The potential of cities in leveraging energy transformation is increasingly recognised, with a growing focus on urban built environments. In this paper we focus on smart building energy management as an increasingly pivotal material means through which energy transformation comes to matter in cities, and through which buildings are politicised in the negotiation of energy transformation. We advance a material political analysis of the case of Sydney's premium commercial office building sector to explore how such buildings are conferred with political capacity. We explicitly extend this material politics framework to pluralise the ‘whereabouts’ of the politics of energy transformation, expanding recognition of the sites and moments of negotiation through which these politics are enacted, authority shaped, and where trajectories of energy transformation begin to be fashioned. Drawing on this extended conception of politics, the paper traces how the political capacity of buildings comes to matter through smart building energy management platforms as they are negotiated through the context of Sydney's policy settings, the political-economy of the top tier commercial office sector, and building management cultures. We conclude with observations on how smart building energy management platforms might contribute to the shaping of particular trajectories, possibilities and limits for energy transformation advanced through the built environment.