Former schools chancellor Michelle Rhee’s decision to close 23 D.C. public schools in 2008 cost the city far more than previously reported, according to the District’s auditor.

The original $9.7 million price tag should have also included another $8 million that the city spent to move to demolish buildings, remove furnishings and transport displaced students, D.C. Auditor Yolanda Branche wrote in a recent report.

In addition, Branche wrote, the city forfeited $22 million in lost property value at the closed sites, bringing the total cost to about $40 million.

That news, first reported by the Washington Examiner, comes as current Schools Chancellor Kaya Henderson is in the midst of planning for another round of school closures, expected to be announced sometime this fall.

More than 40 District schools have fewer than 300 kids, and Henderson has said many times that DCPS can’t afford to continue operating so many half-full buildings. Closing schools, she has said, will allow the system to focus resources on providing more and better programs for students.

But critics have often challenged that claim, arguing that school closures carry hidden expenses that may tip the cost-benefit analysis — such as lost enrollment, which cost DCPS $5 million after the 2008 closures, according to a joint memo by the 21st Century Schools Fund, the Urban Institute and the Brookings Institution.

“You just can’t make the assumption that you’re going to save so much money,” said education advocate Cathy Reilly, executive director of SHAPPE (Senior High Alliance of Parents, Principals and Educators).

DCPS spokeswoman Melissa Salmanowitz said the school system has come a long way since the period covered by the audit — but will consider the report’s findings in the coming months while developing a plan for school closures.

“Lessons learned are always instructive,” she wrote. “We will continue to review the auditor’s findings and recommendations and incorporate them as appropriate with any future right sizing efforts.”