Having leftover materials is a problem for almost every single construction project. And some local mandates are requiring builders to reduce construction-related waste.

Available in 15 markets, www.DiggersList.com is a free Web site for the construction industry, allowing users to buy, sell or trade excess materials and supplies; submit or respond to project bids; and more.

The Web site also offers the DiggersList widget. Users can embed the DiggersList widget on their own Web site to showcase the latest material they put up for sale. For an example of how it works, visit shophabitat.org/shophabitat and www.restoreoc.org.