Fenestration Forum: February 2013
By Brian Burton
By Brian Burton
The Canadian glass construction industry has benefited greatly from over
50 years of technical input and indirect assistance from the National
Research Council and the Institute for Research in Construction.
The Canadian glass construction industry has benefited greatly from over 50 years of technical input and indirect assistance from the National Research Council and the Institute for Research in Construction. The Canadian Construction Materials Commission has also played a role by fostering continuing innovation in the industry. I have written on a number of occasions about the tremendous importance of the construction industry, which rarely receives the attention it warrants as one of Canada’s largest economic sectors. In 2009, its contribution was $69.1 billion while providing employment to hundreds of thousands of Canadians, according to Statistics Canada. Significant economic and social benefits have been derived from the National Model Building Code, which was introduced in 1941. The development of our model building code system can actually be traced to the postwar housing boom in the 1930s and work on code development began in earnest in 1937. In 1986, the Division of Building Research became part of the NRC. The NRC had, and still does have, a focus on many other specialized industries in addition to construction including transportation, manufacturing, technology transfer, telecommunications and many other advanced and developing technologies.
One of the major initiatives undertaken by the NRC involved the production of the Canadian Building Digests, which began in earnest in the early ’60s when a core group of researchers began producing the well-known series. The CBDs were modelled on similar material that was published by the British Building Research Establishment, which has been in continuous operation since 1917 and is now a non-profit trust. As a monthly publication, the CBDs reached many thousands of readers including architects and building designers. At the time they started producing the CBDs there was a focus on dealing with condensation issues and developing methods to avoid the repeated wetting and drying of construction materials and the costly effects this had on buildings in Canada’s extreme climate. When it came to cold weather construction, there were certain factors relating to building performance that attracted the attention of government researchers. For example, in addition to condensation, the movement of moisture in relation to indoor and outdoor environmental conditions, air leakage and the thermal performance of various elements contained within the building envelope were considered problematic and complex from a building science point of view. The CBDs eventually addressed what came to be known as the “open rain screen” concept and also explored the stack effect, ice lensing and the analysis of structural movement and deflection. Much of this research was driven by the increasing trend toward high-rise commercial office buildings.
The energy crisis in the early 1970s drew attention to energy conservation measures which have continued to the present time. Some of the information gained from the production of the CBDs eventually led to publication of the 1983 book Building Science for a Cold Climate, which is still considered relevant today. The CBDs also dealt with issues relating to health and safety, acoustics, technology transfer, daylighting design, and many other factors that affect the overall performance of buildings, construction materials, and occupant comfort and productivity. You can access 240 CBDs online at http://archive.nrc-cnrc.gc.ca/eng/ibp/irc/cbd/digest-index.html.
In total, this group of researchers at the NRC produced 250 CBDs, of which fenestration was the subject of close to 20. In many ways, the CBDs trace the development of our understanding of cold weather building science. The CBDs continued to be issued until 1988 and they are still available in printed form from the NRC.
In my opinion, there is certainly a lot to be gained from revisiting and rereading these important documents. They definitely enhanced our understanding of performance of buildings in cold weather and there are many countries that would benefit from Canada’s substantial investment in this unique field.
Brian Burton is the author of Building Science Forum and is serving on CSA’s Fenestration Installation Technician Certification Committee. Brian is a research and development specialist for Exp. He can be reached at firstname.lastname@example.org.