Ontario’s Ministry of Municipal Affairs and Housing announced on April 8 amendments to the Ontario Building Code allowing encapsulated Mass Timber Construction (MTC) buildings up to 18 storeys. It opens up a number of interesting issues. This proposal would put Ontario on par with the 2021 International Building Code (IBC) and see it join BC and 28 US states that have adopted the provisions. …Ontario’s announcement goes beyond the code amendment itself and speaks about potential benefits of MTC in terms of the province’s affordable housing shortage. …Any increased production of MTC components has environmental implications founded in concerns over tree harvesting, an animated ongoing debate. It boils down to the basic question regarding which is better: a mature tree standing in a forest; or a portion of that tree harvested. …The worst outcome is rampant clear-cutting and a series of unmanaged forests, combined with the burning of wood scrap for heat or energy.