This zone is established to recognize existing area of two family homes in certain sections of the Borough, and to allow a limited amount of new two family home construction and conversion of existing large homes under strict development standards; as well as to allow new office construction and conversion of existing residential buildings to office use, again, under strict development standards, recognizing that there is a need for such offices in the community and that the areas involved are less appropriate for exclusive, one family residential development than the R-I zone.