goes to a form of recyclingin road beds for new highways. But this is largely downcycling, and in an ecological society, highway area should be considerably reduced. Design for disassembly is a necessity if concrete is to be properly reused, and improved recycling depends on better separation of concrete-masonry streams of undiluted concrete rubble, undiluted masonry rubble, mixed stony material, and mixed C&D waste (as discussed in Chapter II). Brick: Brick can and should be reused more, but this depends on more appropriate use of brick, separation between different kinds of brick in deconstruction, and the use of mortar which is better suited to disassembly. Interior bricks (salmons) and exterior bricks (hardburned) currently tend to get mixed up in demolition; they should be kept separate to be reused appropriately. The biggest cost of reusing brick is clean-up. The Portland cement that is currently used is too hard and strong for the reuse of brickmaking clean-up difficult and costly (Webster, 2002). As with wood, lead paint contamination can be a problem for older brick. Steel: Steel is also a material with great potential utility for design for deconstruction due to its ease of recycling through a thermal process and ability to span large distances with less mass of material than concrete for instance (Guy & Shell, 2002). But currently, while it is often recycled now (about 40 percent), it is rarely salvaged (Webster, 2002). Although an improvement over virgin steel-making, recycling is very energy-intensive; while the impacts of salvaged steel are mainly in its transport and refabricationwhich are much less than recycling. One of the most interesting features of the Phillips EcoEnterprise Center (PEEC) in Minneapolis was its incorporation of salvaged steel joists.