The area of operation of a regional housing authority shall be increased from time to time to include one or more additional contiguous counties not already within a regional housing authority if the board of supervisors of each of the counties then included in the area of operation of such regional housing authority, the commissioners of the regional housing authority and the board of supervisors of each such additional county or counties each adopt a resolution declaring that there is a need for the inclusion of such additional county or counties in the area of operation of such regional housing authority. Upon the adoption of such resolutions, the county housing authority created for each such additional county shall cease to exist except for the purpose of winding up its affairs and executing a deed to the regional housing authority as hereinafter provided; provided, however, that such resolutions shall not be adopted if there is a county housing authority created for any such additional county which has any obligations outstanding unless first, all obligees of any such county housing authority and parties to the contracts, bonds, notes, and other obligations of any such county housing authority consent in writing to the substitution of such regional housing authority in lieu of such county housing authority on all such contracts, bonds, notes, or other obligations; and second, the commissioners of such county housing authority adopt a resolution consenting to the transfer of all the rights, contracts, obligations, and property, real and personal, of such county housing authority to such regional housing authority as hereinafter provided; and provided further that when the above two conditions are complied with and the area of operation of such regional housing authority is increased to include such additional county, as hereinabove provided, all rights, contracts, agreements, obligations, and property of such county housing authority shall be in the name of and vest in such regional housing authority, all obligations of such county housing authority shall be the obligations of such regional housing authority and all rights and remedies of any person against such county housing authority may be asserted, enforced, and prosecuted against such regional housing authority to the same extent as they might have been asserted, enforced, and prosecuted against such county housing authority. When any real property of a county housing authority vests in a regional housing authority as provided above, the county housing authority shall execute a deed of such property to the regional housing authority which thereupon shall file such deed in the office provided for the filing of deeds, provided that nothing contained in this sentence shall affect the vesting of property in the regional housing authority as provided above. The board of supervisors of each of the counties in the regional housing authority, the commissioners of the regional housing authority and the board of supervisors of each such additional county or counties shall by resolution declare that there is need for the inclusion of such county or counties in the area of operation of the regional housing authority, if (a) the board of supervisors of each such additional county or counties finds that insanitary or unsafe inhabited dwelling accommodations exist in such county or there is a shortage of safe or sanitary dwelling accommodations in such county available to persons of low income at rentals they can afford and (b) the board of supervisors of each of the counties then included in the area of operation of the regional housing authority, the commissioners of the regional housing authority and the board of supervisors of each such additional county or counties find that the regional housing authority would be a more efficient or economical administrative unit to carry out the purposes of this Housing Authorities Law if the area of operation of the regional housing authority is increased to include such additional county or counties.