Pervious paving is suitable for gentle inclines that slope no more than 1 foot over a horizontal distance of 20 feet. Though a small-scale paver or grid-system project like a pervious walkway or patio might be a DIY job, you’ll likely need professional design help for a driveway, where soil is heavy with clay or freezes deeply, or if the job is tied into a building permit. Pervious concrete (shown) and asphalt (which cost 20 percent more than their conventional counterparts) always require professional installation.
Plastic-grid systems are the most DIY-friendly, requiring a gravel base layer of only 2 to 6 inches, compared with about a foot for the other systems. The base can be tamped with a plate compactor, which you can rent; the material is simply rolled out and pinned down along the edges; and spaces are filled with decorative gravel or sand, plus grass seed, if you like.