Here is a list of Democrats opposing Americans with Disabilities Act

[Kaleva]

83. Many businesses think there is a grandfather clause but that's no longer true

"When the first ADA standards were introduced in 1991, existing small businesses and some public buildings were allowed to avoid complying unless they added new construction or renovated their properties. In 2010, the updated regulations removed the “grandfather clause.” While you didn't have to instantly meet the 2010 standard, your property did have to meet the 1991 regulation.

The “Safe Harbor Rule” requires compliance

Meeting only the 1991 standard is called the Safe Harbor" rule. As the 2010 regulations rolled out new requirements for new structures, parking lots, and even sidewalks, your established business is only required to upgrade to the 2010 standard if you undergo renovations. However, the person filing a drive-by lawsuit probably doesn't know or care if you are legally in compliance with either standard. "

https://www.karlinlaw.com/blog/2017/08/what-is-the-grandfather-clause-re-ada-compliance.shtml

"The ADA does not have a provision to "grandfather" a facility but it does have a provision called “safe harbor” in the revised ADA regulations for businesses and state and local governments. A "safe harbor" means that you do not have to make modifications to elements in an existing building that comply with the 1991 Standards, even if the new 2010 Standards have different requirements for them. This provision is applied on an element-by-element basis. However, if you choose to alter elements that were in compliance with the 1991 Standards, the safe harbor no longer applies so the altered elements must comply with the 2010 ADA Standards.

A “safe harbor” does not apply to elements that were NOT addressed in the original 1991 Standards but ARE addressed in the 2010 ADA Standards. These elements include recreation facilities such as swimming pools, play areas, exercise machines, miniature golf facilities, and bowling alleys. On or after March 15, 2012, public accommodations must remove architectural barriers to these elements listed above are subject to the new requirements in the 2010 Standards when it is readily achievable to do so."

https://adata.org/faq/my-building-grandfathered-under-older-ada-standards-or-do-i-need-comply-new-2010-ada-standards