The need to built energy-efficient buildings that suit the local climate
Edifices in Bhutan are built to Indian specifications, unsuited to cold climatic conditions
With hot water pipes running under cement floor, transparent sheet roofing, insulated walls and double glazed window glasses, the four-storied energy building in the economic affairs ministry complex, engineers say, is an energy-efficient building.
Facing south, the orientation of the building was to draw in more sunlight, so lesser energy could be used for lighting purposes and to warm the rooms in winter.
With office buildings consuming a lot of energy, the department of energy building, according to engineers, was constructed in such a manner so as to cut down the energy usage.
From the outside, it looks like any modern structure.
“We have grid connected solar lightings on staircases and auto switch street lights,” an engineer with the department, Sherub Jamtsho, said.
The construction of the building that was completed in 2009 was supposed to have less running cost. But no studies have been done to compare costs.
Use of double glass in construction, engineers and architects say, is the right choice for Bhutanese climate. That is because it gives artificial light and saves energy.
Use of glass, architects and engineers say, is also energy efficient as it lets in natural light, thereby resulting in less use of electricity.
“Glass also traps heat and heat transmission through glass is still high compared to other building materials,” a civil engineer, Pema Tenzin, said. “Double glazing with air gap in between for insulation is good for Bhutanese climate.”
The old Motithang hotel, which is now the hotel and tourism management and training institute, was also converted into an energy-efficient building in 2005.
Sherub Jamtsho said saving components for ventilation, heating and hot water had been installed in the building without compromising the comfort.
Engineers and architects say most buildings in Thimphu are not energy efficient. An engineer, working for renewable energy, said the building codes Thimphu house owners incorporated are replicated from Indian buildings, which are designed for warm climate.
Citing the usage of tiles as an example, the engineer said, it’s important to incorporate materials and designs that suit our climate.
An architect, Tashi, said it’s important to design houses in accordance to orientation of the sun, so that maximum heat is absorbed to keep the rooms warm, and natural light can substitute artificial lighting system.
However, although the materials used in traditional Bhutanese buildings are energy efficient, high infiltration makes it less energy efficient.
He said that the rammed earth is considered more energy efficient than stone masonry, as the earth has high thermal mass and it absorbs heat during the day and retains it during the night.
By Tashi Dema