The following is an elementary formula for determining the number of shade trees required in and around paved parking lots in order to presumptively satisfy the shading requirements of § 208-2200:
1. Including parking spaces, driveways, loading areas, sidewalks and other circulation areas and not including building area or any area which will remain completely undeveloped, calculate square footage of the vehicle accommodation area:
2. MULTIPLY ____square feet x .20
3. EQUALS: area to be shaded ____square feet
ADD:
4. Area shaded by existing trees to be retained
in and around the vehicle accommodation area*: ____square feet
5. Area shaded by required screening trees,
if any*: ____square feet
6. Area shaded by required street trees,
if any*: ____square feet
7. EQUALS: subtotal: ____square feet
[If line 7 is greater than line 3, then the shading requirement has been met. If not, go to line 8.]
8. Enter the difference between line 7 and
line 3: ____square feet
9. DIVIDE line 8: ____/707
10. EQUALS:
Total number of shade trees required within the vehicle
accommodation area: ____trees
NOTES:
* Existing trees retained in compliance with Article VIII will be credited according to their actual crown radius. Shaded area may be calculated as follows:
3.14 x (crown radius)2 = shaded area
Trees planted within the vehicle accommodation area are credited with shading seven hundred seven (707) square feet [based on a crown radius of fifteen (15) feet]. New or existing trees on the perimeter of the parking lot are credited for having only half a crown over the vehicle accommodation area [e.g., new perimeter trees will be credited for shading three hundred fifty-four (354) square feet]. When smaller trees such as dogwoods are planted, the credited shading area will be adjusted downward to three hundred fourteen (314) square feet for interior trees and one hundred fifty-seven (157) square feet for perimeter trees [based on a crown radius of ten (10) feet].
