The Residential Conservation (RC) zone is established to encourage conservation of existing housing by limiting the use of a given lot or parcel to the legal use existing on April 2, 2002. Legally existing uses may continue indefinitely and are intended to be treated as conforming uses. Such uses may be replaced as provided in this Chapter. However, if existing residential uses are replaced, new development is to be established at not more than the same density as legally existed on April 2, 2002.