As the topic and contributors to this Part IV of the book suggest, a twenty-fi rst-century architectural criticism can no longer aff ord to perpetuate false dichotomies between design and performance – 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 benefi ts of spatial organization, new approaches to thermal effi ciency, and especially new means and methods of construction that mitigate GHG emissions and waste.