So, the house was renovated without the "proper permit." 

Drafted a plan, gathered estimates, created a budget, put together DTI sheets, even got an "as-built" appraisal, and also have it in a permit status at the Local Building and safety office.Then I started to look into the construction loan and the permanent financing....to do it myself, and not through a builder.I soon realized that there are sooo many companies out there that want to try to help...but cant  (some of them were even on this network of people):  don't have builds on record, won't allow for owner-built homes, my credit is less than 680, while carrying the construction loan, there may be a point at the end where because i have my rental house while building that it become hard to pay, and  I can't pull out a private loan to help start process because my credit cards balances are horrible...and my "business" has no show of income.So, now we are here in the present time....   

If you wish, you can get a permit for your primary and not use it.

Also, if the Builder had to pull permits from the town, they may have had to show proof of insurance and that may be on file. 

Because they were a coffee cart, they were self permitted and didn't require anything from me but nice seating and wifi.

Unfortunately, my father did not pull permits when he built both properties 18 years ago.

And perhaps streamlining permitting/etc a bit.

I was able to negotiate a package that included the land, some of the materials, and the permits to build it.

A quick Google search shows a price of $30 - $50 per sq.ft. but I don't know if that includes the land, permits, utilities, and other incidentals. 

Tax Benefits While Building- Create an LLC and pay start up costs through the LLC (architect fees, permit fees, etc.).