Frequently Asked Questions
What is mass timber?
Mass timber refers to large dimension solid lumber, glued-laminated lumber (glulam), cross-laminated lumber (CLT) or other large dimension wood products as opposed to conventional stick-frame construction typically used in
low-rise and mid-rise buildings. With advanced construction technologies and modern mass timber products, building tall with wood is not only achievable but already taking place around the world.
Why was a mass timber structural system selected for The Arbour?
Mass timber offers several advantages, including improved dimensional stability and better structural and fire safety during construction and occupancy. These new products are also prefabricated, which offers tremendous opportunities
to improve the speed and quality of construction in tall building applications.
The use of mass timber components for The Arbour represents a ‘Made in Canada’ approach that will showcase Ontario as a leader in sustainable timber construction. As the first mass-timber, low-carbon institutional building
in the province, The Arbour will serve as a practical example of what can be achieved with advanced wood products in construction.
Is mass timber construction safe?
Advancements in building technology and research, coupled with the rigorous five-year process for building code changes ensures that safety is of the utmost importance for every building, regardless of the materials used.
Recent case studies of modern mass timber buildings in Canada and around the world showcase the fact that wood is a viable solution for attaining safe, cost-effective and high-performance tall buildings. For more information,
refer to the following case study and references: Brock Commons Tall Wood House (Canadian Wood Council) .
What about fire?
Mass timber has inherent fire resistance due to charring which tends to protect residual wood as it acts as an insulator. Moreover, it is quite difficult to ignite mass timber elements in a building (i.e., columns, beams, floors)
due to their massive sizes. Often, mass timber buildings are fully or partially encapsulated with gypsum or cement boards which further protect the wood from being engaged in fire. Tall mass timber buildings are also required
to have active fire suppression systems such as sprinklers which are the first line of defence in the event of fire. Typically, mass-timber buildings are equipped with smoke and fire alarms to further enhance the fire safety.
Why build tall with wood?
The use of wood in tall buildings offers some significant advantages, including:
- the ability to build higher in areas where poor soils exist – a wood superstructure is lighter than other building materials and therefore, has reduced foundation requirements;
- a quieter construction site - neighbours are less likely to complain and workers are not exposed to high levels of noise due to the high level of prefabrication involved;
- improved worker safety – safety during construction can be improved with the ability to work off large mass timber floor plates that have already been machined at the plant to facilitate easy on-site assembly by the small
number of crew involved;
- shorter construction times - prefabricated components manufactured off-site can be shipped and installed relatively quickly, reducing the overall duration of construction which has huge positive financial implications;
- and improved energy performance – wood’s natural thermal resistance combined with tight tolerances in the building envelope assembly can produce buildings with high operational energy performance, increased air tightness,
better indoor air quality and improved human comfort.
Wood products store/sequester carbon absorbed by the trees while growing. Buildings constructed with mass timber are particularly advantaged when it comes to carbon sequestration because of the high wood volume in mass timber
panels, columns and beams. As a low-carbon material, wood has significant potential to reduce the overall GHG (greenhouse gas) emissions of the building sector compared to other energy-intensive material. Mass timber has
the potential to be reused or repurposed in the event of disassembly at the end of the project’s life, thus allowing for longer carbon sequestration and reuse of construction materials.
Life cycle assessment studies consistently show that wood outperforms other construction materials, in identical applications, in terms of embodied energy, air and water pollution and global warming mitigation.
Are mass timber buildings all wood?
Mass timber buildings are hybrid structures that incorporate systems comprised of several building materials for foundations, the first floor or for elevator and stairwell shafts. By including wood as a structural option in
taller construction we can benefit from the many advantages wood offers, while still incorporating other materials like steel and concrete where their use makes the most sense, ultimately making the best use of all our
How much will it cost to build The Arbour?
The Arbour will cost approximately $130 million to build.