Large underused or abandoned mall sites may be good candidates for reuse as green neighborhoods. Developers find them attractive because of their size.

This also makes them amenable to some more advanced and beneficial green features, such as district energy systems, low-impact stormwater management, and in some cases even site-scale wastewater systems with potential for reuse.

• Grayfields: Grayfields are older, economically obsolescent regional malls that are either empty or have low occupancy and low economic productivity.  They are a major potential asset: “Grayfields into Goldfields,” a 2001 study by PricewaterhouseCoopers and Congress for the New Urbanism y estimated that 7 percent of regional and sub-regional malls in the U.S. were grayfields and that a further 12 percent were approaching grayfield status.

• Brownfields: Brownfields are underused or abandoned industrial sites that may have been contaminated. Many resources are available from the U.S. Environmental Protection Agency and others to assist in the complex matter of redeveloping these sites.

Belmar: Located in Lakewood, Colorado, Belmar is a good example of grayfield redevelopment that was led by a developer and facilitated by the local government.  A 106-acre former mall, it has been redeveloped into an award-winning, transit-oriented neighborhood with retail shops, housing, offices, and other uses.

Stapleton: Stapleton is an award-winning, master-planned community on a former airport site outside Denver, Colorado.  Designed as a sustainable community, it will accommodate 12,000 homes and 13 million square feet of commercial space over the next 15 years.

In the broader context, communities should consider how much industrial land should be kept for the long-term. Many goods sold in the United States today are made overseas, but this could change with a rise in oil prices – and therefore transportation costs.