This book presents a collection of essays related to urban infrastructures current state of transition, basically represented by the change from centralized to potentially decentralized, and from passive to smart infrastructures. This transition opens new landscapes to understand relationships between providers, users and regulators, drawing a more complex governance of urban fabrics and urban services delivery. In this context, the book examines the expanding role of intermediaries that take part in these changing relationships in most of the crucial sectors to understand cities: energy, water, waste and building.

Intermediaries here stand for a range of different actors working in-between production and consumption in urban services and the book describes some examples of how these intermediaries are acting, from NGOs involved in promoting energy labeling schemes to public-private agencies working on developing water expertise in urban economic systems. From this point of view, some chapters are a good mean to understand how governance is evolving in urban policies, on the assumption that some general patters are reconfiguring socio-technical networks. Urban infrastructures in transition are characterized by the shift in the balance of power from liberalization and privatization of urban services and infrastructures, but also by changes in consumption patterns, increase in environmental regulation and research on technological innovation. Liberalization of European markets for electricity and gas, privatization of utility companies are creating new actors and boundary organizations emerging in this new context, environmental concerns are increasing regulatory powers of public agencies, new consumption patterns -such as the drop of water consumption and increasing demand for renewable energy- create new challenges for infrastructures and, finally, technical diversification widening the way urban services are delivered (think of small-scale technologies for electricity), are the main trends that draw this transition allowing the emergence of intermediaries.

This perspective is a brilliant way to take into account the role of institutions in current urban governance and to try to understand the diversification of actors mediating between infrastructures, nature, cities, regulators, providers and consumers. As a collection of essays, some chapters raise deserve more attention that others depending of the reader´s interests and probably they can only serve as indicative of the variety of intermediaries but, at least, most of the core urban services are covered. Probably, urban traffic may be the biggest missing sector, but the rest of them (green electricity, technology solutions for wastewater, privatization of wastewater public utilities, strategy, vision and urban leadership, zero-carbon building regulations, smart metering,...) are covered as case studies.