(h) The term “residential mortgage” means a mortgage which (1) is a mortgage on real estate, in fee simple or under a leasehold having such term as may be prescribed by the Corporation, upon which there is located a structure or structures designed in whole or in part for residential use, or which comprises or includes one or more condominium units or dwelling units (as defined by the Corporation) and (2) has such characteristics and meets such requirements as to amount, term, repayment provisions, number of families, status as a lien on such real estate, and otherwise, as may be prescribed by the Corporation. The term “residential mortgage” also includes a loan or advance of credit insured under title I of the National Housing Act [ 12 U.S.C. 1702 et seq.] whose original proceeds are applied for in order to finance energy conserving improvements, or the addition of a solar energy system, to residential real estate. The term “residential mortgage” also includes a loan or advance of credit for such purposes, or purchased from any public utility carrying out activities in accordance with the requirements of title II of the National Energy Conservation Policy Act [ 42 U.S.C. 8211 et seq.] if the residential mortgage to be purchased is a loan or advance of credit the original proceeds of which are applied for in order to finance the purchase and installation of residential energy conservation measures (as defined in section 210(11) of the National Energy Conservation Policy Act) in residential real estate, not having the benefit of such insurance and includes loans made where the lender relies for purposes of repayment primarily on the borrower’s general credit standing and forecast of income, with or without other security. The term “residential mortgage” is also deemed to include a secured loan or advance of credit the proceeds of which are intended to finance the rehabilitation, renovation, modernization, refurbishment, or improvement of properties as to which the Corporation may purchase a “residential mortgage” as defined under the first sentence of this subsection. Such term shall also include other secured loans that are secured by a subordinate lien against a property as to which the Corporation may purchase a residential mortgage as defined under the first sentence of this subsection. A “secured loan or advance of credit” is one in which a security interest is taken in the rehabilitated, renovated, modernized, refurbished, or improved property. Such term shall also include a mortgage, lien, or other security interest on the stock or membership certificate issued to a tenant-stockholder or resident-member by a cooperative housing corporation, as defined in section 216 of title 26 , and on the proprietary lease, occupancy agreement, or right of tenancy in the dwelling unit of the tenant-stockholder or resident-member in such cooperative housing corporation. The term “residential mortgage” also includes a loan or advance of credit secured by a mortgage or other lien on a manufactured home that is the principal residence of the borrower, without regard to whether the security property is real, personal, or mixed.