What must permeable paving include to earn points for the Sustainable Sites credit for Permeable Paving?

Permeable paving must include a porous sub-base to earn points for the Sustainable Sites credit for Permeable Paving. This porous sub-base plays a crucial role in allowing water to permeate through the paving material, promoting groundwater recharge and reducing stormwater runoff. The design of permeable paving focuses on the ability of the surface and underlying layers to drain water effectively, which is essential for maintaining hydrology and mitigating flooding.

The porous sub-base works in conjunction with the surface materials to create a system that facilitates the natural infiltration of rainwater. This not only helps in managing stormwater but also contributes to the overall sustainability of the site by preserving the natural water cycle. Therefore, the inclusion of a porous sub-base is a critical component in meeting the requirements for the Sustainable Sites credit.