When recycled material is to be used for hard landscaping, the Green Guide rating will depend on whether the material comes from the same site or from another location.
Typically, on-site recycled material is treated with very little impact, or ignored, as there is little or no energy/material input in putting it in place. When recycled material is brought in from elsewhere, transport, as well as any processing the material has gone through to make it fit for purpose, will be taken into account.
If the assessor is in doubt, they need to submit a landscaping proforma along with any supporting documentation on the materials and their use and BRE will provide a rating and/or guidance.