2. As used in this act:
"Mortgage loan" means any indebtedness secured by a mortgage on a residential property, which mortgage shall constitute a first lien on the property;
"Residential property" means any real property including land or, in the case of condominiums, an interest in a lot of land, which real property shall consist of a single one or two family dwelling, including appropriate garages or other outbuildings, or unimproved real property if the proceeds of the mortgage loan shall be used exclusively for the purposes of erecting such a single one or two family dwelling thereon.