The conditioned floor area shown on a real-estate listing is not the same as the surface that will be insulated or vacuumed. Attached garages, additions, vaulted rooms, low slopes, and inaccessible roof pockets can all change the usable attic area. A reliable Ajax estimate records the sections included and measures the depth or spray surface that the crew can actually reach.
That distinction also prevents over-scoping. If most insulation is clean and evenly distributed but one perimeter or addition is deficient, the plan can focus on correction and air sealing rather than selling a full replacement. Photos of the hatch, the open attic, and any problem area help establish this before an on-site visit.