Luke 2:7 translates "kataluma" as "inn". But in Luke 22:11 the same word is used for what seems to be a personal residence:
11 And ye shall say unto the goodman of the house, The Master saith unto thee, Where is the guestchamber, where I shall eat the passover with my disciples?
Mark 14:14 is similar.
I was reading some internet thing about this, and it basically said, the guest bedroom was full, so they were staying in the homeowner's main room. Most people had 1 or 2 room houses with an unattached guest quarters. People kept their animals inside (the main room), at least at night, hence the manger. So, they were with relatives who were actually being quite hospitable.
Which it paints a different picture than "the hotel was full so they slept in a cave (or barn)"
Also there was another word in use for "hotel". If I remember correctly it appears in the Good Samaritan story.
So in Luke 2:7, is it an inn or a house?