Thought we had a case of adult son mooching of of mom.

Occupants include adults and children of any age.As far as any advertising is concerned, are there specific reasons why you are considering stating maximum occupants for your rental?

Renting space to Adult Day care provider?

It is no longer needed as an office, so the extra adult could sleep there.I suppose the HUD rule would allow it, but I still think that its asking for trouble. 

SEC 8 REALITIES SEC 8 tenants have to have a job unless they are disabled.No adult on the SEC 8 lease can have a drug or felony conviction.When a SEC 8 tenant gives their landlord notice that they plan to move, SEC 8 sends a form to the current landlord giving them 10 days to respond saying the tenant is or is not in compliance with their lease – IE – owe any money for rent or repairs.

I know someone who does this in Austin with adult professionals and has a great system on multiple leases. 

Renting to college students will require more work than renting to a family or a couple adults that understand how to adult.

Many areas will have special regulations around unrelated adults living together (aka student housing) so you should research your local regs to see what you need to comply with from a code standpoint.Also yes, make sure you understand federal fair housing laws and don't break any of those in your advertising or leasing.

Most of them have decades of work experience and experience as an adult.

I grew up in San Diego, but have spent most of my adult life in Boise.