I didn’t see their FB ad, I stumbled upon their Craigslist ad a while back. 

I would suggest checking with your Planning & Zoning office to find out what modifications you might need to make because of Fire Code, ADA, etc. 

If they have not confirmed an hour prior to their appointment, I send this text to their phone (which was required as part of their contact information I required in the response to my ad):As I had requested in my email, you have not yet confirmed your apartment showing for this evening, scheduled for 7:00pm.

I could imagine that being a nice booking feature, especially in an area where you get multiple couples traveling together.Also consider building it for ADA and easy access.

I plan to target the 55+ community so I would like them to be a one level rancher with ADA sized doorways etc. 

.$250 non refundable, $50/mo per pet.Keep in mind those ADA laws.

Would you have to make the unit ADA compliant i.e. grab bars in the bathroom, a lower toilet? 

The rules and consequences around violations of ADA or FHA are strict and severe.  

Are your homes accessible for elderly, if not you will have to go through a checklist to make accessible (not ADA but almost up to that standard.)

Do you need to add additional entrances for egress, sprinklers, windows, ADA compliance, fireproofing between floors etc.