A corner lot platted on the Borough's tax maps as the lot existed at the time of adoption of this Chapter, or any corner lot shown on any subdivision plat which received approval prior to the adoption of this Chapter, in which the application of paragraph c(1)(b) above would render said lot unbuildable, on approval of the Planning Board, may be permitted to encroach into one or both of the required side yard or front yard, as the case may be, in such a manner as the Planning Board may decide is consistent with the objectives of good planning and zoning, provided it can be done without any adverse effect on any adjacent lots.