Whether a freezer fits depends on its external size, the ventilation clearance and the room for the door to open, not on its internal volume. The condenser rejects heat from the back, sides or top; a unit pushed against a wall or into a corner cannot, so it runs longer and uses more energy. The clearances, and the space needed for service, are given in the model's installation manual and differ from model to model.
Where the unit stands matters for the same reason. Under EU Regulation 2015/1095, a light-duty professional cabinet (climate class 3) is one that can hold temperature only in a 25 °C room; class 4 is 30 °C and heavy-duty class 5 is 40 °C. Check the class of any unit that will stand beside an oven, a dishwasher or a sunny window.
Route and floor
Compare door width, corridor turns, the lift car and threshold height with the packed dimensions of the unit; the narrowest point decides. A full deep freezer is heavy, so settle the floor capacity with the building contact before it goes on a mezzanine.
Before ordering, mark the footprint, the ventilation clearance and the door swing on the floor with tape and leave it for a day. You will see how often people cross that space and how drawers and shelves can be reached.