(a) "Owner" means any person, copartnership, association, corporation or fiduciary having legal or equitable title or any interest in any real property.

(b) "Residential building" means any improved real property designed or permitted to be used for dwelling purposes, situated in the city, and includes the building or structures located on said improved real property.

(c) "Agreement of sale" means any agreement or written instrument which provides that title to any property shall thereafter be transferred from one owner to another owner. (Ord. No. 2219 (NCS), § 1.)