A suggested base set up for our permeable pavers to be laid in Non-Trafficable areas: (i.e. no cars driving on them), would be as follows:
 

• One layer of A14 geotech cloth
• Minimum of 100mm of compacted 7/20mm drainage metal
• 2nd layer of A14 geotech cloth
• 25mm of 3-6mm compacted metal
• Permeable pavers 300sq. or 400sq. x 50mm thick

A suggested base set up for our permeable pavers to be laid in Trafficable areas as follows: 

• One layer of A14 geotech cloth
• minimum of 150mm of compacted 20/40mm drainage metal
• 2nd layer of A14 geotech cloth
• 25mm of 3-6mm compacted metal
• Permeable pavers 230 x 115 x 50mm

Further Considerations:

Novacoil under drain should be installed where possible to base to pick up excess soakage
Perimeter of pavers to be locked in
Please note that this specification is subject to ground porosity and bearing strength.

Onsite Base Setup photos