ITU‐T's Technical Reports and Specifications 457 Intelligent sustainable buildings for smart sustainable cities Executive Summary The implementation of intelligent and sustainable buildings is also a key step in the journey to smart sustainable cities. To understand the scale of the issue, buildings are responsible for 40% of global annual energy consumption and up to 30% of all global energy‐related greenhouse gas (GHG) emissions. Also on a global basis, the building sector is responsible for one‐third of humanity’s resource consumption, including 12% of all fresh‐water use, and produces up to 40% of our solid waste. As buildings become more intelligent and more sustainable, there exists the possibility to reduce this impact dramatically. The concept of “intelligent buildings” has been around for a number of years and has relied on the ability of individual systems within the buildings to communicate, to integrate and to perform in a manner allowing for numerous, complex, controls to generate a much‐enhanced response to many kinds of stimuli. Thus, the argument of intelligence can reasonably be associated with the ability of intelligent buildings to function in an enhanced manner yielding many benefits for the occupants, the operators, the owners and reducing the overall environment impact. Definitions of intelligent buildings have been proposed by different user groups and have also evolved during the last few years. Some view the ultimate benefits of intelligence to be the provision of a more efficient and effective working environment for the occupants while others define such intelligence as providing greater economics for the building operators. However, some others conclude that automated responses, in particular to security and emergency situations, are of particular importance. The thesis of intelligent buildings, therefore, is that base building systems can be designed in a manner which permits their intercommunication and which also allows for communication between the building and individual tenant. The benefits are not always the same for each group of interested parties, nor are all the benefits evident when not all buildings include the same features. Intelligent building technologies open the opportunity to facilitate the monitoring of a building's overall condition. Transducers and sensors are available to measure most building related parameters and in any given situation there may be particular needs driving their specific use. The significant advantage of intelligent buildings is that they can constantly monitor current operations in context and automatically adjust resources for optimum efficiency while identifying and accurately informing key decisions in a timely manner. It is the optimization of efficiency that will lead to reduced environmental impact and a more sustainable built environment. It is also evident that the standards applicable to the provision of an IP infrastructure are one possible mechanism by which an intelligent building can be implemented. Depending on the jurisdiction, there may be a need that some of the systems require special considerations in order to comply with all aspects of the building code (e.g., fire safety code or electrical code). Objectives of intelligent buildings have been described in general terms but nevertheless there are often strenuous professional arguments as to what should be the primary objectives of an intelligent building. Is it more important that the building be more efficient, i.e. that the operating costs are reduced or, is it more important that the effectiveness of individual occupants in the building are put as the most important objective.