Whether they're looking to steal copper pipe, or just lay some of their own, people who lurk around construction sites are usually up to no good. Loitering for a nobler purpose, Lucky Sustainable Designs.
Lucky was started by a Houstonite who years ago began using wood found in building zones, razed neighborhood lots, and other cast-off goldmines to build hefty pieces of furniture; not wanting to waste the tinier bits, she started crafting smaller stuff, at first for friends, and now for any Lucky bastard who finds her online. The mainstay's lathe-turned, non-toxic-shellac'd bottle stoppers with tapered rubber-ringed chromed bottoms, using oft-exotic woods discovered in odd places (sweet-grained birch plywood from thrown-out flooring; vein-covered spalted pecan from a neighbor's storm-felled tree) or culled from sustainable-harvest scrap, e.g. a hash-marked black palm with an anti-corrosive stainless steel bottom, the same thing Jane Fonda miraculously maintained through the 1980s. Other items include turned-wood bowls (from mesquite, with a grain that results in a unique off-color rim edge), a sleek pepper mill (also from mesquite, with a rich red-brown color), and boxes with doweled/dovetailed/mitered joints, incorporating materials like bleached ash from a dining table and poplar from a headboard, likely tossed because the bed wasn't poplar enough.
Lucky'll also take custom orders, as well as design and construct chairs, tables, and cabinetry -- a hobby you might also consider taking up, when you find your construction site trick-turning is up to no wood.