Defenses or claims based in equity have long been recognized by Pennsylvania courts in zoning and other land use matters. There are three main equitable theories, all of which bar a municipality from enforcing its land use regulations and permit property owners to continue a use or activity in violation of applicable ordinances—equitable estoppel, vested rights and variance by estoppel. Pennsylvania courts consider all three theories unusual remedies that should only be granted in the most extraordinary of circumstances, as in Lamar Advantage GP v. Zoning Hearing Board of Adjustment, 997 A.2d 423 (Pa. Commw. Ct. 2010). These three theories are closely related and the elements of each vary only subtly.

Equitable Estoppel

The doctrine of equitable estoppel applies when:

• The municipality intentionally or negligently misrepresented a material fact;

• The municipality knew or had reason to know that the property owner would justifiably rely on the misrepresentation; and

• The misrepresentation induced the property owner to act to his detriment because of his justifiable reliance, as in Cicchiello v. Bloomsburg Zoning Hearing Board, 617 A.2d 835, 837 (1992).

The Commonwealth Court has consistently held that the theory of equitable estoppel cannot be relied upon to provide relief when the property owner asserting it “knew or should have known that the alleged promisor was without authority to effectuate the alleged promise,” as in DiSanto v. Board of Commissioners, 172 A.3d 139 (Pa. Commw. Ct. 2017). For example, a property owner cannot reasonably rely on the statement of an appointed official when the property owner knew, or should have known, that the official does not have the authority to bind the municipality with his statements. See, e.g., Strunk v. Zoning Hearing Board of Upper Milford Township, 684 A.2d 682, 685 (Pa. Commw. Ct. 1996) (landowners could not justifiably rely on a zoning officer's statements regarding the adequacy of a sewage disposal system where the zoning officer expressly directed landowners to the sewage enforcement officer before proceeding).

Vested Rights

The vested rights doctrine permits a property owner to use his property in a manner contradictory to applicable zoning regulations where a permit is issued in error by the municipality.  In order to prove the existence of a vested right, a property owner must show:

• His due diligence in attempting to comply with the law;

• His good faith throughout the proceedings;

• The expenditure of substantial unrecoverable funds;

• The expiration of the permit appeal period with no appeal; and

• Neither individual property rights nor the public health, safety or welfare will be adversely affected by the use or activity authorized by the permit, as in Petrosky v. Zoning Hearing Board, 402 A.2d 1385, 1387 (Pa. 1979).

In Petrosky, a township issued zoning, building and use permits for the construction of a garage on land that the Petroskys had an option to purchase. Upon receipt of the permits, the Petroskys purchased the land and constructed the garage, expending more than $15,000. During construction, the township's inspector visited the property three times and at no point informed the Petroskys that a problem existed. Approximately seven months after the garage was completed, the township realized that it had erred by allowing construction within the minimum required setback. The township subsequently revoked the Petroskys' permits and ordered the garage to be removed or relocated in compliance with the zoning ordinance. Based on the foregoing, and the lack of any evidence in the record that the Petroskys' reliance on the permit was in bad faith, the court concluded that they had acquired a vested right and were entitled to continue using the garage as-is, even though the setbacks were considerably less than required by the township's zoning ordinance.

Similarly, the Commonwealth Court determined it was inequitable to enforce applicable zoning regulations against a property owner in Three Rivers Youth v. Zoning Board of Adjustment for Pittsburgh, 437 A.2d 1064 (Pa. Commw. Ct. 1981). There, the city's zoning officer erroneously issued a building permit for the construction of an office building in a residential district (i.e., a use that violated the city's zoning ordinance), there was no evidence in the record to indicate the property owner's reliance on the permit was not in good faith, and the city acquiesced to the obvious commercial use of the property for seven years before taking action to remediate the violation.

Variance by Estoppel

The theory of vested rights applies where a municipality issues a permit in error. In instances where a permit has not been issued, a property owner may be able to assert a defense to an enforcement action based on the theory of variance by estoppel, the elements of which are:

• There was a long period of time during which the municipality knew or should have known of an ordinance violation, but failed to enforce the implicated ordinance;

• The municipality actively acquiesced to the illegal use/activity;

• The property owner acted in good faith and relied innocently upon the validity of the use or activity throughout the proceedings;

• The property owner made substantial expenditures in reliance upon their belief that the subject use or activity was permitted; and

• The denial of the variance would impose an unnecessary hardship on the property owner, as in Skarvelis v. Zoning Hearing Board of Dormont, 679 A.2d 278, 281 (Pa. Commw. Ct. 1996).

In analyzing the theory of variance by estoppel, the Pennsylvania Commonwealth Court has stressed that the mere passage of time does not, in and of itself, entitle a property owner to such relief. Moreover, the court has held that a property owner has a duty to check a property's zoning status, and failure to do so undermines the property owner's argument that he relied innocently and in good faith on the legality of the particular use or activity.

Municipal action or inaction triggering a property owner's right to relief from ordinance enforcement often embodies elements of more than one of these three equitable doctrines (e.g., municipal inaction coupled with the issuance of a permit or the negligent misrepresentation of a material fact). As a result, the rigid labels given to the various theories often cause confusion for zoning hearing boards and the courts alike. However, in the majority of instances where Pennsylvania courts have granted equitable relief in a zoning or other land use dispute, the municipalities have done more than passively stand by while an illegal use or activity occurs. Typically, they have taken an affirmative action, such as granting a permit or making a representation or statement, which has reasonably led the property owner to conclude that the use or activity authorized thereby was permitted, and then waited years to take action against the property owner for the violation.