A LAW on the books in the District since the mid-1990s gives charter schools first priority to vacated public school buildings. Sadly, that hasn’t prevented city officials from hoarding the properties, selling them off to private interests or, most appalling, letting them rot while deserving charter schools scrounge for space or turn students away. So the decision by Mayor Vincent C. Gray (D) to make more room for the District’s growing charter sector is an encouraging, albeit overdue, step forward.

Mr. Gray announced Monday that 16 former or soon-to-be-closed public schools will be made available for reuse by charter schools and other community groups. Long-term leases will be made available for 12 schools; the others will be subject to short-term rentals. Included are eight of 15 schools that are slated to be closed by June 2014 but — much to the dismay of advocates for charter schools — were going to be mothballed instead of earmarked for reuse.

“We’re pleased. This is a large number of buildings,” Robert Cane, executive director of Friends of Choice in Urban Schools, told The Post’s Emma Brown.

Charter schools currently enroll 43 percent of public school students, but the lack of suitable and affordable facilities has been a chronic issue. It simply made no sense to see charters, including those with strong academic programs, operating out of makeshift facilities, forced to limit enrollment and unable to expand while prime education real estate went underutilized. The Public Charter School Board has a waiting list of 22,000 applications, up from 17,000 last year. One top-performing charter school, Two Rivers, had 1,840 applicants for 32 places.

Deputy Mayor for Education Abigail Smith, who played a crucial role in formulating the new policy, will oversee disposition of the properties, and academic performance appropriately will be an important part of the criteria. Hopefully that will mean high-performing KIPP DC will finally find a new home for its high school (Washington Post Co. chief executive Donald E. Graham serves on KIPP DC’s board of trustees) and other similarly qualified charters will be able to serve more children in search of better schooling.