[josh3736]

The answer is "it depends" on the particular city, county, and/or state.

Florida is a little unusual in that state law makes a very wide range of information public and easy to get. In this case, the town has actually posted all the relevant documents on their website (https://www.townofsurfsidefl.gov/departments-services/town-c...), so you can just click that link to get the plans.

Other places have varying levels of access to building documents. In SF, for example, DBI maintains plans and other documents, but state law prohibits reproduction without the property owner's consent. A member of the public can, however, make an appointment to view the plans in the DBI office. (https://sfdbi.org/DOP)

But generally, yes, all buildings' plans are maintained by (usually) the county-level office that issues permits.

[politelemon]

Thanks so much. That was useful to learn.