A discussion on green buildings usually ends up hovering on cost factors involved in adopting these practices and differing opinions come to fore on the issue.
Some believe that green buildings are a costly affair and not everyone can afford them while others think that green buildings rely on not yet proven technologies. But what are green buildings and are they really that costly? “Any building that demands less energy, causes less damage to environment, can conserve water or was made using recycles or energy efficient material should be considered as a green building,” says construction material expert, L.H. Rao.
A green building doesn’t have to be a fancy concept. Any construction can be converted into a green building just by creating simple structures like rain water harvesting pits, using landscape effectively along with employing recycled materials, Dr. Rao observes. Green buildings are energy efficient, resource saving, eco-friendly, healthy and offer comfort to residents.
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Because of the tropical conditions most of our cities receive abundant sunshine and ideally the air conditioning systems should be the biggest power guzzlers in our homes.
“But, because of the faulty positioning of windows and indiscriminate use of curtains, we are forced to keep our lights turned on all the time.
This puts additional pressure on our electricity bill,” he says. If a building is properly planned, even the air conditioning bill doesn’t have to be back breaking, Dr. Rao opines. With enough provision for free movement of air in a house, one can reduce the power bill, he said.
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But apart from ensuring enough air and lighting, a building can also be converted into a green building by using materials that have longer gestation periods and are environmentally friendly.
“The cost of a building in terms of its effect on environment can be reduced by using alternatives like blended cements, geo-polymers, recycled material, fly-ash bricks and substitutes for wood,” he explains.
Traditional cement, known as Ordinary Portland Cement (OPC), consumes a lot of energy. On one hand we use a lot of precious lime stone in the production process, on the other hand due to its chemical composition, it starts disintegrating sooner due to effects like lime leaching.
“These issues are not there in the blended cements like Portland Pozzolana Cement (PPC) and Portland Slag Cement (PSC). Since a portion of raw materials that are used to make PPC and PSC are industrial by-products, the effect on environment is lesser, and due to their chemical composition, these cements become stronger with the passage of time,” he says.
Apart from cements, using material like interlocking blocks, wood substitutes, volcanic tuff, agricultural wastes-bamboos and jute fiber, among others, can reduce the burden on the environment.
Quoting the example of fly-ash, a by-product produced at thermal plants, Dr. Rao explains that using fly-ash bricks and hollow blocks can reduce the bad effects of fly-ash on the environment.
“When fly-ash is dumped into lakes and ponds, the carcinogenic material in the ash seeps into ground water and endangers lives.
But if the same fly-ash is used in cements or in bricks, the bad effects of the ash are locked into the material and this helps in containing the harmful effects,” he explains.
Another step that can be taken is reuse of the material. “Many a times we see that the discarded building material particularly demolished concrete is dumped in to the land fills or discarded mindlessly. Rather than destroying natural rock for making gravel, the discarded building material can be reused in many places like paving roads and other low grade civic constructions,” he adds.