For purposes of this section:
(a) “Joint powers authority” means the agency or entity designated or created pursuant to a joint powers agreement between the Office of Emergency Services and the Department of Forestry and Fire Protection, entered into pursuant to Section 8654.4, to implement this article.
(b) “Structure hardening” means the installation, replacement, or retrofitting of building materials, systems, or assemblies used in the exterior design and construction of existing nonconforming structures with features that are in compliance with Chapter 7A (commencing with Section 701A.1) of Part 2 of Title 24 of the California Code of Regulations, or any appropriate successor regulatory code with the primary purpose of reducing risk to structures from wildfire or conforming to the low-cost retrofit list, and updates to that list developed pursuant to paragraph (1) of subdivision (c) of Section 51189.