Rental housing shall mean a specific work or improvement within this state undertaken primarily to provide rental dwelling accommodations for low-income or moderate-income persons, which work or improvement shall include the acquisition, construction, reconstruction, or rehabilitation of land, buildings, and improvements thereto and such other nonhousing facilities, including commercial facilities, as may be appurtenant thereto so long as the cost of such nonhousing facilities does not exceed twenty percent of the total cost of the rental housing.