That the board of county commissioners of any county which has, prior to the effective date of this act, been authorized to sell real property, the same being part of a county farm, by a majority vote of the legal electors of such county voting at an election held for such purpose, may sell such real property, and place the moneys derived from the sale in a special building fund. Such special building fund may be expended by said board of county commissioners to repair or construct and equip a building for the housing, maintenance and care of social welfare clients. Such expenditures may be made during the remainder of the calendar year 1951 even though such expenditures were not included in the budget for such period.