Embarking on a library space planning odyssey is exciting, terrifying and all absorbing. Planning a new library building or a major refurbishment is a challenging process requiring a strong strategic vision, attention to detail, excellent communication and an element of crystal-ball gazing. This article, written by Karen Latimer, examines the changing typology and current trends in library building design which help planners to envisage the future library and make informed decisions. These trends include the move from collections to connections, the need for varied and flexible learning spaces, sustainability, the impact of technological developments, and the need for scholarly research centres amongst others. Examples of recent library projects are cited to provide inspiration and illustrate the points made. The planning process required to brief the design team effectively and to achieve a successful outcome is considered as is the key role of post-occupancy evaluation in ensuring a continuous loop of improvement. To conclude resources available to provide support are described.