Standing under the steel bones of what used to be part of Ridgway Elementary School, School District Superintendent Susan Lacy points out the classroom she taught in 20 years ago. It’s an empty space with a concrete slab floor.

The portion of Ridgway Elementary School built in 1972 has been stripped down to its metal skeleton as part of a roughly $18 million renovation slated for completion by the first day of school next year. For this year, officials have reconfigured the layout of the portio...