If I follow this right you're saying that standing straight up and down it will fit in the door but won't make the turn down the hall? Thats one huge couch or one narrow hallway... I assume you tried it both ways (back first and bottom first) when standing upright? Often times they will fit one way but not the other.
This was my point as well.
I guess there's no walkout basement so you can go down before you go up?