Canada adopts lower window-to-wall ratio proposal

By Katy Devlin, Glass Magazine
March 25, 2011
COMMERCIAL, FABRICATION : CODES & STANDARDS, MEETINGS AND EVENTS

Like the attempt at ASHRAE to reduce window-to-wall ratio in the prescriptive commercial building codes, similar moves to reduce glass have been proposed and passed in Canada, reported Margaret Webb, executive director, Insulating Glass Manufacturers Alliance, Ottawa, Ontario, at the association's Annual Meeting in Las Vegas.

Canada's Standing Committee of Energy Efficiency in Buildings fast -tracked a proposal to reduce the ratio, called the fenestration/door to wall area ratio, for prescriptive requirements. In the ASHRAE 90.1 proposal, the WWR would have been reduced to a blanket 30 percent. Under the SCEEB proposal, the FDWR would be set to a declining value based on heating degree days, using the quadratic equation.

"Instead of just setting a value, they used a creation based on heating degree days," Webb said. "While it wasn't going to have as significant of an impact as that of the ASHRAE proposal, it was serious enough to warrant attention." IGMA submitted a negative, as did the Canadian Home Builders' Association, proposing a compromise solution that would provide a lesser reduction in the FDWR. "The amount of the ratio improved by about 5 percent across [most parts] of Canada," Webb said.

The proposal, with the compromise ratio, was passed and the code is published. 

Read more news from the meeting.