Opting for energy-efficient building glass

Glass-fronted buildings have nowadays become the new norm in cities in Bangladesh. Almost all corporate headquarters, luxury hotels, hospitals, and shopping malls in all big cities, particularly Dhaka, have adopted this new architectural style, as it represents progress and sophistication. But these glass buildings absorb an absurd amount of energy.

Bangladesh already suffers from frequent power outages due to rising electricity demands. These buildings, with their gleaming exteriors, only worsen the situation with demands for even more power. Experts recommend designing these buildings intelligently, as they are currently incompatible with the country's energy situation. It is time for starting use of high reflective glass or photovoltaic glass, as it will make the buildings more energy efficient.

The glass facades have become an icon of modernity, creating an international look that appeals to most clients. But in a country like Bangladesh, where the temperature often goes over 35°C, this style of architecture poses a great risk. The glass allows sunlight to enter the building, which raises the indoor temperature, leading to complete dependence on air conditioners. These glass-covered buildings use up to 30-40 per cent more electricity than traditional buildings. The issue is even more apparent in the summer seasons when the energy consumption of the country is at an all-time high with the air conditioning of such buildings accounting for the major portion of it.

Bangladesh has made remarkable progress in generating electricity, exceeding 25,000 megawatts. Yet it is plagued by frequent load shedding, mainly caused by inefficient energy use. Load shedding --- most frequent during heat waves ---affects households, industries and other essential services such as hospitals. On the other hand, Bangladesh's dependence on imported fuel is increasing, affecting the country's goal of reducing the same and replacing it with renewable energy.

The integration of high reflective glass in buildings could ease the problem. Coated with metallic oxide layers, high reflective glasses prevent a huge portion of solar radiation from entering the building, reducing air-conditioner usage and electricity consumption by 20 to 40 per cent. Neglecting these advantages, developers opt for cheaper, ordinary float glass. But the difference in initial cost is negligible when compared to the potential reduction of energy cost.

On the other hand, photovoltaic glass goes a step further and generates electricity with the solar cells integrated into it. It transforms some of the sunlight into electricity, allowing buildings to compensate for some of their electricity consumption. Besides several western nations, countries like Singapore, Japan, South Korea, Malaysia, and the United Arab Emirates are also using this technology in their skyscrapers. In a country like Bangladesh, where energy demands are higher than the production capacity, integrating high reflective and photovoltaic glass could be revolutionary with buildings turned into vertical power plants. Several obstacles keep this from becoming a reality. Many developers are still unaware of both the energy implications of glass-coated buildings and the improved alternatives to them. Furthermore, the country's building code currently does not require energy efficiency.

Overcoming these obstacles requires raising awareness and revising the Bangladesh National Building Code. Awareness campaigns have to be conducted to educate both developers, property owners and the general public on the negative impacts of glass-coated buildings and the merits of their alternatives. The National Building Code should include provisions for buildings to be energy efficient while developers and architects should be trained to start incorporating high reflective glass and photovoltaic glass in their designs.

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