Opinion by

Robert C. and Marcella M. Boss (owners) appeal from an Allegheny County Common Pleas Court order dismissing their appeal from a Zoning Hearing Board (Board) decision which upheld the Borough of Bethel Park’s1 zoning ordinance. We reverse and remand.2

*91The Borough Council denied the owners’ request to have their property rezoned from single-family residential use to townhouse development. The owners then applied to the Board, challenging the Borough zoning ordinance’s validity. After the Board denied their challenge, owners appealed to the common pleas eourt,3 but the appeal was denied.

Owners’ claim is two-fold: first, that the lower court erred proeedurally by failing to decide the case on its merits although basing its opinion on facts developed through discovery after appeal was taken from the Board’s decision; and, second, that the court committed substantive error by failing to sustain the challenge to the local zoning ordinance. Since we must remand because of procedural error, analysis of the substantive claim will not be undertaken.

When the court below considers additional evidence in a zoning appeal, we must determine on review whether that court committed legal error or abused its discretion. Appeal of Nardozza, 45 Pa. Commonwealth Ct. 482, 483, 405 A.2d 1020, 1021 (1979). We conclude that legal error was made.

Although it is obvious that the lower court’s decision rested, at least in part, on the Borough’s answers to the owners’ interrogatories, the judge limited his review to a determination of whether the Board had ooramitted legal error or abused its discretion. Where the court below takes additional evidence in a zoning *92appeal, it must decide the case on the merits. Lutz v. East Hanover Township Zoning Hearing Board, 17 Pa. Commonwealth Ct. 501, 504, 333 A.2d 229, 230 (1975). Having taken additional evidence, it was the lower court’s duty to determine the case de novo rather than to review only for the Board’s possible commission of legal error or abuse of discretion. Pantry-Quik, Inc. v. Zoning Board of Adjustment, 1 Pa. Commonwealth Ct. 326, 329, 274 A.2d 571, 572 (1971). As Judge Wilkinson so aptly noted in Boron Oil Co. v. Baden Borough, 6 Pa. Commonwealth Ct. 583, 584-85, 297 A.2d 833, 834 (1972):

Very few principles of zoning law are as well established as the principle that if the lower court considers any testimony that was not before the Board, the lower court must decide the ease on the merits, normally making findings of fact and conclusions of law, so that this or any other appellate court can determine the basis for the lower court’s decision and whether there is testimony to support it.

Additional evidence, even if characterized as inconsequential or as adding nothing new to the case, requires the lower court to decide the case on the merits since the posture of the case with the new evidence is not the same as without it. Lutz, 17 Pa. Commonwealth Ct. at 504, 333 A.2d at 230. Where, as here, the common pleas court took additional evidence but failed to make specific legal and factual findings, we must remand reluctantly so that the lower court may decide the case de novo on the merits, making appropriate fact findings and legal conclusions.

Reversed and remanded.4

*93Order

The Allegheny County Common Pleas Court order, Case No. SA 136 of 1977, dated December 15, 1980, is reversed and remanded for proceedings not inconsistent with this opinion.