Cal. Health & Safety Code § 51177

The agency may make and undertake commitments to make construction loans and mortgage loans to finance residential structures without the participation of a qualified mortgage lender where the income of the owner-occupant is no greater than 65 percent of the median income for the area in which the residential structure is located as determined by the United States Department of Housing and Urban Development or by the agency’s reference to current data of the U.S. Census Bureau. The income at 65 percent of median shall be based on a family of four with adjustments above and below such maximum to compensate for family size.