¶ 71. (concurring). I concur with the lead opinion and mandate, but reach the conclusion to reverse the court of appeals and affirm the issuance of a variance by a different route. I write separately because I see no reason to overrule State v. Kenosha County Bd. of Adjustment, 218 Wis. 2d 396, 577 N.W.2d 813 (1998). Stare decisis is a cornerstone of the judicial process, and, absent a compelling reason to overrule precedent, this court should abide by that precedent. CBS, Inc. v. LIRC, 219 Wis. 2d 564, 586-87, 579 N.W.2d 668 (1998) (Crooks, J., concurring).
¶ 72. I agree with the lead opinion's analysis of Wis. Admin. Code § NR 116.13(2) and Outagamie County Shoreland-Floodplain-Wetland Zoning Ordinances §§ 16.32, 16.35, and 16.40. It is with the lead opinion's interpretation of the "unnecessary hardship" standard that I part company, however. The "unnecessary hardship" standard was addressed in Snyder v. *656Waukesha County Zoning Bd. of Adjustment, 74 Wis. 2d 468, 247 N.W.2d 98 (1976). Prior to the time Snyder was decided, area variances apparently were granted based upon a showing of "practical difficulties" which was "something much less severe than unnecessary hardship." Id. at 473. Use variances, in contrast, were granted upon a showing of "unnecessary hardship." Id. Snyder eliminated that distinction.
[W]e think that there should be no significant practical distinction drawn between the terms unnecessary hardship and practical difficulties, and where it appears, the phrase "practical difficulty or unnecessary hardship" should be construed as a whole, for where peculiar and exceptional practical difficulties, which justify a variance, exist, unnecessary hardship will also exist.
Id. at 474 (citation omitted). Whether an area or use variance should be granted depends upon the purpose underlying the specific provision of the zoning code to which a variance is being sought. Id. at 473. This is evident from what the lead opinion has already quoted from Snyder, and it is worth repeating:
[A]rea variances are not more easily obtained because practical difficulties are something much less severe than unnecessary hardship, but because area variances do not involve great changes in the character of neighborhoods as do use variances. This relates to what hardships or practical difficulties may be considered unnecessary or unreasonable in light of the purpose of the zoning law.
Id. (emphasis added).
¶ 73. Kenosha County did not explain the differences, if any real differences existed after Snyder, between area and use variances and the applicable *657tests for granting such variances. Instead, this court specifically refused to reach that issue.
Both parties, and the court of appeals, have spent some time trying to differentiate, either in words or in application, the tests for granting a use variance and an area variance. [However, n]either party disputes that Huntoon has requested an area variance. Thus, for purposes of this case, we need not decide whether there is a difference between the two types of variances, and what that difference may be.
Kenosha County, 218 Wis. 2d at 412 n.10. Kenosha County did consider the parties' definitions of the unnecessary hardship standard in light of the purpose of the shoreland zoning regulations at issue. The State proffered a "no reasonable use in the absence of a variance" standard; the Board proffered an "unnecessarily burdensome" standard.1 Id. at 411-12. This court concluded that the State's test better incorporated the purpose underlying the regulations, "to enforce a uniform setback that preserves the public's interest in *658shoreland and the navigable waters of the state." Id. at 413.
¶ 74. Kenosha County, like Snyder, reiterated that "whether a particular hardship is unnecessary or unreasonable is judged against the purpose of the zoning law." Kenosha County, 218 Wis. 2d at 412-13. Within this general parameter, county boards of adjustment have some very real flexibility in granting variances. The boards can determine, by looking to the purpose underlying the ordinance at issue, what reasonably constitutes an unnecessary hardship. Implicit in considering the variance request in relation to the ordinance's purpose is consideration of the nature of the restriction in the ordinance. That is, boards of adjustment should also consider whether the restriction involves, for example, "set backs, frontage, height, bulk or density" (Snyder, 74 Wis. 2d at 475), or whatever restriction is at issue. Consideration of a variance request as it relates to the purpose of the zoning ordinance, along with review of the specific restriction at issue, must necessarily take into account the differences resulting from the granting of an area or use variance. Indeed, "because area variances do not involve great changes in the character of neighborhoods as do use variances," the purpose of the zoning ordinance may not be so likely undermined by an area variance as it might be by a use variance.
¶ 75. That the county boards of adjustment have flexibility in granting and denying variances is reflected in the standard by which courts review decisions of the boards. This, too, was reiterated in Kenosha County.
Reviewing courts accord a decision of a board of adjustment a presumption of correctness and valid*659ity. A reviewing court may not substitute its discretion for that committed to the Board by the legislature. However, when a Board of Adjustment acts on application for a variance, it acts in a quasi-judicial capacity. The Board's action must be based upon evidence. On certiorari review, a reviewing court applies the substantial evidence test to ascertain whether the evidence before the Board was sufficient. If any reasonable view of the evidence would sustain the findings of the Board, the findings are conclusive.
218 Wis. 2d at 415-16 (internal citations omitted).
¶ 76. Accordingly, this court presumes that the Outagamie Board of Adjustment's decision is correct and valid. At issue here are shore-land/floodplain/wetland ordinances which may have some overlapping purposes with the shoreland ordinances at issue in Kenosha County. According to the Board's findings here, however, it did not consider the purpose underlying that ordinance. The Board did not contemplate whether the Warnings' hardship — that they would have to fill in the basement, or be forced to sell the house with a non-conforming basement, or move the house onto a conforming basement — was unnecessary or unreasonable in order to protect the public health and welfare in the flood fringe district where the Warnings resided.2 Nor did the Board consider whether, per Kenosha County, there was "no reasonable use in the absence of a variance." The Board may have concluded that the Warnings would have had some reasonable use of their property without a vari-*660anee — that is, they need only fill their basement or move their house. However, the "no reasonable use" language of Kenosha County should have been applied by the Board only after considering the purpose of the zoning ordinance, and the nature of the specific restriction at issue. A reviewing court should then look at whether the Board considered such matters when applying the presumption of correctness and validity and the substantial evidence test.
¶ 77. Because the Outagamie County Board of Adjustment did not consider the purpose of the underlying ordinance or Kenosha County's "no reasonable use" test, this case might be remanded to the Board to determine whether the Warnings are entitled to a variance in consideration of the purpose of the ordinances at issue and the nature of the restriction involved. However, remand is not necessary because the Board properly considered that a variance was in order, due to the fact that the Warning's hardship had been caused "by the Town of Bovina and the building inspector."3 (See Outagamie County Board of Adjustment's findings at ¶ 17 of the lead opinion.)
*661¶ 78. The Outagamie County Board of Adjustment apparently realized that the circumstances here effectively estopped the Board from denying the Warning's variance request. Apparently, the Warnings needed, in addition to the building permit from the Town of Bovina, a zoning permit from the County. Although the Warnings needed the additional zoning permit, there is no contention that the building permit issued was invalid. The Town had issued a building permit, upon which the Warnings depended in building their house. Consequently, we do not have before us the situation that existed in Snyder, where the variance applicant had proceeded with construction before he obtained a permit — which would have been an "unauthorized act[]" of a municipal officer and "void as issued for a structure which is forbidden by the ordinance." 74 Wis. 2d at 477. Nor do we have before us the situation where a subordinate municipal officer acted erroneously, and the municipality later sought to enforce a zoning ordinance.4 See Willow Creek Ranch v. *662Town of Shelby, 2000 WI 56, ¶ 56, 235 Wis. 2d 409, 611 N.W.2d 693; Milwaukee v. Leavitt, 31 Wis. 2d 72, 78, 142 N.W.2d 169 (1966); see also Jelinski v. Eggers, 34 Wis. 2d 85, 94, 148 N.W.2d 750 (1967) ("[E]stoppel should not apply to an adjacent property owner seeking enforcement of the ordinance who was in no way responsible for the issuance of the building permit."). Rather, this case is closer to Russell Dairy Stores v. Chippewa Falls, 272 Wis. 138, 74 N.W. 759 (1956), wherein the city had issued a permit to cut a curb and construct a driveway, and then subsequently rescinded the permit. Id. at 141-42. Here, the Town of Bovina issued a building permit without also, at the very least, notifying the Warnings that they also needed a zoning permit to proceed. For the County not to grant an after-the-fact variance — 11 years after the fact — would be akin to rescinding a permit after the Warnings had long relied upon it.
¶ 79. Typically, equitable concerns, such as estoppel, would be considered during an enforcement action. See, e.g., Forest County v. Goode, 219 Wis. 2d 654, 681-82, 579 N.W.2d 715 (1998). However, we are faced with unique circumstances here that required *663the Outagamie Board of Adjustment to consider estop-pel in concluding that the Warnings faced an unnecessary hardship. In applying the substantial evidence test, I am satisfied that a reasonable view of the evidence supports the Board's findings that the Town of Bovina and the building inspector caused the Warnings' predicament, and those findings are conclusive. Kenosha County, 218 Wis. 2d at 416. Similarly, as noted previously, the Board's decision is entitled to a presumption of correctness and validity. Id. at 415.
¶ 80. In sum, I agree with the lead opinion that the Outagamie County Board of Adjustment correctly issued a variance to the Warnings. However, I find no compelling reason to overrule Kenosha County. Instead, I read Kenosha County as applying the rule from Snyder, that the purpose of the ordinance guides the determination of whether there is an unnecessary hardship that would warrant a variance. I recognize that the Board did not consider the purpose of the ordinances at issue in granting the Warnings a variance for their non-conforming basement, in order to obtain a permit to build a sun porch. However, the Board "proceeded on a correct theory of law" in concluding, in effect, that it was estopped from doing otherwise. Kenosha County, 218 Wis. 2d at 410. For these reasons, I respectfully concur with the lead opinion and the mandate.
¶ 81. I am authorized to state that Justice JON P. WILCOX joins this opinion.
Even though the court declined to comment on the difference between an area and use variance, the two tests proffered followed the two alternatives of Snyder's area variance unnecessary hardship standard.
When considering an area variance, the question of whether unnecessary hardship or practical difficulty exists is best explained as "[w]hether compliance with the strict letter of the restrictions governing area, set backs, frontage, height, bulk or density would unreasonably prevent the owner from using the property for a permitted purpose or would render conformity with such restrictions unnecessarily burdensome." 2 Rathkopf, The Law of Zoning and Planning 45-28 (3d ed. 1972).
Snyder v. Waukesha county Zoning Bd. of Adjustment, 74 Wis. 2d 468, 474-75, 247 N.W.2d 98 (1976) (emphasis added).
The unnecessary hardship here is not that the Warnings are not allowed to build a sun porch. The hardship is that they have a non-conforming basement, resulting in the problems noted herein.
The building permit was granted by the "Town Building Inspector," however, the heading on the document indicates that it was from the Office of the Building Inspector, Outagamie County, and was directed to the Outagamie County Building Inspector.
The Outagamie County Board of Adjustment did not find that the County Planning and Zoning Administration may have added to the Warnings' hardship, but it appears that the Board could have. The Board found that the Outagamie County Zoning Department was not contacted, at the time that the Town had issued the Warnings a building permit, regarding issuance of a shoreland zoning permit. (There is no indication that the Department is different than the Planning and Zoning Administration.) According to 1995 correspondence from the Planning *661and Zoning Administration to the Warnings, however, the Administration had a "record of.. .the building permit issued by the Town.” It seems apparent that the County was on notice, at some point, that the Warnings had a building permit, but not the necessary shoreland zoning permit. Yet, the County did nothing until 1995. Consequently, it appears that the County was as much a part of causing the Warning's hardship as the Town.
The dissent has ignored the important distinction between this case and Snyder, 74 Wis. 2d 468, and Willow Creek Ranch v. Town of Shelby, 2000 WI 56, ¶ 56, 235 Wis. 2d 409, 611 N.W.2d 693. In Snyder and Willow Creek, the applicant attempted to assert estoppel to prevent the municipality from enforcing its zoning ordinance. Snyder, 74 Wis. 2d at 476; Willow Creek, 2000 WI 56 at ¶ 49. "Although municipalities are not wholly immune from the doctrine of equitable estoppel, it is well *662established that erroneous acts or representations of municipal officers do not afford a basis to estop a municipality from enforcing zoning ordinances enacted pursuant to the police power." Willow Creek, 2000 WI 56 at ¶ 49 (citing, among others, Snyder, 74 Wis. 2d at 476-77) (footnote and other citations omitted). However, here, in contrast, it is the Outagamie Board of Adjustment which has apparently considered that it was estopped from enforcing its zoning ordinances. There is nothing in Snyder, Willow Creek, or any of our other cases that suggests that a County Board of Adjustment cannot consider estoppel, when determining whether or not to grant a variance from the County's ordinance.