PER CURIAM.

Plaintiffs Keith and Liesel Fernandez appeal from a July 16, 2008 order dismissing their complaint seeking to set aside a stop construction notice issued by the Township of Bloomfield and challenging the Township Zoning Board of Adjustment's decision denying their variance application. We affirm.

I

Plaintiffs' house is located in a neighborhood of small homes, built relatively close to each other, on small irregular-shaped lots. Plaintiffs applied for and obtained a zoning permit on March 21, 2006, and a construction permit on May 9, 2006, to add a second floor bedroom to their house. With the approval of the municipal building inspector, they began construction, which included columns to support the new bedroom. However, a few weeks later, on June 23, 2006, the Township zoning officer issued a stop construction order, asserting that the project did not meet the bulk and setback requirements of the local zoning ordinance. Plaintiffs applied for variances, which the Zoning Board denied after a two-day public hearing.

The following pertinent evidence was introduced at the Board hearing. Plaintiffs' expert, Roger DeNiscia, a licensed professional planner, testified that plaintiffs' residence was located on an irregular-shaped lot, which constituted "an unusual, or unique condition." The irregular-shaped lot resulted in "varied," "totally different" setbacks, which "makes it very difficult to develop" the property. DeNiscia "concluded that it's only because of the size of the lot and its shape that create[d] the need for a variance." He also opined that granting the variance would not block the sunlight available to neighboring houses or otherwise have a negative effect on the surrounding properties. Therefore, he reasoned that the Municipal Land Use Law, N.J.S.A. 40:55D-1 to -163, authorized the Board to grant a variance. However, he admitted that if he had been asked to design the addition, he might have been able to design a structure that conformed to the zoning ordinance.1

The objectors' expert, Karen Rosenberger, a professional planner, challenged DeNiscia's assessment of the uniqueness of plaintiffs' lot. Rosenberger testified that the lots in that zone "are all small, undersized, irregular lots" and, therefore, "the light and space and air for all of these people is compromised by what happens on adjacent property." Rosenberger added that the addition does not fit "within the context of the neighborhood." Based on these and other factors,2 Rosenberger concluded that plaintiffs did not present "a viable proposal."

The application was also the subject of vociferous opposition from many of plaintiffs' neighbors. One of the neighbors testified that he "used to be able to go into [his] backyard and look up and see the sky. Now, [he] see[s] what looks like a ski lodge." Plaintiffs' rear neighbor testified that the addition compromised the "little privacy" afforded to residents in the zone. The neighbor described the addition as "a watch tower, peering [into] the nearby houses, imposing on everyone's privacy." Other residents echoed these sentiments, and added that the addition did not conform "with the character of the houses in the neighborhood." They also complained that the addition overshadowed their back yards and blocked their views of the neighborhood. One neighbor testified that the addition blocked the sun in such a way as to limit the hours during which he could use the pool in his back yard.

Following the public hearings, the Board denied the application. The Board noted that plaintiffs' residence was located on an "irregular lot" and that construction of the addition was "substantially completed" when the Township issued the stop construction notice. The Board, however, denied the application, based on its conclusion that the "addition would be a substantial detriment to the public good because . . . it denies neighboring property owners adequate light, air and open space." The Board also determined that the "addition would invade the privacy of neighboring property owners."

The Board based its legal conclusions on its factual findings that "the addition hovers over the rear yard of the adjoining property to the west" and "affords a view of the rear yard of the adjoining property to the east," both of which are conditions that "did not exist prior to the construction of the addition." The Board relied in part on photographs of the addition and the surrounding neighborhood.3 Ultimately, the Board ruled that although plaintiffs "may meet the positive criteria due to the irregular shape of their lot, they cannot meet the negative criteria due to the substantial detriment to the public good resulting from the addition." The Board also concluded that "[t]he negative impact of the addition far outweighs any positive impact."

Before the Law Division, plaintiffs contended that the Board was equitably estopped from denying their variance application, and that the denial was arbitrary and capricious. In a thorough oral opinion issued May 16, 2008, Judge Giles disagreed.

Addressing the estoppel issue, Judge Giles first rejected plaintiffs' argument that any zoning violation was de minimis, finding that "the dimensions of the addition existing in the plan submitted to the Township, the surveys before and after construction, and the photographs marked into evidence showing various stages of construction clearly show that the side, rear and bulk deviations from the zoning ordinance are not `de minimis.'" Judge Giles further concluded the Township's zoning ordinance was "plain and unambiguous and required no interpretation and was not the subject of any debate as to interpretation when the permits were issued or at any time." In other words, there was no arguable legal basis to issue the zoning permit. Judge Giles further found that the Township, "rather than sitting back and doing nothing," proactively inspected the addition to determine whether it violated the zoning ordinance. Relying on photographs of the addition, Judge Giles also found that plaintiffs completed construction of the addition after receiving the stop construction notice.4

Next, Judge Giles upheld the Board's denial of the variance application. He found substantial support in the record for the Board's conclusion that plaintiffs failed to meet the negative criteria, which were required to obtain the requested (c) variance. See N.J.S.A. 40:55D-70(c) and (d). Judge Giles cited testimony from the neighbors that the addition affected their sunlight, air and privacy, finding that the neighbors' complaints were supported by photographs in the record.5

He further concluded that there was nothing unique about plaintiffs' property when compared to most of the other properties in the neighborhood. Hence, he observed that plaintiffs also did not satisfy the positive criteria.

II

The legal principles applicable to this appeal are well settled. "[A] decision of a zoning board may be set aside only when it is `arbitrary, capricious or unreasonable.'" Cell S. of N.J., Inc. v. Zoning Bd. of Adjustment, 172 N.J. 75, 81 (2002). On an appeal from the trial court's decision, we employ the same standard of review as the trial court. N.Y. SMSA, Ltd. P'ship v. Bd. of Adjustment, 370 N.J.Super. 319, 331 (App. Div. 2004). Hence, like the trial court, we look to the municipal hearing record to determine whether the Board's decision was supported by sufficient credible evidence and was consistent with applicable law. See Rowatti v. Gonchar, 101 N.J. 46, 51-52 (1985). Like the trial court, we also owe deference to the Board's familiarity with local conditions in the community it serves. Kramer v. Bd. of Adjustment, 45 N.J. 268, 296 (1965).

We give greater deference to a Board's decision to deny a variance than to grant one, because "variances tend to impair sound zoning." Med. Ctr. at Princeton v. Twp. of Princeton Zoning Bd. of Adjustment, 343 N.J.Super. 177, 199 (App. Div. 2001); Omnipoint Commc'n, Inc. v. Bd. of Adjustment, 337 N.J.Super. 398, 416 (App. Div.), certif. denied, 169 N.J. 607 (2001). In reviewing the trial court's decision, we owe no deference to the trial court's interpretation of the law. Manalapan Realty, L.P. v. Twp. Comm., 140 N.J. 366, 378 (1995). Employing those legal standards, we find no basis to disturb the Board's determination or Judge Giles' well-reasoned decision.

On this appeal, plaintiffs contend that they were entitled to several variances under N.J.S.A. 40:55D-70(c)(1). The Municipal Land Use Law authorizes a board of adjustment to grant a variance if:

"Undue hardship" focuses "on whether the strict enforcement of the ordinance would cause undue hardship because of the unique or exceptional conditions of the specific property." Lang v. Zoning Bd. of Adjustment, 160 N.J. 41, 53 (1999). "[P]ersonal hardship is irrelevant to the statutory standard." Id. at 53. The conditions supporting the grant of a variance must be unique to the applicant's property and cannot exist on other properties in the zone. Beirn v. Morris, 14 N.J. 529, 535 (1954) ("A `variance' for undue hardship is grounded in conditions peculiar to the particular lot as distinguished from other property in the use district."); Terner v. Spyco, Inc., 226 N.J.Super. 532, 547-48 (App. Div. 1988) ("[A]n applicant for a hardship variance must show that his property is unique and different from other property in the zoning district.").

The applicant for a variance must also satisfy the statutory negative criteria:

The requirement that the variance not cause a "`substantial detriment to the public good' focuses on the impact the variance will have on the specific adjacent properties affected by the permitted deviations from the ordinance." Lang, supra, 160 N.J. at 57. "The requirement that the grant of the variance not `substantially impair the intent and the purpose of the zone plan and zoning ordinance' focuses on whether the grant of the variance can be reconciled with the zoning restriction from which the applicant intends to deviate." Ibid.

Applicants for a variance bear the burden of proving that they satisfy both the positive and negative criteria. See Cohen v. Bd. of Adjustment, 396 N.J.Super. 608, 615 (App. Div. 2007). We agree with Judge Giles that there was nothing arbitrary in the Board's decision that plaintiffs failed to satisfy the negative criteria. Based on the Board's factual findings, which find ample support in the record, granting the variances would have caused some of the very harms the zoning ordinance was designed to prevent, including diminishing the neighbors' light and open space, and invading their privacy. See N.J.S.A. 40:55D-2(c). Therefore, on this record, plaintiffs did not satisfy the negative criteria, and the Board properly denied their application on that basis.

On this appeal, plaintiffs contend that the Board gave inadequate weight to their expert's testimony and too much weight to the testimony of the objectors' expert. We find no merit in that argument. It was for the Board to decide which expert was more credible. See El Shaer v. Planning Bd., 249 N.J.Super. 323, 329 (App. Div.), certif. denied, 127 N.J. 546 (1991).

Plaintiffs also contend that the Township should be estopped from issuing a stop work notice. They argue that they applied for a zoning permit in good faith and reasonably relied on the issuance of the permit in spending $35,000 on the addition. They also argue that the setback violations are de minimis. We disagree.

The law is clear that to prove equitable estoppel in these circumstances, plaintiffs must establish that the zoning ordinance was ambiguous and the municipal official's interpretation of the ordinance was at least "debatable." See Hilton Acres v. Klein, 35 N.J. 570, 582-83 (1961); Irvin v. Twp. of Neptune, 305 N.J.Super. 652, 657 (App. Div. 1997); Jesse A. Howland & Sons Inc. v. Borough of Freehold, 143 N.J.Super. 484, 489 (App. Div.), certif. denied, 72 N.J. 466 (1976). See also Grasso v. Borough of Spring Lake Heights, 375 N.J.Super. 41, 47-48 (App. Div. 2004). "A less restrictive rule of law for invocation of estoppel against a municipality could invite intolerable vulnerability to mischief at the hands of unethical builders or construction officials." Irvin, supra, 305 N.J. Super. at 660. We do not imply here that plaintiffs acted unethically; we merely acknowledge that there are sound reasons to set a high standard for invoking estoppel based on the erroneous issuance of a land use permit.

Plaintiffs do not argue that the zoning ordinance at issue was unclear or that the municipal official's interpretation was debatable, as opposed to simply wrong. In fact, the record contains no explanation as to the responsible municipal official's interpretation of the zoning ordinance, and it is not even clear which person in the zoning office was responsible for erroneously issuing the permit. Because the zoning office acted contrary to an unambiguous ordinance in issuing a zoning permit, plaintiffs cannot invoke estoppel against the municipality.

Further, the equities do not favor plaintiffs, given the Board's finding that granting the variance would cause harm to their neighbors. As built, the second-story addition was 2.57 feet from the neighbors' property line on the westerly side, instead of the six feet required by the ordinance. As the Board reasonably concluded, in such a crowded neighborhood, that represented a significant incursion on the neighbors' privacy. Further, as previously noted, the Board credited the testimony of the objectors that the addition interfered with their available light and their views of the neighborhood.

Plaintiffs' reliance on Hill v. Board of Adjustment, 122 N.J.Super. 156 (App. Div. 1972), is misplaced. More recent cases such as Howland have clarified that the issuance of a permit, in clear contravention of a municipal ordinance, is insufficient to support an estoppel claim, even if plaintiffs relied on it. To form a basis for estoppel, there must have been at least some "good faith" arguable basis for the issuance of the permit. Irvin, supra, 305 N.J Super. at 657; Howland, supra, 143 N.J. Super. at 489. See Hilton, supra, 35 N.J. at 582-83.

Further, unlike the objector in Hill, plaintiffs' neighbors did not passively sit back and wait for plaintiffs to finish the addition before they objected to it. See Hill, supra, 122 N.J. Super. at 163. Many of the neighbors testified that as soon as they saw the size of the addition plaintiffs were building, they started making phone calls to the municipal offices inquiring about the legality of the addition. Because plaintiffs built the addition so quickly, they incurred substantial expense before the zoning official responded to the neighbors' protests. Under all the circumstances, plaintiffs were not entitled to the extraordinary equitable remedy of estoppel.

Affirmed.