This chapter suggests a twenty-first-century architectural criticism can no longer afford to perpetuate false dichotomies between design and performance and explains judgment of the quality of the former increasingly requires evaluation of the measurement of the latter. Nowadays, premier architects tout rigorous carbon-management protocols, sustainable technologies, user surveys, and operational accountability as the principal highlights of novel form and spatial organization. Measurable carbon management is increasingly unavoidable among primary high design criteria, even in awards programs traditionally oriented toward visual and aesthetic achievement. As a consequence, architects and builders are testing new materials, new mechanical equipment, new approaches to the health benefits of spatial organization, new approaches to thermal efficiency, and especially new means and methods of construction that mitigate GHG emissions and waste. The US Green Building Council established the Leadership in Energy & Environmental Design (LEED) accreditation system to promote sustainable practices in the building industry.