To cover cost overruns in school construction projects included in its $1.9 billion bond issue from three years ago, the Houston school board has voted to spend an additional $212.4 million.

KTRK-TV reports that the board vote will enable the district to cover the costs of dozens of new schools it promised voters in 2012. Several of those projects have exceeded original budget estimates.

District administrators say inflation is to blame for the higher costs; an internal audit questioned that finding, and the board has ordered a separate, external audit, which has not been completed.

Voters approved a $1.9 billion bond proposal in 2012 for construction and renovation of 40 schools.