There is code and then there is above and beyond, which is what a builder would do for himself. When I lived in Pensacola from '77 to '82, I acted as general contractor on two homes I built from my own plans. In Florida you don't need a contractor's license if you're going to live in the home yourself for one year. You also don't need an architect's seal on your plans unless it's commercial property. I had a residential designer draw up my plans and spec sheet for about $300 from my design.
In the panhandle they don't use masonry, it's all stick built just like Alabama. The local joke was we called Pensacola "LA", which stood for Lower Alabama. I used 6" exterior walls instead of 4" exterior walls. The cost was not much different since they are set on 24" centers instead of 18" centers. This allowed me to use 6" R19 batts instead of the normal R13 batts in the walls. Then I covered the outside with R2 insulfoam boards for a total of R21, except in the corners of the home I used plywood for strength. I also used a plastic vapor barrier, but before the drywall went up and I used up about 10 cans of spray insulation foam filling in all the corners, T's, bottom plates and top plates and around windows after the home was framed. Also insulated interior walls around bathrooms and laundry rooms and the wall between the garage and the house.
I also was able to do things that builders usually don't include or charge extra such as a central vacuum, five ceiling fans, a fireplace, a thrash compactor in the kitchen. Here's a view of the kitchen. I used Merillatt Cabinets which were above average, I got a good deal on the cabinets for $3500 and I designed it with a 10' breakfast bar.
Here's is the exterior. I did all the outside and inside painting. There are ways to save money, for example I didn't sod the yard, instead I used a 100 yards of sod and plug the entire yard and within six months I had a beautiful yard. I also kept every tree that wasn't in the way of the foundation of the home.
I'm disappointed with some of the features of TV homes. The push-pull valves I've had Kiley & Sons replace all of them, in fact they won't do any work it push-pull valves are in place. I've replaced the bathroom faucets. I've replaced the kitchen appliances, I had the carpeting removed from the dining room and had wood floors installed in the DR and Kitchen. I'm sure many of you have done the same. That 2600 sf home in Pensacola with a 2 car side entrance garage in 1979 cost me $52,000 to build, the lot was $15,000 and the pool was $8,000.