In Town of Bozrah v. Chmurynski, No. SC 18424 (Feb. 14, 2012), the Connecticut Supreme Court held that in order for the town's zoning enforcement officer to inspect private property, he must obtain an injunction (similar to a warrant in the criminal context) that is based on probable cause:
In conclusion, we hold that a zoning official may inspect a single property—not part of a routine or area wide search—pursuant to § 8-12 if the zoning official first obtains an injunction issued upon probable cause by a judicial officer as articulated in this opinion. Because the trial court failed to make a preliminary determination of probable cause to believe that a zoning violation existed on the property, its order permitting a search of the defendants’ property violates the fourth amendment.
Slip op. at 13. The opinion also set out the criteria that a court must consider when it determines whether to issue the injunction.
More here, from Patty Salkin's Law of the Land blog.