Here are some initial thoughts..For any particular building, you are going to want to reach out to the city about zoning, fire proofing, ADA compliant, sound proofing, parking, egress, previously permitted work etc..  

You said it yourself, "Disabled Veteran" now you have to follow ADA & Fair Housing.

This issue is important for landlords to call their Congress person to draft or support bills that treat those with ADA needs in clear ways and those who fake the system to be discouraged.

., found a mixed use (residential and commercial/medical) 3/2 unit in northern Milwaukie (ADA accessible, x ray viewers, etc.) in nice little street.

The next easiest will be in the county area (canyon and ada), but you will need to be looking at larger properties. 

Any ADA design recommendations or resources would be appreciated.

We bought the home in 2021 with the intention to clear the lot so my grandparents could build an ADA accessible home.

First one was that we might not be ADA compliant, and wouldn't it be a shame if someone were to sue because of that?

Does the Americans with Disabilities Act (ADA) require any modifications to existing structure to make it accessable. 

I’m a little clueless on what needs to be done to comply with ADA in the process of the renovation.