ARI is for Solar.
Solar array design and installation depends on accurate drawings to maximize solar yield. Roof obstacles such as vents, gas lines, A/C units, and exhaust fans will determine where panels can go. Walls and parapets, RTU's and other objects may cast shadows, so you'll need to know their height. Roof slope and aggregate size will affect installation.
Have ARI survey your roof for an accurate As-Built that will include every detail.