The agency may insure or guarantee any obligation held by the agency and secured by a mortage on a housing development or residential structure for the purpose of increasing its acceptability or value for sale or as security for other obligations. The agency may also insure or guarantee any loan, or participation in a loan, for rehabilitation or home improvement which is insured by an agency or instrumentality of the United States and which is held by the agency. Nothing in this section shall, however, be construed as authorizing the creation of a debt or liability of the state within the meaning of Section 1 of Article XVI of the State
Constitution.