The drive for energy efficiency arising from a growing awareness of the dangers of climate change is leading to new approaches to library design. The article explores the interaction between library architecture and sustainability by reviewing the many complex strategies employed for saving or recycling evermore scarce natural resources. Although the focus is upon energy consumption, the article also investigates how concepts of comfort and climate are changing under the impact of environmental sustainability. These topics are discussed mainly in the context of public and university libraries built over the past decade, with some reference to library designs still awaiting construction. The methodology is developed primarily throu...