Trapped smoke lays bare gap in design norm


In December 2011, more than 90 persons died in a hospital fire when smoke trapped in the glass-encased building travelled through it, smothering the patients. Aspirations Vintage, the building on Pretoria Street that was granted a completion certificate two years after the tragic fire, had the same glass facade without any windows. When a fire broke out in the building on Thursday, smoke got trapped yet again, unable to escape in the absence of openings. It could have turned into another death chamber had not occupants been rescued in time.

Most present-day architects prefer glass facades in commercial buildings, choosing it for functionality, elegance and economy while ignoring the peril it poses in exigency like fire. Speaking to TOI on Thursday, architects admitted buildings encased with glass could turn into tombs but pointed out the practice would continue till the National Building Code was amended.

JP Agrawal, who has designed several buildings with glass facade in Kolkata and Salt Lake, said the absence of a clear guideline on an opening in the facade led to the ambiguity. “The National Building Code states that space equivalent to 15% of the floor area should be available for light but there is nothing prescribed for smoke,” he said, adding that he personally believes at least 5% area should be reserved for windows to allow natural ventilation.

In a 200 sq ft room, the rule requires 30 sq ft transparent glass on one of the walls, not a window. According to Agrawal, the room should have at least a 10 sq ft window. But in the absence of a guideline, designers don’t take a window into account. In fact, windows are often not a part of an office or commercial building design as they are seen as making an air-conditioned building inefficient.

Malay Ghosh of architect firm Espace that designed 12 Pretoria Street said the glass building was a heritage conservation project. “The Grade IIB heritage building with neo-classical architecture required the facade to be retained while changes could be made to the rest. Instead of keeping only the facade, we kept the first grid of the three layers of rooms. In the space that was created after demolishing the rear portion, a building with a simple glass facade was designed to reflect the heritage structure in front and relate to its history and past. That is the idea behind the glass pyramid in the Louvre in Paris too,” he pointed out.

While the glass panels that faced the street were sealed, Ghosh said there are windows at the rear of the building. He wondered why they weren’t opened to let the smoke out. Perhaps, the occupants rushed out in panic instead of spending precious time to open windows.

Both Ghosh and Agrawal blamed poor maintenance for the mishaps. At 12 Pretoria Street, fire alarm, water sprinklers and fire hydrants didn’t function. “Sprinklers are supposed to suppress fire. If they function, there is no problem with glass buildings that have multiple advantages. They allow natural light, reduce heat transfer into the building and quick to set up,” he reasoned.

After Thursday’s fire, Ghosh says future designs by his firm will incorporate a window after every 5-6 metre, which would help not just in case of fire but in the event of a power failure when air-conditioning shuts down.


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