For the purposes of this division:
(a) “Owner” shall mean any person, partnership, association, company, corporation or fiduciary in whom or which is vested legal title to residential property as defined herein, or who or which possesses the power to convey legal title to such residential property.
(b) “Residential property” shall mean:
(1) Any real property improved with one or more buildings or structures which in whole or in part are used for or are legally permitted to be used for dwelling units or guest room purposes.
(2) Any vacant real property located in a zone wherein dwelling or guest room uses are legally permitted.
(c) “Agreement of sale” shall mean any agreement, reduced to writing, which provides that legal title of any real property shall thereafter be conveyed from one owner to another.
(d) “Brush abatement” shall mean those proceedings initiated by the City under the authority of Title 4, Division 3, Part 2, Chapter 13, of the Government Code of the State of California, where the Fire Department has determined that a fire hazard exists by reason of the presence upon real property of brush which the City Council may order removed under the authority of the above-mentioned chapter of the Government Code.