Cal. Business and Professions Code § 7151

(a) “Home improvement” means the repairing, remodeling, altering, converting, or modernizing of, or adding to, residential property, as well as the reconstruction, restoration, or rebuilding of a residential property that is damaged or destroyed by a natural disaster for which a state of emergency is proclaimed by the Governor pursuant to Section 8625 of the Government Code, or for which an emergency or major disaster is declared by the President of the United States, and shall include, but not be limited to, the construction, erection, installation, replacement, or improvement of driveways, swimming pools, including spas and hot tubs, terraces, patios, awnings, storm windows, solar energy systems, landscaping, fences, porches, garages, fallout shelters, basements, and other improvements of the structures or land which is adjacent to a dwelling house. “Home improvement” shall also mean the installation of home improvement goods or the furnishing of home improvement services. (b) For purposes of this chapter, “home improvement goods or services” means goods and services, as defined in Section 1689.5 of the Civil Code, which are bought in connection with the improvement of real property. Such home improvement goods and services include, but are not limited to, carpeting, texture coating, fencing, air conditioning or heating equipment, and termite extermination. Home improvement goods include goods which are to be so affixed to real property as to become a part of real property whether or not severable therefrom. (c) For purposes of this article, “solar energy system” means a solar energy device to be installed on a residential building or residential property that has the primary purpose of providing for the collection and distribution of solar energy for the generation of electricity, that produces at least one kilowatt, and not more than five megawatts, alternating current rated peak electricity, and that meets or exceeds the eligibility criteria established pursuant to Section 25782 of the Public Resources Code.