Outdoor Systems, Inc. (Outdoor) owns property in Cobb County on which an advertising sign is located. Because the parcel is put to no other use, the sign is considered “off-premises.” Cobb County adopted a Sign Ordinance which prohibited any new off-premises signs, but allowed existing ones to remain, subject to certain conditions. Section 134-346 of the ordinance permitted only minor maintenance and upkeep of nonconforming signs and provided that, when such a sign was destroyed or toppled by an Act of God, a variance would not be issued to re-erect it. After its sign was damaged in a tornado, Outdoor restored it. However, the County contended that Outdoor had made more than minor repairs, and revoked the permit, relying on § 134-346 of the ordinance. Outdoor appealed to the Cobb County Board of Zoning Appeals (BZA), which affirmed. It then appealed the revocation by petitioning the superior court for a writ of certiorari, and also sought a declaratory judgment as to the unconstitutionality .of the Sign Ordinance. The superior court granted summary judgment in favor of Cobb County as to all claims, and Outdoor appeals that order.
1. Outdoor contends that summary judgment was erroneous because § 134-346 conflicts with OCGA § 32-6-83 and is, therefore, void and unenforceable under Art. Ill, Sec. VI, Par. IV (a) of the Georgia Constitution. OCGA § 32-6-83 requires the payment of “just compensation” when a county acquires an owner’s property rights in a nonconforming outdoor advertising sign. The Sign Ordinance makes no provision for compensating the owners of óff-premises signs whose permits are revoked pursuant to § 134-346. However, Cobb County urges that we cannot address the constitutionality of its ordinance because Outdoor failed to raise that question before the BZA.
*607It is true that a challenge to the constitutionality of an ordinance cannot be mounted for the first time in the superior court. State Bd. of Equalization v. Trailer Train Co., 253 Ga. 449, 450 (320 SE2d 758) (1984). However, a more relaxed standard applies when raising the initial constitutional attack before the local zoning authority. Ashkouti v. City of Suwanee, 271 Ga. 154 (516 SE2d 785) (1999). Because the BZA cannot adjudicate a constitutional claim, and can only act legislatively, Outdoor’s challenge need not be as specific as that which it was required to make before the superior court. “[T]he requirement of notice is afforded to [the BZA] so that [it] may amend the zoning ordinance if it needs to be amended, not so [the BZA] can hold the ordinance constitutional or unconstitutional.” DeKalb County v. Bremby, 252 Ga. 510, 511 (2) (314 SE2d 900) (1984). The stricter standard for assertion of a constitutional challenge, set forth in O S Advertising Co. v. Rubin, 263 Ga. 761, 764 (3) (438 SE2d 907) (1994), continues to apply in a judicial forum, but it is “inapplicable in the legislative forum. [Cit.]” Ashkouti, supra at 156. The record in this case shows that Outdoor met the applicable less strenuous Ashkouti standard. In the hearing before the BZA, its counsel announced a challenge to the constitutionality of § 134-346 on numerous occasions, including the following:
[I]f you were to construe the ordinance as argued by the County, this ordinance would be unconstitutional; and, further, not only would the ordinance be unconstitutional, but the action, the governmental action of the County, would constitute a taking of property without payment of compensation.
This clearly gives the BZA “ ‘fair notice that a constitutional challenge is being raised.’ [Cit.]” Ashkouti, supra at 155. Outdoor informed the zoning authority of its contention that § 134-346 was unconstitutional and should be amended to provide just and adequate compensation for the taking of its property. “That is all that [Outdoor was] required to do. [Cit.]” Ashkouti, supra at 156. Thus, a sufficient attack on the constitutionality of the ordinance was raised in the BZA.
Moreover, in State v. Hartrampf, 273 Ga. 522, 523 (544 SE2d 130) (2001), which was decided just six months ago, we held that § 134-346 violates the Georgia Constitution because it “operates to create the situation prohibited by OCGA § 32-6-83; assuming that a sign has been damaged and, under the ordinance is in a condition so as not to be repaired, the ordinance effects its removal without compensation.” Here, Cobb County revoked Outdoor’s permit in reliance on § 134-346, contending that the sign, as the result of an Act of God, *608was in a condition such that repair was prohibited. Cobb County does not contend that, in revoking the permit under § 134-346, it paid Outdoor the compensation mandated by OCGA § 32-6-83. Thus, it effectuated a removal of the sign without the compensation mandated by state law. Under these circumstances, “application of the ordinance would violate the State Constitution. [Cit.]” Hartrampf, supra at 523-524.
Therefore, the dispositive issue is whether Cobb County can now rely upon an admittedly unconstitutional ordinance in defense of this appeal. Compare State Bd. of Equalization v. Trailer Train Co., supra. An appellate court must apply the law as it exists at the time of its judgment and may, therefore, even reverse a judgment that was correct at the time it was rendered, where, as here, the law has changed in the meantime and no vested rights are impaired. Fulton County v. Spratlin, 210 Ga. 447 (2) (80 SE2d 780) (1954). See also Osteen v. Osteen, 244 Ga. 445 (260 SE2d 321) (1979); Central of Ga. R. Co. v. Gwynes, 153 Ga. 606 (113 SE 183) (1922) (judicial notice in certiorari actions). Cobb had no vested right in enforcement of one of its ordinances which conflicts with OCGA § 32-6-83 and which is, therefore, unconstitutional. See generally Stauffer Chemical Co. v. Pop’s Top Shop, 140 Ga. App. 620 (231 SE2d 546) (1976). As to Outdoor’s constitutional challenge to § 134-346, the superior court erred in granting summary judgment in favor of Cobb County.
2. Remaining enumerations of error are moot.
Judgment reversed.
All the Justices concur, except Sears, P. J, Benham and Hines, JJ, who dissent.