(3) That not only is it in the interest of the public health, safety, convenience and welfare to eliminate existing substandard areas of all types, but it is also in the public interest and less costly to the community to prevent the creation of new blighted areas or the expansion of existing blighted areas; that vigorous enforcement of municipal and State building standards, sound planning of new community facilities, public acquisition of dilapidated, obsolescent buildings, and other municipal action can aid in preventing the creation of new blighted areas or the expansion of existing blighted areas; and that rehabilitation, conservation, and reconditioning of areas in accordance with sound and approved plans, where, in the absence of such action, there is a clear and present danger that the area will become blighted, will protect and promote the public health, safety, convenience and welfare. Therefore it is hereby declared to be the policy of the State of North Carolina to protect and promote the health, safety, and welfare of the inhabitants of its urban areas by authorizing redevelopment commissions to undertake nonresidential redevelopment in accord with sound and approved plans and to undertake the rehabilitation, conservation, and reconditioning of areas where, in the absence of such action, there is a clear and present danger that the area will become blighted.