The Fulton County Board of Education has taken another step toward the replacement of Riverwood High School in Sandy Springs.

The board on Thursday approved site and floor plans for phase one of the project, a three-level, 116,000-square-foot addition of 26 “instructional units” including classrooms, science labs, teacher planning areas and other support facilities. The first phase also includes demolition of the adjacent Heards Ferry Elementary School building, relocating the baseball field and a new entry drive.

The $28.6 million project is set for completion in the summer of 2017. Architectural drawings have been developed for phase two, but there’s no word on when that work would begin. School officials say it’s contingent on future funding.