We started with our guesthouse, an 850 sq ft space above our detached 3-car garage.  Went with traditional wood framing because it is what we knew and popular in the area. We used the smaller project of the guesthouse as a starter or learning project before we start the larger main house. We learned a lot this way and when we made mistakes the impact was less (like learning to not by sheet goods from the lumber yards... you can get them for less are the local hardware depot).  We will live on site in the guesthouse while we build the main house. To make the space feel larger we vaulted the entire ceiling and added a loft for the kids to play in. It cost more to build small but we're glad we did it. The second living space adds value to our estate and is a great place for guests or elderly parents.