Permits are required for the removal or major trimming of any viable tree on private property that has a trunk greater than 30 cm in diameter. If the tree in question is no longer viable, that is it is dead, diseased or poses a significant risk to life or property, it is exempt from permitting requirements. All city owned trees also require permitting for removal or alteration. We recommend contacting an ISA Certified Arborist company if you are unsure about the permitting requirements for your specific situation or to receive additional clarification regarding the Toronto Tree Bylaws. Local Arborist offers complimentary consultations and estimates for all tree care services.