Building Reuse - MRc1 Intent To extend the lifecycle of existing building stock, conserve resources, retain cultural resources, reduce waste and reduce environmental impacts of new buildings as they relate to materials manufacturing and transport Requirements Maintain at least 75% of the existing building structure (including structural floor and roof decking) and envelope (the exterior skin and framing, excluding window assemblies and non-structural roofing material) The intent and requirements described on this webpage are paraphrased from the copyrighted works of the USGBC "LEED 2009 for New Construction and Major Renovations Rating System November 2008", and, the CAGBC "LEED Rating System & Addendum for New Construction and Major Renovations LEED Canada-NC version 1.0 December 2004", and are presented here strictly for informational purposes and are not intended to supplant or be used in place of the original copyrighted works.