Tree Preservation By-Laws

Municipalities have established tree preservation By-Laws to regulate tree removal and injury. The goal being to preserve and grow our city’s tree canopy cover, ensure trees remain safe and stable and to encourage good Urban Forestry practice. Each Municipality has its own specific By-Laws in place. Below are some references and links for more information in our most frequently serviced areas.

Please contact us if you have any further questions or require assistance with obtaining a permit.

City Of Toronto Icon

A permit is required to remove or injure any tree on private property with a trunk diameter of 30cm or greater, measured at 1.4 meters above ground (endangered species are protected regardless of size).

A permit is required to remove or injure any sized tree on city property or conservation area.

City Of Markham Icon

A permit is required to remove or injure any tree on private property with a trunk diameter of 20cm or greater, measured at 1.37 meters above ground (endangered species are protected regardless of size).

A permit is required to remove or injure any sized tree on city property or conservation area.

City Of Richmond Hill Icon

A permit is required to remove or injure any tree on private property with a trunk diameter of 20cm or greater, measured at 1.4 meters above ground (endangered species are protected regardless of size).

A permit is required to remove or injure any sized tree on city property or conservation area.

City Of Vaughan Icon

A permit is required to remove or injure any tree on private property with a trunk diameter of 20cm or greater, measured at base of tree (endangered species are protected regardless of size).

A permit is required to remove or injure any sized tree on city property or conservation area.

How to Measure a Tree

Diameter at Breast Height

Diameter at breast height, DBH, is a standard way of expressing the diameter of a tree. DBH refers to the width of the tree trunk measured at 1.4 m above the ground (this is the standard method for Toronto but the height at which measurement is to be taken may vary depending on municipality).

Determining the diameter of a tree (DBH):

You can calculate the diameter of a tree (DBH) by dividing the value of its circumference (C) by number pi (∏ = 3.1416). DBH = C/∏.

Circumference is the distance around the trunk. To determine DBH, circumference must be measured at 1.4 m (4 ½ feet) above ground level.

Divide the measured circumference value by 3.1416. This will give you the DBH value. A tree with a DBH of 30 cm (12 inches) has a circumference of 94.2 cm (37 inches).

Measuring the diameter of a tree growing on an angle

For trees growing on an angle from a horizontal grade and for trees growing vertical on slopes, the diameter shall be measured at right angles to the stem 1.4 metres along the centre of the stem axis.

Measuring the diameter of a double-stem or multiple stem tree

For double-stem or multi-stemmed trees, the diameter measurement is to be taken at a height of 1.4 metres above ground level for each stem. Where at least one stem measures 30 cm in diameter or greater, the tree (including all stems) is protected under the by-law. The diameter of the largest stem is used to determine the TPZ for the multi-stemmed tree (this formula is the standard in Toronto but may vary depending on municipality, ask your Arborist or contact your local Forestry Department).