The Secretary shall set upper limits on the income that a family or individual may have to qualify as a family of limited income. In setting the limits, the Secretary shall consider factors that include: the portion of the total family income available for housing; the size of the family; the cost and condition of available housing; the ability of the family to compete successfully in the private housing market; and relevant standards and definitions established for federal and State housing programs. The Secretary may waive income limits for a borrower or occupant seeking a Program loan to rehabilitate a building that the State historical preservation officer finds historically or architecturally significant.