Write a letter to the tenant to be clear of this point - that no additional modifications are allowed.  

Also, are there other modifications besides the shower that tenant might ask for in the future beyond the shower?

Any modification needs to pre-approved in writing with a clear definition of who is paying what.

If you can pass the zoning, the modifications to bring an existing building up to code can be extensive and expensive.

It's an important part of the story, vital IMO, and it will have it's affect on real estate too.So then the question becomes, the one we are all trying to answer, how does one respond rationally to an irrational world?

I've started hearing a little bit about rate increases for homeowners who used the government's Home Affordable Modification Program (HAMP) loan modifications beginning in 2009 (5 years ago). 

@Kayla Truong The housing authority/tenant are asking for a modification of the lease of which you are not required to do. 

I'd like to learn how to find operators, how much to charge, length of rent, modifications/conversion, liability, structure contracts, utilize consultants, and more. 

I was worried they may be aware of some vital details I may have missed on my first walk though.Thanks again for your time.

Modification is in the best interest for lenders for this region.