Well, I'm no Bob Vila, but, I did design, draw up the plans for, and build (with my wife"s help) a 1650 sq.ft. living space, 1024 sq. ft garage, & 360 sq.ft. woodworking shop addition to my primary home. The two of us did everything (well, most everything) from digging & pouring the footers up.
We did have help putting the trusses up, and I hired the shingles out. I also hired the drywall on the ceilings out. (I did the walls)
We did all the trim work.
I put ceramic tile in the bathrooms & kitchen & hardwood in my bar. I also installed all the cabinets in the bar.
We did everything else including the wiring & plumbing.
We also added a four layer deck on the back of the house.
Neither of of had ever built anything before we started on this project & it was a little intimidating, but we did it & it came out beautiful.