Last week, at the international conference on urban development and wellbeing, an architect, Deependra Pourel, said it is important that the country should have set building standards to preserve traditional architecture, with space standards for quality living and ensure seismic resistant structures. 

However, Bhutan’s urban infrastructure and buildings, according to him lack thermal comfort, adequate ventilation, daylight and access to sunlight. The expanding city, he said, is vulnerable to urban heat island effect due to concrete structures replacing natural vegetation. 

Urban heat island effect occurs on a particular part of land where there is a vast temperature difference between a city and its surrounding land. 

From January to April this year, Semtokha meteorology station recorded the highest of 27 degree Celsius in the city. However, there is no separate data on the difference in temperature between the core town area and the outskirts of the city with the National Centre for Hydrology and Meteorology (NCHM). 

Deputy Chief of Weather and Climate Services Division in NCHM, Tayba Buddha Tamang said there would be some difference in the temperature between the core town area and the outskirts of the city where there is dense vegetation. 

The reasons, according to him are that the number of buildings found in urban areas have dark surfaces. Dark surfaces absorb more sunlight, and heat, making the entire building warmer. Buildings with brick walls and dark coated roofs also heat up quickly. The heat is transferred both inside the structure and radiated into the surrounding air. Rising numbers of vehicle emission in town areas also contribute to the effect. 

Narrow streets and tall buildings also hinder air circulation, he said, which impacts the wind speed, thus reducing natural cooling effects. 

Deependra Pourel said planners need to consider three aspects of design—site characters, client’s brief, and local bylaws. 

Site characters include the geography, land topography, climate, and land profile while the client’s brief are size and shape of the infrastructure, orientation, building functions, and facilities.  

“To achieve that, Bhutan would need to unlock weather and climate data that we have collected over the years,” he said.