This district is composed of residential uses plus certain open areas where similar residential development appears likely to occur. The regulations for this district are designed to stabilize and protect the essential characteristics of the district, to promote and encourage a suitable environment for family life and to prohibit activities of a low concentration, and permitted uses are limited basically to single-unit dwellings providing homes for the residents plus certain additional uses, such as schools, parks, churches and certain public facilities that serve the residents of the district.