Luke 2:7 and she gave birth to her firstborn, a son. She wrapped him in cloths and placed him in a manger, because there was no guest room available for them.
This is the way God found to come and live in a house on earth. He allowed His Son to come to earth and be born in Human form to live amongst us.
God became flesh so He could be here with us and show us how much He loves us.
Even then, His first day on earth was not in a nice house decorated for His birth, but in a stable alongside animals.
Even Jesus did not require a mansion to live in!