesthetics, we would see that the demand for value-added glass is fast increasing in the country. With the present expansion in place, we aim to grab 15% market share of this business in a span of 3-5 years.” AIS has 2 float glass units with a combined capacity of 1,200 tonnes/day, and three architectural glass processing plants. Very recently it has diversified into the windows systems business by setting up an aluminium and uPVC window manufacturing unit near Delhi. Market leader SGGI’s World Glass Complex at Sriperumbudur near Chennai houses 2 float glass plants, a solar control reflective glass unit, a mirror processing line, and a Magnetron Coater facility to manufacture high-performance energy-efficient glass. The company recently purchased Sezal Glass’ plant in Gujarat, which had a capacity to produce 550 tonnes of float glass/day, for Rs.686 crore. SGGI is establishing another facility in Bhiwadi, Rajasthan. “This facility will have a capacity to manufacture over 3 lakh tonnes a year.” Being set up with an investment of `1,000 crore, the plant will be operational in 2012 and will be one of the world’s largest float glass plants. Once this plant goes on line, SGGI will have a pan-India footprint. |
According to her, with GRIHA compliance now mandatory for buildings of central government and public service undertakings, firms are getting cautious about the percentage of glass used. “Glass is not the best material for a place like Chennai. And if buildings are not designed with high performance glass that helps in controlling the solar thermal heating of interiors, making correction is a big task. All windows should orient towards the north-south side and clear glass should be avoided, and as per GRIHA, the usage of glass in openings should be restricted to 60% of the total wall area.”
Buildings are the largest consumers of energy, something that is fast becoming the worst crime in the world. With the carbon economy gaining ground, corporates will have to start taking a serious look at how climate-sensitive their offices are, and energy optimisation will play a major role in reducing their carbon footprint. Also, low carbon emissions will soon become one of the criteria that global investors look at when they want to put their money. Glass architecture is prominent in developed economies not because they deal with colder climates, but because they are using this material more intelligently. “Glass, if used correctly, can actually minimise energy consumption while maximising the use of daylight and offering a host of other benefits,” says Verma.
Since there is no escaping the fact that glass is now an integral part of the building facade in modern architecture, its use calls for careful consideration of a number of parameters, both of the material as well of the surroundings. Dhruv K Futnani(green@dhruvfutnani.com), a sustainability consultant, believes that the decision to use glass and its selection should depend on the architectural character, which would further depend on the colour, reflectivity and transparency required. “An architect is an active member in the green building process, and his choice of glass has a major impact on the energy-consumption and indoor environment of the building,” he says.
Futnani explains that glazing, which is a vital element in the building envelope system, acts like the skin of the structure by becoming a barrier to prevent heat transfer from outside (in hot climate) and vice versa in colder climates. “Since the U value of glass is less than that of a solid wall or concrete roof slab, its correct use becomes all the more critical.”
Any material used in an intelligent manner that results in energy saving and a better indoor environment can be considered green. Today energy modelling, solar studies and daylight analysis are extensively used to select the most appropriate glass for a building. These simulations calculate the properties that the glazing would need, to balance U value (to reduce heat transfer and save energy due to air-conditioning) and visible light transmittance (which allows daylight and saves on artificial light and improves productivity of occupants). The form of the building, the shading provided, glazing extent, and climate of the site, all have an impact on glazing selection. Hence, the optimal use of glass is more critical than its properties.
No wonder responsible building professionals in India have started calling for a more intelligent use of glass. As if on cue, the Confederation of Construction Products & Services (CCPS) has recently released a set of guidelines for the selection and use of glass in buildings, which it wants to be made mandatory (See page 83 CCPS Issues Guidelines for Glass Use ). The Federation of Safety Glass (FOSG) on its part is developing a training programme for glass installers and professional, which when finalised, will be offered to the Industrial Training Institutes for inclusion in their curriculum. The Saint-Gobain Glass Academy, set up byIndia’s largest glass maker, is another indication of how critical education about glass, or lack thereof, is to theconstruction sector.
