The Four Measurements You Need
First: your room's usable length and width (subtract built-in cabinets, TV units, and door swing arcs). Second: the sofa's external dimensions — width (arm to arm), depth (front to back), and height (floor to top of back). Third: the delivery path — lift internal dimensions, stairwell width at the tightest landing, and apartment entrance door width. Fourth: visual proportion — the sofa width should ideally match within 30 cm of the room's shorter axis, or the room will feel unbalanced.