There is some upside (low turnover, convert multiple units into one to create a new fair market regulated rent, etc.)

I was hoping to be able to find a way to prove it to them but I understand their regulations and looking out to protect against mortgage fraud.  

Such re-routing potentially creates problems with the state real estate regulations, with the IRS, with the state tax authorities, and/or with professional insurance. 

What sort of regulation is there on overnight rentals?  

This should be the link to explain the new rental criteria and regulations.

Is that a reference to regulation or permitting? 

They know it, they understand it, and they’re not constrained by the usual consumer regulations on residential loans so they can negotiate terms more creatively.By the same token, because there are more points of negotiation, it definitely pays to shop around and get competing bids for your loan business.

The rules and regulations are a real challenge.

State legislation enacted in 2017 led to an overhaul in the ways ADUs are regulated in the state, and made it easier for city planning departments to approve their construction.

How do you guys deal with the new Fannie Mae regulations?