You might consider approaching larger banks for a HELOC on an investment property, as most smaller banks and credit unions typically lend only on primary residences.

I own a cleaning company and was going to offer insite. 

Anyways, we had someone make an offer on our property that would get us out of the deal and breaking even.

We have fixed mortgages that can be amortized for 30 years, but typically can only lock them in for 5 years maximum.

There are many great neighborhoods that offer a consistent predictable ROI.

You can accept the no personal guarantee but counter with a slightly elevated lease amount, then offer he choice; lower amount with guarantee, higher without  

I have heard good things about KBKG and they have an online tool for cost basis of 600k and under https://www.kbkg.com/residential-costsegregator I personally used CSSI and they were awesome https://costsegregationservices.com/ but don't offer DIY.Hope that helps!

You were kind to offer extra pay for holidays.

Never heard of them before....but your typical real estate "mentoring" guru will invite you to a free 2-3 hour session, and convince you to come to all day on Saturday or 3 day weekend course for $299-$399, when you are at that course, they'll convince you to be a Big Dog player for full on mentoring at $15,000-$50,000.   

Doing the right thing is expensive, but it pays off in the end.Yes, this is the option I initially explored and came across this pilot program that NYC was offering specifically to help homeowners legalize basement/cellar apartments but it seems like the pilot program was not much of a success.