To standardize calculations and to provide a basis for presenting the prescriptive requirements, the Energy Commission has established a set of standard climate data for each of the 16 climate zones. More information is provided in Joint Appendix II, including a listing of climate zones for all California cities. Joint Appendix II gives other climate information such as design temperatures for sizing HVAC equipment. The climate zone definitions and data are the same for both the low-rise residential and the nonresidential standards. Cities may occasionally straddle two climate zones. In these instances, the exact building location and correct climate zone should be verified with the building department or by the person preparing the compliance documentation before any calculations are performed. If a single building development is split by a climate zone boundary line, it must be designed to the requirements of the climate zone in which 50% or more of the dwelling units are contained.