If, for a continuous period of two years, either the non-conforming use of land with minor improvements is discontinued, or the active operation of substantially all the non-conforming uses in any building or other structure is discontinued, such land or building or other structure shall thereafter be used only for a conforming use. Intent to resume active operations shall not affect the foregoing.

The provisions of this Section shall not apply where such discontinuance of active operations is directly caused by war, strikes or other labor difficulties, a governmental program of materials rationing, or the construction of a duly authorized improvement project by a governmental body or a public utility company.

However, the provisions of this Section shall also not apply to vacant ground floor or basement stores in buildings designed for residential use located in R1 through R10 Districts, where the changed or reactivated use is a use listed in Use Group VI that would be permitted in a C1 District that is a select commercial overlay, or an office, as listed in Use Group VII. 

In addition, the changed or reactivated use shall be subject to the provisions of Section 52-34 (Commercial Uses in Residence Districts).