Designing lighting for zero-net energy buildings poses unique and fascinating design problems. Beyond the challenge of providing lighting loads on the order of .1W/sqft 2, these projects require toolsets beyond the typical scope of a lighting design consultant, including detailed controls design and photometric predictions of available daylighting. These new roles are part of a broader trend in lighting design as, driven by new code requirements and a general push towards high-performing buildings, lighting design is becoming a more technical, metricsdriven profession. There's a delicate balancing act here, and indeed we have the same responsibility to these projects as any other: lighting that is comfortable and functional for the occupants, that supports the architectural gesture, and that is available within the project budget. So the task is not simply to design the absolute minimum energy density (although yes, also that), but rather to identify ways in which all of these constraints may be harmonized, and embrace the collaborative and iterative workflow that these projects demand.
This case study is written for architects, engineers, owners and others that want an overview of the lighting design process for ultra-low energy density buildings. I'll gloss both the absolute basics and the more esoteric technical details in favor of discussing practical techniques that we used successfully to further the project goals, and the trade-offs we confronted.