Inspired by the multi-functional performance of a shell structure in nature, the design of this two-bedroom, two-bath ADU explored a performance-based roof geometry that becomes the building façade and privacy screen. Coupled with deep roof overhangs, this second skin allows dappled light to penetrate the interior during the day while reflecting the detrimental UV radiation on the southern exposure. The perforations in the second skin are based on the effects of the sun path on the southern exposure and the location of the windows behind the screen. At night, the interior light glows through the perforations, contributing to the name of the project, “LuminOCity”. Orange Coast College and UC Irvine formed a partnership called "Team MADE" to enter the 2023 Orange County Sustainability Decathlon. "MADE" is an acronym for Modular, Affordable Dwellings for the Environment. LuminOCity won second place in the competition and 9 awards in various categories. Following the competition, the home was donated to Homeless Intervention Services, Orange County, where it serves as an ADU on an existing property to provide transitional housing for youth experiencing housing insecurities. This 750sf prefabricated, modular home is built on four, eight foot wide modules that nest together. The building system is predicated on a software-to-manufacturing pipeline called the FrameCAD Machine. This roll-former for light-gauge steel allowed Team MADE to prototype as well as site-manufacture every stud and track in the steel-framed home they would design. Over 100 student volunteers aided in the construction of the steel framing, MEP installation, building envelope, and site work. The use of prefabricated Light Gauge Steel allowed for higher construction tolerances with simplified assembly diagrams that could be followed by student volunteers. Joseph Sarafian, AIA was the lead architect as well as one of four faculty advisors on the project, leading the design of the project from conception to completion.