With all the changes in the economy and all the new construction builders out of work, the builders have had to enter into the home improvement business searching for work. This brings may well intended but inexperience contractors into this specialized business. New construction is a different form of building compare to working with older buildings which requires overcoming pre-existing conditions.
Meaning that new construction builders are working with straight foundations which are plumb and level, so the start of the process is going to be easier to work with in most cases. I do understand that some of the new construction buildings can be very complicated and I'm not saying that skills need to build a new house are any less complicated, only that older building are not plumb and level or square because they have settled over time.
This does required a certain amount of experience to overcome these special circumstances. Like put a door into a crooked opening or installing kitchen cabinets to walls that is not plumb or level.
Tell us all about your home improvement experiences.