The motive behind new green building practices is a good one, but a recent report by the B.C. Construction Association has uncovered some worrying problems with modern green building practices. According to the report, some of the practices that are encouraged by green building policies could be creating long term risks and liabilities.
Manley McLachlan, president of the BCCA, said that the report was “not a statement opposed to sustainable building”, but wanted to stress that there are holes in the current rules, and that some builders were failing to plan ahead.
One such example is the wood that is used throughout construction, as everything from roofing supplies to structural supports. Under the LEED certification system, new builds get credit for making use of construction materials sourced from trees that grow and are replaced quickly. Woods from those trees are more prone to mould growth.
It’s not just roofing supplies and other construction materials that are problematic. Low VOC, non-toxic paints may be lower impact in the short term, but many of them aren’t suitable for use on a building’s exterior, as they are not as weather-resistant as traditional paints.
More Testing is Required
The BCCA is concerned that the increasing use of green roofs, sustainable construction materials, and low VOC paints could lead to a crisis similar to the “leaky condo” problem of a few years ago. The believe that the new building practices have not had enough testing, and that they are not yet proven to be as long-lasting, and sturdy, as traditional buildings.
The report does not go so far as to say that new practices are unsafe. The main concern is a financial one – new building techniques are being developed with a view to earning “green points”, but the techniques and materials are being deployed without extensive testing, and with limited training for construction workers. Developers are offering warranties relating to the durability and effectiveness of these new techniques, and they can’t be certain that in a few years’ time, a huge number of people will end up calling those warranties in.
Innovative building practices may carry some risk, but the risk from home-owners taking green practices into their own hands is a bigger concern. In some parts of the world, homeowners are installing their own green roofs (also known as living roofs). These roofs have vegetation on them, and offer both indirect environmental benefits, and energy savings. In the winter, green roofs act as a form of insulation. However, if they are not maintained properly then they can be a fire hazard in the summer, when dry weather and high temperatures effectively turn the vegetation into tinder.
Innovation Always Carries Risk
There is always some risk associated with innovation, whether that is the application of new materials in roofing supplies, or the use of new energy systems. The report from the BCAA raises a lot of questions, and will hopefully inspire new waves of testing and research into safe construction. We should not abandon green building practices because of a handful or reports raising concerns, but slowing down and considering how to make our buildings safer is always a good idea.
Photo: Alexandre Prévot