The defendant, Town of Enfield (town), appeals an order of the Superior Court {Smith, J.) vacating the decision of the zoning board of adjustment (ZBA) denying a variance to the plaintiffs, Russell and Lindsay Shopland. We reverse and remand.
The following facts were found by the trial court or are evident from the record. The Shoplands own á seasonal cottage along the shores of Crystal Lake in the town of Enfield. The cottage consists of one room and a bathroom for a total of approximately 378 square feet of living space. The Shoplands wished to expand the cottage by building a two-bedroom, one-bathroom addition, adding an additional 338 square feet of living space.
The Shoplands’ property is subject to article IV, section 401.2M of the Town of Enfield zoning ordinance (ordinance), which prohibits structures within fifty feet of the seasonal high water mark of Crystal Lake. Like most of the properties around the lake, almost all of the Shoplands’ home is .within the fifty-foot setback as a pre-existing, nonconforming use. Under article IV, section 413.3 of the ordinance, any expansion of the footprint of a nonconforming use requires a variance.
The Shoplands’ proposed addition would be located to the north of the cottage running along the existing wall, which is approximately twenty-five feet from the lake, thus imposing no further encroachment on the lake. Because the addition was an expansion of a nonconforming use within the fifty-foot setback, the Shoplands sought a variance.
At the ZBA hearing, the town’s Conservation Commission recommended, after reviewing the application and visiting the site, that the ZBA deny the variance because there was no hardship. The ZBA reviewed the criteria for granting a variance and expressed concerns about the potential damage to the lake by building within the setback. When asked about the alternative of adding another story, Mr. Shopland stated that the home was on pylons without a sturdy foundation. The hearing was continued so that the ZBA members could visit the site.
*221At the reconvened hearing, the ZBA again expressed concerns with the potential impact of additional development on the lake and the overcrowding of the lake. In a letter to the ZBA, Mr. Shopland stated that if another story was added, the cottage would be more visible from the water.
The ZBA denied the variance because: (1) it was “contrary to the public interest in that further violating the setback might endanger the health of the lake and establish a bad precedent”; (2) denying the variance did not result in unnecessary hardship; and (3) the substantial justice provided to the Shoplands was “outweighed by the potential loss suffered by the general public if harm is done to the lake.” In finding that the Shoplands did not establish unnecessary hardship, the ZBA noted that “many of the other lots in the area suffer the same topographical problems.”
In a motion for rehearing, Mr. Shopland stated that he had established unnecessary hardship because, given the topography of his property, the proposed location was the only feasible place for the addition. He pointed out that a brook to the south and a steep slope to the west prevented expanding in those directions. Mr. Shopland also stated that “[b]uilding a second story would require a foundation, require the removal of trees and further impact the view from the lake.” The ZBA denied the motion for rehearing.
The Shoplands appealed the ZBA’s decision to the superior court. Following a hearing, the court granted the Shoplands’ appeal, vacating the ZBA’s decision.
In applying the first prong of the standard for unnecessary hardship set forth in Simplex Technologies v. Town of Newington, 145 N.H. 727 (2001), the court found that the addition did not change the use of the property and that it was “not inherently unreasonable to wish to construct two small bedrooms and a bathroom for a seasonal retirement residence.” The court further found that the property was unique so as to make the zoning restriction unreasonable because there were only two directions the Shoplands could build in conformance with the zoning ordinance, neither of which, the court determined, was reasonable. The court determined that building to the west (the rear of the cottage) was not reasonable because the land sloped steeply upwards and that building on the lower slope would interfere with access to the property while building on the upper slope would interfere with the septic system. In addition, the court determined that constructing a second story was not reasonable because “the necessary excavation for a foundation would constitute a far greater disturbance both of the surface drainage to the lake and the habitat around it.” After considering the other Simplex factors, the court found that the Shoplands had proved the existence of unnecessary hardship in *222accordance with the Simplex standard and, therefore, the ZBA erred in denying their request for a variance.
On appeal, the town argues that the trial court erred in finding that the Shoplands satisfied their burden of proving unnecessary hardship. Our review of zoning cases is limited. Hill v. Town of Chester, 146 N.H. 291, 292 (2001). The factual findings of the ZBA are deemed prima facie lawful and reasonable, and will not be set aside by the superior court absent errors of law, unless the court is persuaded, based upon a balance of the probabilities, on the evidence before it, that the ZBA’s decision is unreasonable. Duffy v. City of Dover, 149 N.H. 178, 180 (2003). The party seeking to set aside the ZBA’s decision bears the burden of proof on appeal to the superior court. Id. We will uphold the superior court’s decision on appeal unless it is not supported by the evidence or is legally erroneous. Id. Our inquiry is not whether we would find as the trial court found, but rather whether the evidence before the court reasonably supports its findings. Id.
We have established a five-part test for the granting of variances. To obtain a variance, a landowner has the burden of showing that: (1) the variance will not be contrary to the public interest; (2) special conditions exist such that literal enforcement of the ordinance results in unnecessary hardship; (3) the variance is consistent with the spirit of the ordinance; (4) substantial justice is done; and (5) granting the variance will not diminish the value of surrounding properties. Robinson v. Town of Hudson, 149 N.H. 255, 256-57 (2003); see RSA 674:33, I(b) (1996).
In order to establish the unnecessary hardship factor where the landowner is seeking an area variance, we recently set forth two factors that a landowner is required to prove:
(1) whether an area variance is needed to enable the applicant’s proposed use of the property given the special conditions of the property; and (2) whether the benefit sought by the applicant can be achieved by some other method reasonably feasible for the applicant to pursue, other than an area variance.
Boccia v. City of Portsmouth, 151 N.H. 85, 92 (2004) (citations omitted).
The superior court, applying the Simplex standard, found that the Shoplands had established unnecessary hardship. In light of our decision in Boccia, the Shoplands’ variance application must be reviewed under the two factors for establishing unnecessary hardship in an area variance application. See Estate of Ireland v. Worcester Ins. Co., 149 N.H. 656, 659-60 (2003) (giving new rules full retroactive effect in civil cases).
*223Whether the Boccia standard is met in this case will depend upon the application of these factors to the Shoplands’ variance request. See Britton v. Town of Chester, 134 N.H. 434, 441 (1991) (“It is not... within the power of this court to act as a super zoning board.”) Accordingly, we reverse and remand for proceedings consistent with this opinion. On remand, the superior court should consider whether the case needs to be remanded to the ZBA to allow further evidence and proceedings before it at which the parties can address the Boccia standard.
Reversed and remanded.
Broderick, C.J., and Dalianis, J., concurred; Nadeau, J., with whom BROCK, C.J., retired, specially assigned under RSA 490:3, joined, dissented.