Msheireb Properties is revitalizing Doha with an eponymous new downtown that has an ambitious sustainable agenda. Asked to create a master plan for the lighting of the 77-acre development, Arup worked with architectural master planner Allies and Morrison to create standards that are compatible with the desired Qatari building style and minimize the number of illuminated facades throughout the project’s various zones—mixed-use and residential, business, retail, heritage, and government. Employing the LEED light-pollution-reduction credit as a reference, lighting designer Emily Dufner and her team devised a concept called Light, Dark, Light that illuminates rooflines—comprising roof terraces and shade structures—as well as ground-level colonnades with shielded downlights, leaving the facades dark. All of the utilitarian luminaires, such as streetlights, are full-cutoff. LEED does allow a certain percentage of uplighting, however, so allowances were made for landmark buildings, structures on key public spaces, and decorative lighting. In all these cases, controls play a critical role in shutting them off at predetermined times. “Sustainability and the reduction of light pollution is inherent in our approach,” says Dufner, “but in this project, it was client-driven.”