The 2015 change in the Ontario Building Code that permits wood structures up to six storeys and the resulting surge in the construction of these buildings, seems to indicate that there is considerable support for larger wood structures in Ontario, but for practitioners wanting to pursue a wood structure taller than six storeys, there has been very limited practical support. Mass timber products, for example, are not specifically defined as a distinct material in the current Ontario Building Code and it is these mass timber products that make tall wood construction possible.
Mass timber products are large-scale, engineered wood components that are similar in definition to solid timber but otherwise fall under the classification of all other combustible construction materials. Since the building code has historically required tall buildings to be built of non-combustible construction, using any combustible material, including mass timber, for structural purposes was not an option in Ontario for a long time. Fortunately, things have now changed. Since the 2006 version of the Ontario Building Code came into effect, architects in Ontario have been freed from the compliance constraints of a single acceptable solution (prescriptive path). In 2006 the Ontario Building Code introduced a two-volume compendium that includes clause by clause descriptions of objectives and functional statements that support a new performance path approach to meeting the requirements of the building code...