Conversion or use of building. The conversion of any use or building either to another use or to increase the size or area of the existing use, including the conversion of any building into a dwelling or the conversion of any dwellings to accommodate an increased number of dwelling units, families or residents, shall be permitted only within a zoning district in which a new building for similar occupancy would be permitted under this chapter, and only when the resulting occupancy will comply with the requirements governing new construction in such district, with respect to minimum lot size, lot area per dwelling unit, dimension of yards and other open spaces, height, off-street parking and other applicable requirements.