At the present time most people believe that you must be licensed by passing several test in order to become a builder. In many states small home builders are exempt and building for oneself is also exempt. However, just because you are allowed to build your own home does not make it a good idea to do so.
The record keeping involved will include accurate and up to date Insurance, inspections, permits, licenses, plans, banking and payment schedules and other items as they occur.
As you can see, unless you are experienced at this there are any number of things that can go wrong.
The reasons for failure of the project can be a combination of many things.
There are many stresses during construction which could result in failure of the relationship between the spouses or partners building the home.
Considering the many pitfalls of being your own builder you may want to consider hiring a professional.