Zones, users and the questions that get asked
The first pass names each area the way staff already name it and records who uses it, how heavily and at what times. That produces the zone list. The questions are ordinary ones: how many people work here, when do visitors arrive, when is this room empty, who else has access. The answers matter more than measurements, because they determine frequency in a way that floor area does not.
A good walkthrough also asks what currently goes wrong. Which areas generate complaints, what the previous arrangement did poorly, what has been requested and refused. That information shapes the scope more usefully than anything observable, and a contractor who does not ask is building a proposal from the building alone rather than from the way it is actually used. It is also the fastest way to tell whether the person inspecting has done this before.
