the larger design goals, as well as transitional mechanisms and necessary compromises entailed in gradually closing the loops and tightening material cycles. In the spirit of the hierarchy of priorities for materials efficiency summarized in Chapter I, a ladder of priorities in building for the circulation of materials includes: maintenance and conservation of buildings renovation and reuse of buildings reuse of building elements material reuse material recycling material downcycling material disposal. Both the green building and recycling movementsthrough networks like the Healthy Building Network and the Grassroots Recycling Networkhave persistently expanded their perspectives to prioritize more fundamental solutions to waste expressed in the notion of zero-waste (Seldman, 2003). This chapter will generally follow the ladder of priorities for a zero-waste strategy in the construction industry, beginning with the building level and moving toward the materials level.