In climate zones 1 through 6, as established in the International Energy Conservation Code, not less than 50 percent of the site hardscape shall be provided with one or any combination of options described in Sections 408.2.1 through 408.2.4. For the purposes of this section, site hardscape shall not include areas of the site covered by solar photovoltaic arrays or solar thermal collectors.
Hardscape materials shall have an initial solar reflectance value of not less than 0.30 in accordance with ASTM E 1918 or ASTM C 1549.
Exception: The following materials shall be deemed to comply with this section and need not be tested:
- Pervious and permeable concrete pavements.
- Concrete paving without added color or stain.
Where shading is provided by a building or structure or a building element or component, such building, structure, component or element shall comply with all of the following:
- Where open trellis-type, free-standing structures such as, but not limited to, covered walkways, and trellises or pergolas, are covered with native plantings, the plantings shall be designed to achieve mature coverage within five years;
- Where roofed structures are used to shade parking, those roofs shall comply with Section 408.3 in climate zones 1 through 6; and
- Shade provided onto the hardscape by an adjacent building or structure located on the same lot shall be calculated and credited toward compliance with this section based on the projected peak sun angle on the summer solstice.
Where shading is provided by trees, such trees shall be selected and placed in accordance with all of the following:
- Trees selected shall be those that are native or adaptive to, the region and climate zone in which the project site is located. Invasive plant species shall not be selected. Plantings shall be selected and sited to produce a hardy and drought resistant vegetated area;
- Construction documents shall be submitted that show the planting location and anticipated ten year canopy growth of trees and that show the contributions of existing tree canopies; and
- Shading calculations shall be shown on the construction documents demonstrating compliance with this section and shall include only those hardscape areas directly beneath the trees based on a ten year growth canopy. Duplicate shading credit shall not be granted for those areas where multiple trees shade the same hardscape.
Pervious and permeable pavements including open grid paving systems and open-graded aggregate systems shall have a percolation rate not less than 2 gallons per minute per square foot (100 L/min × m2). Pervious and permeable pavement shall be permitted where the use of these types of hardscapes does not interfere with fire and emergency apparatus or vehicle or personnel access and egress, utilities, or telecommunications lines. Aggregate used shall be of uniform size.