What percentage of permeable paving is required for Tier 1 CALGreen projects?

For Tier 1 CALGreen projects, the requirement is set at 20% of the total paved area to be permeable paving. This measure is aimed at mitigating the impacts of stormwater runoff by allowing rainwater to infiltrate the ground, thereby reducing the volume of water that exits the site and improving water quality. The inclusion of permeable surfaces contributes to the overall sustainability goals outlined in CALGreen, promoting environmental stewardship and effective water management practices in California. Adhering to this percentage not only helps in regulatory compliance but also enhances the ecological performance of a site.