A city or town may assist in the development or preservation of publicly or privately owned housing for persons of low income by providing loans or grants of general municipal funds to the owners or developers of the housing. The loans or grants shall be authorized by the legislative authority of the city or town. They may be made to finance all or a portion of the cost of construction, reconstruction, acquisition, or rehabilitation of housing that will be occupied by a person or family of low income. As used in this section, "low income" means income that does not exceed eighty percent of the median income for the standard metropolitan statistical area in which the city or town is located. Housing constructed with loans or grants made under this section shall not be considered public works or improvements subject to competitive bidding or a purchase of services subject to the prohibition against advance payment for services: PROVIDED, That whenever feasible the borrower or grantee shall make every reasonable and practicable effort to utilize a competitive public bidding process.