Yes, maintaining existing material can be considered equivalent to installing reclaimed material. However, credit may only be awarded if 90% of the component (45% in the case of flooring) in the final LEED home meets the credit requirement. For example, if all of the original interior wall framing in a home is maintained, but the final LEED home includes new additions such that only 75% of the final interior wall framing is EPP, then no credit should be awarded.
Updated 10/1/13 for rating system applicability.