Rights of housing authority after taking.

In any action in which any housing authority created under the laws of Florida has taken or may take possession of any real property in advance of final judgment therein, and the said petitioner has become irrevocably committed to pay the amount ultimately to be awarded as compensation, then it is lawful to expend moneys duly appropriated for that purpose in demolishing existing structures on said land, and in erecting buildings or public works thereon, or in improving said land or erecting and constructing buildings or works thereon, authorized by law to be constructed by any petitioner.