To preserve existing noninvasive trees, native plants, and pervious surfaces.
Option 1. Development footprint on previously developed land (1 point)
Option 2. Undeveloped portion of project left undisturbed (1 point)
Depending on the density of the project, do not develop or disturb a portion of the site that has not been previously developed, exclusive of (1) any land preserved by codified law, (2) a prerequisite of LEED for Neighborhood Development or (3) exempt areas designated as nonbuildable in comprehensive land-use plans. Stipulate in covenants, conditions, and restrictions (CC&R) or other binding documents that the undisturbed area will be protected from development by a private or governmental agency for the purpose of long-term conservation. When determining the minimum area to be left undeveloped, mixed-use projects must use the lowest applicable density from Table 1 or use the weighted average methodology in NPD Credit Compact Development. Densities and minimum percentages are as follows:
Table 1. Minimum undeveloped area, by project density
|Residential density (DU/acre)||Residential density
|Nonresidential density (FAR)||Minimum area left undisturbed|
|< 13||<32||< 0.5||20%|
|> 13 and ≤ 18||> 32 and ≤ 45||≥ 0.5 and ≤1||15%|
|> 18||> 45||> 1||10%|
DU = dwelling unit; FAR = floor-area ratio
For portions of the site that are not previously developed, identify construction impact zones that limit disturbance to the following:
- 40 feet (12 meters) beyond the building perimeter;
- 10 feet (3 meters) beyond surface walkways, patios, surface parking, and utilities less than 12 inches (30 centimeters) in diameter;
- 15 feet (4.5 meters) beyond street curbs and main utility branch trenches; and
- 25 feet (7.5 meters) beyond constructed areas with permeable surfaces (such as pervious paving areas, stormwater retention facilities, and playing fields) that require additional staging areas to limit compaction in the constructed zone.
For all projects
Survey the site to identify the following:
- trees in good or excellent condition, as determined by an arborist certified by the International Society of Arboriculture (ISA) or local equivalent professional for projects outside the U.S.;
- any heritage or champion trees of special importance to the community because of their age, size, type, historical association, or horticultural value, as defined by a government forester;
- all trees larger than 6 inches (15 centimeters) in diameter at breast height (dbh, 4 feet 6 inches [1.4 meters] above ground); and
- any invasive plant species that affect trees present on the site, and whether those plants threaten the health of other trees to be preserved on the site, as determined by an ISA-certified arborist or local equivalent professional.
Preserve the following trees that are also identified as in good or excellent condition:
- all heritage or champion trees and trees whose dbh exceeds 50% of the state champion dbh for the species;
- a minimum of 75% of all noninvasive trees (including the above) larger than 18 inches (45 centimeters) dbh; and
- a minimum of 25% of all noninvasive trees (including the above) larger than 12 inches (30 centimeters) dbh if deciduous and 6 inches (15 centimeters) dbh if coniferous.
Tree condition ratings must be determined by an ISA-certified arborist using ISA-approved assessment measures or by a local equivalent professional utilizing an equivalent methodology.
Develop a plan, in consultation with and approved by an ISA-certified arborist or equivalent, for the health of the trees, including fertilization and pruning, and for their protection during construction.
If an ISA-certified arborist or local equivalent professional has determined that any trees to be preserved are threatened by invasive vegetation, develop a plan to reduce the invasive vegetation. Stipulate in codes, covenants, and restrictions or other binding documents that the undisturbed area of the preserved trees will be protected from development by a private or governmental agency for the purpose of long-term conservation.
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