Will a sofa of dimensions height 86 cm width 144cm and depth 94cm fit through my door which is 69 cm wide at it's narrowest with the door open?
There may be a way, but there are caveats. First off, I have never seen a couch that perfectly resembles a box or a crate, so there will be some points on the width or height that are probably not as wide as the strict HxWxD dimensions you give. Secondly, I have moved more than my fair share of couches, and I have used a trick to the process that might help. If there is a good bit of room on either side of the door on both sides of the wall, you can lift the couch and tip it up at an angle from the floor, much like you were lifting it from the back and leaving the front on the floor. This can make the couch a bit narrower than the width and depth dimensions you gave above. Then you can angle the lifted couch through the door along the "outside" wall, still holding it at the topped forward angle, put the wider arm through first, and then swing the couch out straight through the door to proceed. As you get to the other end, you would turn again along the "inside" wall to get the trailing couch arm through. However, if you have walls in the way, that may not work, such as a deep foyer. A friend and I had to abandon such an effort once, due to a long hallway that wouldn't let us swing the couch. It will depend on the length of the couch as compared to the wall face, how much swing room you have, and how much the actual arm of the couch sticks out based on its shape. Also, on some couches, there are legs attached to the bottom, often being screwed into the couch frame. If so, these type can be screwed off to give you a little more clearance through the door. Sometimes inches count. Good luck!