Checks whether a piece fits the space, including the walkway you need to leave around it.
Formula
remaining space = room dimension - item dimension - walkway x sides; delivery check compares the largest item dimension against the narrowest door or stair width
Assumptions
All values in the same unit, measured at the narrowest point including skirting boards, radiators and door handles.
Packaging is usually larger than the item. Check the boxed dimensions for the delivery route.
Limits
Measure the real route, including turns on a landing. A width that fits a door may not turn a corner.