Would you have this case, in which renters who had built illegal structures argued (with initial success) that the landlord had to eat the code enforcement violations they created and couldn't tear down their iillegal structures or terminate their leases.
Recreational vehicle parks get more pads per acre than traditional subdivisions would (at least they used to in the Keys). A few parks in the Keys had deals where folks could basically rent the pads year to year with renewal rights - originally folks up further north used them as weekend (if from Miaim-Palm Beach) or winter (if from snowy climes) places to park their campers. Over time folks just moved in big motor homes and started building porches, garages, and Tiki huts (ONLY in the Keys) etc., on them. Through the late 70's and early 80's this seemed like a pretty efficient way for the non-rich to enjoy a winter home in the Keys.
Bring in two big changes: economics - the park gets really valuable as development land if only the new owners can get rid of all these campers; and growth management - eventually Monroe County realizes it has a zoning problem and starts code enforcement actions against the park for the unlawful buildings.
So the new park owner tries to terminate the year-to-year leases on renewal for creating violations and the offending renters take them to court, arguing that because the old owner turned a blind eye, the new owner was basically estopped from enforcing the building code against them, even if the park owner was being fined.
What's amazing to me is that the case ends up turning not on the clear question of whether a landlord always has the right to demand that tenants not violate zoning regulations, but instead on waiver and estoppel arguments construing the renewal rights to the leases and the right to require compliance with the County codes via a requirement to follow Park rules. The Court ends up finding that the landlord could force them to leave based on non-compliance with the Zoning Code, but you really wonder why it would ever have to go that far :)