have been made to, and be held by, a mortgagee approved by the Secretary as responsible and able to service the mortgage properly;

involve a principal obligation (including such initial service charges, appraisal, inspection, and other fees as the Secretary shall approve) in an amount not to exceed $5,700, and not to exceed 95 per centum of the appraised value, as of the date the mortgage is accepted for insurance, of a property upon which there is located a dwelling designed principally for a single-family residence, and which is approved for mortgage insurance prior to the beginning of construction: Provided, That the mortgagor shall be the owner and occupant of the property at the time of insurance and shall have paid on account of the property at least 5 per centum of the Secretary’s estimate of the cost of acquisition in cash or its equivalent, or shall be the builder constructing the dwelling, in which case the principal obligation shall not exceed 85 per centum of the appraised value of the property or $5,100: Provided further, That the Secretary finds that the project with respect to which the mortgage is executed is an acceptable risk, giving consideration to the need for providing adequate housing for families of low and moderate income particularly in suburban and outlying areas: And provided further, That, where the mortgagor is the owner and occupant of the property and establishes (to the satisfaction of the Secretary) that his home, which he occupied as an owner or as a tenant, was destroyed or damaged to such an extent that reconstruction is required as a result of a flood, fire, hurricane, earthquake, storm or other catastrophe, which the President, pursuant to sections 5122(2) and 5170 of title 42, has determined to be a major disaster, such maximum dollar limitation may be increased by the Secretary from $5,700 to $7,000, and the percentage limitation may be increased by the Secretary from 95 per centum to 100 per centum of the appraised value;

have a maturity satisfactory to the Secretary but not to exceed thirty years from the date of insurance of the mortgage;

contain complete amortization provisions satisfactory to the Secretary requiring periodic payments by the mortgagor not in excess of his reasonable ability to pay as determined by the Secretary;

bear interest (exclusive of premium charges for insurance and service charges, if any) at not to exceed 5 per centum per annum on the amount of the principal obligation outstanding at any time;

provide, in a manner satisfactory to the Secretary, for the application of the mortgagor’s periodic payments (exclusive of the amount allocated to interest and to the premium charge which is required for mortgage insurance as hereinafter provided and to the service charge, if any) to amortization of the principal of the mortgage; and

contain such terms and provisions with respect to insurance, repairs, alterations, payment of taxes, service charges, default reserves, delinquency charges, foreclosure proceedings, anticipation of maturity, and other matters as the Secretary may in his discretion prescribe.