Can Heritage Buildings Be Called Green?
The keefer before its very jazzy renovation
We spend a lot of time saying that Heritage buildings are green, but Vancouver architect Gair Williamson, who has worked on a lot of them, says only "sort of" in an interview with a construction industry newspaper.
"A building constructed in 1904 is not going to perform to modern standards. If we were to take the Keefer project and bump it up to LEED standards, it would be unrecognizable as a heritage building. If they replaced the single-pane windows with double-panes, for example, it would lose the character that made the building iconic."
He makes some very good points that most architects miss when they work on old buildings- that they need to leak a bit.
"If we add showers and kitchens to these buildings, we have to add a semi-permeable sealer to the walls so that it lets the air in and lets the vapour back out as well. That helps to preserve the brick walls constructed with 100-year-old technology.
"Even some of the timbers in these buildings look like they've come fresh out of the sawmill. If you put up a full vapour barrier, these building components begin to age exponentially."
But I think he is off the mark when he says:
"An existing building is an invested resource of energy and material." By preserving that, we're meeting some of the goals of green building, but by any performance-based standards, these buildings are not green."
Of course there is a lot more to performance than just energy. There is the issue of durability, natural light and ventilation, use of healthy materials. But there are numerous examples (like 401 Richmond Street in Toronto) that show that older buildings with opening windows and walls with a lot of thermal mass use less energy and resources than newer ones. Studies have also shown that properly restored single glazed windows can perform very well, particularly if storm windows are installed.
There are lots of reasons to save old buildings, and Williamson is really good at it. But from any life-cycle analysis point of view, and even from a total energy consumption point of view, they can perform well. I think he understates their case here.