All moneys received from the sale of the revenue bonds herein authorized, together with all moneys received by donation, gift, bequest or otherwise, shall be placed by the city in a special fund which shall be known as the “home for the aged fund” the fund may be used for the purpose of establishing or acquiring a home for the aged or for the payment of existing debt on an acquired home as in this act provided. Whenever sufficient moneys are available in the fund, the governing body of the city may proceed to acquire the site by gift or purchase and let the contract for such building or buildings and the equipment therefor or to acquire by gift or purchase an existing adult care home to be used as a home for the aged. No building shall be erected or constructed until the plans and specifications have been made therefor and adopted by the governing body of the city and bids advertised for according to law as for other city buildings.