Sustainability is the signal challenge of our time, yet we are overlooking the vital role of urban design in confronting this challenge. Most energy debate and investment focuses on supply -- on developing and scaling up new or alternative sources. But in our emphasis on adding supply, we are neglecting a crucial aspect of reducing demand. According to the U.S. Department of Energy, buildings and transportation account for two-thirds of U.S. energy use. This session will highlight place-based research that shows how cities can reduce energy use through the comprehensive adaptation of existing systems, including shelter, transportation, power, water, landscape, and waste. "Existing" is key: our tendency, when faced with obsolete infrastructure, is to abandon what exists and build new -- an unsustainable practice. Speakers from architecture, urban design, and building science will show how diverse factors -- density, land use, multimodal transit, renewable fuels, water and waste conservation, landscape restoration, and building shape, size, material, and orientation -- can be coordinated, modeled, and measured to create resource-efficient (almost zero carbon) districts, reduce urban heat island, and integrate human and natural systems in suburbia. The panel, which will discuss European, Asian, and U.S. research, will argue that effective adaptation must engage not only the scale of components -- such as solar arrays or high-performance materials -- but also the larger scale of urban systems.