§ 155.124 CALCULATION.
   (A)   Any development site greater than two acres in size shall be permitted to determine the area of existing tree canopy coverage to be preserved by ground checking, aerial analysis, or any other method determined to be accurate by the DPDS staff. If ground checking is utilized, then each individual tree (i.e., a tree not grouped with other trees or a part of a tree stand) intended to be retained and used to meet the tree canopy requirements herein shall be measured to determine its caliper and the credit given for that tree shall be in accordance with the first table in division (E) below.
   (B)   For any development site two acres or less in size, the area of tree canopy coverage for any group of trees to be retained in order to meet the tree canopy requirements of this section shall be determined by ground checking. Credit for existing trees intended to be retained may be calculated in either of two ways:
      (1)   Measurement of the trunk to determine its caliper and the credit given for that tree shall be in accordance with the first table below; or
      (2)   The dripline may be plotted on the site plan and tree canopy credit given for the percentage of the site within the dripline.
   (C)   New trees planted to meet the requirements of this subchapter shall be given credit in accordance with the first table below. Such trees must meet the standards of §§ 155.165 through 155.179 at the time of planting.
   (D)   Street trees planted in accordance with § 155.147 shall qualify for a 25% bonus in the amount of credit listed in the first table in division (E) below. This credit shall apply to street trees that are mandated as well as those planted on a voluntary basis.
   (E)   In calculating the required number of trees, fractions less than one-half shall be dropped and greater than or equal to one-half shall be rounded up.
Deciduous Tree Canopy Credit
Caliper
Tree Type**
Amount of Credit (per tree)
Caliper
Tree Type**
Amount of Credit (per tree)
10 inches or greater
Type A
1,200 square feet (100% mature canopy size)
Type B
720 square feet (100% mature canopy size)
Type C
177 square feet (100% mature canopy size)
Greater than or equal to 1 inch and less than 1 3/4 inches*
Type A
600 square feet (50% mature canopy size)
Type B
360 square feet (50% mature canopy size)
Type C
89 square feet (50% mature canopy size)
Greater than or equal to 1 3/4 inches and less than 3 inches
Type A
720 square feet (60% mature canopy size)
Type B
432 square feet (60% mature canopy size)
Type C
106 square feet (60% mature canopy size)
Greater than or equal to 3 inches and less than 10 inches
Type A
960 square feet (80% mature canopy size)
Type B
576 square feet (80% mature canopy size)
Type C
142 square feet (80% mature canopy size)
* See §§ 155.165 through 155.179 for criteria to plant trees less than 1 3/4 inch caliper.
** Trees are categorized as A, B, and C - large, medium, and small; refer to § 155.178 for species that fall within each category
 
Evergreen Tree Canopy Credit
Height
Tree Type*
Amount of Credit (per tree)
Height
Tree Type*
Amount of Credit (per tree)
15 feet and greater
Type A
1,200 square feet (100% mature canopy size)
Type B
720 square feet (100% mature canopy size)
Type C
177 square feet (100% mature canopy size)
Greater than or equal to 6 feet and less than 9 feet
Type A
720 square feet (60% mature canopy size)
Type B
432 square feet (60% mature canopy size)
Type C
106 square feet (60% mature canopy size)
Greater than or equal to 9 feet and less than 15 feet
Type A
960 square feet (80% mature canopy size)
Type B
576 square feet (80% mature canopy size)
Type C
142 square feet (80% mature canopy size)
* Trees are categorized as A, B, and C - large, medium, and small; refer to § 155.178 for species that fall within each category.
 
   (F)   (1)   Note: Street tree bonus: for example, a development that provides three Type A trees two inches in caliper shall receive credit for 2,250 square feet of tree canopy.
      (2)   Note: The first table in division (E) above gives credit for 50% of the mature canopy size when a one and three-fourths-inch to three-inch caliper tree is planted.
      (3)   CALIPER. The diameter of a tree trunk, measured six inches above the ground for newly installed trees and at four feet six inches above the ground (breast height) for existing trees.
(LDC § 10.1.5)