This chapter looks at critical problems encountered in the life prediction of building materials and components, and addresses how a database of life estimates can be compiled for the vast number of component/environment/usage combinations that may exist in a building. Further, it focuses on how an estimate of actual component life can be made for a component subjected to conditions that differ from the reference component in the constructed database. The chapter considers the different uses of life prediction data, and the varying levels of data complexity required for them. The possible methods of deriving life prediction data are analysed in terms of the above research challenges, as well as their applicability to the differing uses of life prediction data. For two methods – Delphi studies and process-based models – detailed case studies are presented.