Please reference HUD Guidance Memo 2013-01.Also, as someone is bound to make the mistake in this thread and quote the ADA, Americans with Disabities Act....that is a law that governs public accommodations, (things like hotels, restraunts, airports)....the ADA has zero to do with residential real estate.

I believe all states have provisions for terminating a residential lease, examples include (but not limited to) a tenant called to active military duty or change in orders, the death of a tenant (releasing the estate) or of a co-tenant, medical conditions requiring special care or residential amenities, another situation could include ADA compliance after a life changing event. 

My main concern is ADA/ABA regulations for accessibility. 

But not sure if the land is big enough to build a senior care facility considering it might access for an ambulance, ramps, bigger rooms, ADA accessible etc. 

I own a second floor condo in an apartment complex that was moved to condos strictly because it doesn't (and CAN'T) meet the new ADA requirements for first floor units. 

Does the profit from selling a property with a 1031 exchange affect income requirements of the ACA/ Obamacare?

Check out any ADA concernsSend some pics.

And would it have to be installed by another type of specialist rather than our contractor (due to liability/ADA considerations)?

A ground level (slab) addition, separate bedroom, living room and elder friendly bath.Then share the kitchen and dining room.You could make the doorways and bath ADA compliant for wheelchairs, and ground level because elders sometimes have issues with stairs.Then when you sell, demo the interior walls and make it into a nice patio.Basically build a patio and convert it into a demi-apartment with easily removable walls.Good Luck! 

Although it had some weird ADA alterations that were made to it, it made perfect sense to close on.