Amendment #LEED 2.0-EAc1-133 allows California Title-24 to be used in place of ASHRAE 90.1-1999 to evaluate the number of points that can be earned for LEED credit EAc1. In California Title-24, lighting for spaces including hotel/motel guest spaces, dormitory living space, and high-rise residential living space is treated as an unregulated load, where lighting power density is always modeled at 0.5 Watts per square foot in both the standard and proposed case. (Note that California Title-24 does prescriptively require efficient light fixtures to be installed in kitchens and restrooms for all of these spaces). Lighting for corridors, lounges, lobbies, and any other space functions for hotels, motels, dormitories, and high-rise residential buildings is counted as a regulated load in Title-24, with specific lighting power density limits and the ability to propose lower lighting power for the proposed case. For residential living spaces, where lighting power density is not regulated by Title-24 and is required to be modeled identically in the standard and proposed case, should the lighting energy be separated out in post-processing in the same ways as other unregulated loads (such as plug loads, process loads, etc.) when calculating the LEED EAc1 points?
Exception b in ASHRAE 90.1 Section 9.1 specifically exempts "lighting within living units" from regulation, and, as pointed out in this CIR, Title-24 also exempts these loads. The Reference Guide classifies non-regulated components as "miscellaneous energy uses in the building for which the standard does not contain requirements." Since lighting for residential spaces is considered a non-regulated load according to the reference standards, it must be deducted from the LEED ECB calculation. Lighting power densities and assumed schedules of operation still need to be estimated carefully, included in the energy model to simulate HVAC requirements, and documented sufficiently in the credit application.