At any time after a county or counties is excluded from the area of operation of a regional housing authority as provided above, the board of supervisors of any such county may adopt a resolution declaring that there is a need for a housing authority in the county, if the board shall find such need according to the provisions of § 36-4. Thereupon a political subdivision of the Commonwealth to be known as the housing authority of the county shall exist for such county and may transact business and exercise its powers in the same manner as though created by § 36-4. Nothing contained herein shall be construed as preventing such county from thereafter being included within the area of operation of a regional housing authority as provided in § 36-40 or 36-41.