Eco‐city projects are becoming increasingly prevalent throughout the globe and are often marketed as ‘new’ urban environments focused on achieving sustainable urban living while promoting environmental–economic transitions towards a low‐carbon technological and industrial base. The article argues for the need to consider the thermal aspects of urban metabolism, while at the same time focusing on the link between individual buildings and eco‐city master plans and wider economic development strategies at a state level. In so doing, the article encourages critical analysis of eco‐city design and planning, while keeping a focus on the role of specific building structures within eco‐cities as examples of the intermeshing of what can be termed a ‘political ecology of scale’ which stretches from specific buildings' climatic characteristics, to the metabolic master plan for eco‐cities, to provincial, regional and state‐level plans for the integration of eco‐cities within wider economic and political development trajectories. The article focuses on Masdar, in Abu Dhabi, an eco‐city under construction at the time of writing.