This Interpretation of Regulations (IR) clarifies specific code requirements relating to battery energy storage systems (BESS) consisting of prefabricated modular structures not on or inside a building for structural safety and fire life safety reviews. This IR clarifies Structural and Fire and. The design and installation shall conform to all requirements as defined by the applicable codes, laws, rules, regulations and standards of applicable code enforcing authorities (latest edition unless otherwise noted). The following are key standards that shall be followed. Think of modern energy storage cabinets.