The authority is hereby authorized from time to time to sell and issue its bonds, not exceeding $29,500,000.00, exclusive of refunding bonds, in aggregate principal amount, and in such additional aggregate principal amounts as shall be authorized by act of the Legislature, for the purpose of providing funds for the construction, renovation, reconstruction, improvement, addition to, demolition, and alteration of public office building facilities including the State Capitol, for the procurement of equipment therefor, and for payment of obligations incurred for any of said purposes.