I found this guide http://www.ada.gov/restripe.pdfBut not sure if it's up to date, i want to ensure my parking lot is ADA compliant, is there a more up to date guide for California?

Also perhaps consider increasing the rent slightly to cover for any contingencies and agree to return the excess upon compliance with lease and vacant possession as long as it is all state compliant. 

My main interests are for low cost insulators for non-residential applications, but if I can integrate micro rebar or other enhancements and achieve a code compliant (by PSI compression test) formula, then it's a matter of finding a PE to sign off on a floor, foundation or wall application.

Generally speaking, they can point you in the right direction and answer questions to ensure that you remain compliant with 1031 guidelines. 

What is most interesting about this deal is that the property used to be a hospital before it was converted to an apartment complex 30 years ago, so it is already equipped with many ADA compliant amenities such as large doorways/hallways, elevator, etc.

We converted property to 2 legal units which brought in an extra $1200/ month in rental income and is compliant.

*ps I know LLC setup isn't really $1k, but since OZ slightly more tricky I leave some buffer for legal/tax consulting, QOF/OZ compliant Op agreements, etc. in the "setup" costs.

@Jonathan R McLaughlin hit the correct answer (at least the one I have run into before).It can be a pain because use has to pre-date when the zoning made it non-compliant.

It's compliant with the law. 

I have seen a retrofitted single family home with a zoning change, which did require ADA compliant modifications; the same was not true for a large single family home with traditional zoning being operated similarly).