California Code, Civil Code - CIV § 911

(a) For purposes of this title, except as provided in subdivision (b), “builder” means any entity or individual, including, but not limited to a builder, developer, general contractor, contractor, or original seller, who, at the time of sale, was also in the business of selling residential units to the public for the property that is the subject of the homeowner's claim or was in the business of building, developing, or constructing residential units for public purchase for the property that is the subject of the homeowner's claim.

(b) For the purposes of this title, “builder” does not include any entity or individual whose involvement with a residential unit that is the subject of the homeowner's claim is limited to his or her capacity as general contractor or contractor and who is not a partner, member of, subsidiary of, or otherwise similarly affiliated with the builder.  For purposes of this title, these nonaffiliated general contractors and nonaffiliated contractors shall be treated the same as subcontractors, material suppliers, individual product manufacturers, and design professionals.