Ontario now allows developers to build huge towers made of wood

An update to the Ontario Building Code that just came into effect with the dawn of 2025 should mean quieter, more eco-friendly and, perhaps more importantly, faster construction of new homes across the province in the years to come.

Introduced by Minister of Municipal Affairs and Housing Paul Calandra in the spring, the amendment pertains to mass timber buildings, which were previously subject to significant height restrictions, initially to up to six storeys until 2022, then to 12 storeys.

As of January 1, developers can now design encapsulated mass timber developments of up to 18 storeys, which the Province says will “help the sector build more homes faster, keep the cost of construction down and boost our northern economy,” among other benefits.

Mass timber refers to complexes that use structural load-bearing components made of wood, often in multiple layers that are glued, dowelled or nailed and laminated together.

Contrary to outdated perceptions about the building material, it must meet comparable structural, fire protection and seismic performance criteria as concrete and steel. Buildings that use it are also faster and less disruptive to erect, as beams, columns, panels and more arrive at the site pre-fabricated and treated. 

Additionally, mass timber is lighter, easier to work with (compared to, say, temperature-sensitive concrete), more aesthetically pleasing and far more sustainable than other mediums.

Increasing the permissible size of such structures reflects a growing trend of incentivizing mass timber construction, and housing construction more generally, not just in Ontario but across Canada.

Other changes to the Building Code Act as of January 1 will also help “streamline Ontario’s Building Code and reduce barriers between provinces by increasing harmonization between Ontario’s Building Code and the National Construction Codes,” the province says.