If something is built according to standards at the time, that should make the property owner safe even if the rules change.

So if you do build that ramp 4 years ago only to have the standards change two years down the road, the building code would recognize this as a “legal, non-conforming” ramp.

Taken to a more extreme example, imagine you build your dream home with side and front setbacks that are within the law. A few years later, the setbacks are increased resulting in your home being across the new setback lines.

You don’t have to tear down the home and rebuild it so why should the ramp have to be torn down and rebuilt?

Most jurisdictions in which I have lived say you don’t have to bring the non-conforming structure into compliance until you go to replace a certain percentage of the structure itself. So if the code states that a 50% refurbishment is considered “new,” when you replace 50% of the structure, you have to bring it into compliance with the new codes.

There is nothing that could or should prevent the ADA as a building code being applied in a similar manner.

Using the example of the ramp above, imagine if you had put in a (then-) ADA- compliant ramp four years earlier (under threat of fines), only to find the ADA standards had changed two years later–when you get sued again to force compliance under the “current” standards, which forces you to rebuild/modify the ramp….then the ADA standards change again in three more years, requiring something else to get modified/changed (again under threat of more lawsuits / fines), and so on.

Should there be limits on something like that, so the business or public building can break that cycle of build/get sued (ticketed)/fix/get sued later/etc.?