Have done an extremely extensive full gut remodel (practically brand new home, literally everything updated/repaired from foundation, roof, windows, all exterior work, LVL beams to demo load bearing walls and create open layout, med to high end bathroom/kitchen renovations (master shower is floor to ceiling tiled in w/ double rain shower and ADA compliant, granite countertops, 6-8 person island, all new stainless appliances), all new electrical wiring, plumbing, etc., solid core doors, widened old 22' door openings to 24', new laminate wood flooring throughout, 5/8' baseboards/trim throughout, tankless water heater, tape/bed/texture/new paint on all new drywall), etc.I'd love to hold onto the property as I have no compelling event forcing a sale. 

ADA CERTIFIED, first thing on any commercial property and ask around could be certified but still a quake very few are good in this area4-Expecially if commercial again- but also usefull sfh  thermal imaging camera, .oisture meter, and underground sonar water leack detection ew   we are talking a ten k investment but some to cheap to pay for, same to you you get what you pay for. 

If this property is historical in the sense that it is on or may be placed on a historical register, the renovation project will also have to conform to a set of conditions that will generally have to do with maintaining all or significant portions of existing architectural elements such as facades, building materials and colors.Historical or not, any planned project will have to be heavily vetted in terms of existing conditions and projected uses for all major building elements such as structural, electrical, plumbing, mechanical and ADA and ANSI provisions.

Decided to try what @Wayne Snyder suggested for Ada County, The county assessor website does provide gis files for all parcel within the county as well as unit counts for each one.

Also, an I'm only speculating here, unless the unit(s) are ADA accessible you might not need to provide an accessible route. 

I plan to make a unit ADA compliant.

I also think most landlords don't realize that ESAs are not covered by the ADA, only Fair Housing, and that the landlord does have the right with service animals, if the disability and need are not readily apparent (i.e. a seeing-eye dog), to ask the specific function of the animal and documentation that the animal is a medical necessity.

@William Coet there are a variety of reasons at play and interestingly enough for the past 2 years or so I am getting $700k per SFH partially because they changed some of the regulations specifically for people with developmental disabilities where they now want the SFH to have Fire Suppression systems and sprinklers as well as ADA requirements.There was a few lawsuits in NJ that have really helped make affordable housing possible.

https://www.idahostatesman.com/news/local/community/west-ada/article231044388.htmlCaldwell approves 187-home subdivision.

ADA height and elongated.