Moving towards a hotter drier climate, glass towers and their associated solar reflection and heat refraction are going to become major issues. Many people in Vancouver’s glass towers left their homes during the heat dome last month as internal temperatures were too high to be livable.
It turns out it is not only the glazing, but the shape of the glass that needs to be carefully considered in design.
The M2@Main Alley building is a new commercial building located at 4th Avenue and Quebec Street. The building experienced a fire last month which was caused by reflecting light.
Currently under construction with a summer opening date, this Westbank constructed building has an unusual curvilinear glass wall on the higher storeys.
It was that shaped surface on the eighth floor that caused the fire, reported by the Vancouver Fire Department as being started by sunlight magnified by the curved windows.
As reported by Nafeesa Karim with CTV News, the fire was extinguished, but Vancouver Fire and Rescue Services Assistant Chief Of Operations noted that the blaze was similar to the incident that happened in London, Great Britain with the Fenchurch or “Walkie-Talkie” tower in 2014. Newly built at the time, this building also has a curvilinear window shape and had a reflective surface strong enough that reflected light from the tower damaged cars and melted paint on storefronts on the adjoining street.
Describing the situation in the Vancouver building fire, Trevor Connelly of Vancouver Fire Rescue Services stated in The Independent
As more and more of these high rises go up with glass fronts, we want people to be aware … The sun gets magnified passing through a piece of glass, but we don’t find it happening in flat glass. It’s the curved nature of glass that creates the magnifying effect.”
In Vancouver foam insulation in the roof caught on fire, but was quickly suppressed by the Vancouver Fire Department. In the case of London’s Fenchurch “Walkie-Talkie” tower, the solution was to stop the direct rays of the sun on the building by creating a giant canopy.
You can see in the YouTube video below a reporter talking about the Fenchurch (Walkie-Talkie) building, which during two hours a day reflected light and uncomfortable heat onto the shopping street below. The reflected heat was so hot it cracked tiles, blistered paint, and increased street temperatures over 40 degrees celsius, making walking in the area very uncomfortable. This added to the building’s claim of the 2015 Carbuncle Cup award winner for the ugliest newly constructed structure in Great Britain.
There’s a second YouTube video following with Math whiz Matt Parker describing the physics behind why the Fenchurch building overheated the street, why curving glass tower walls are a bad idea, and al describing the worse possible shape to ever construct for light reflection. He does a great job, and there’s nearly 500,000 views of the video.