293 A.2d 622 Durkin Contracting Company v. Zoning Board of Adjustment. Commonwealth Court of Pennsylvania.Argued May 2, 1972 July 26, 1972. Zoning — Hearing de novo — Additional testimony — Scope of appellate review — Error of law — Abuse of discretion — Variance — Burden of proof — Unnecessary hardship — Public welfare. 1. […]