This book presents a new approach to whole-life costing and risk management for the construction industry. The options-based approach to making decisions has revolutionised the management of uncertainty in the financial world, and this pioneering study applies the same principles to costing in construction projects. This approach offers a significant advance over conventional costing methods as it considers a diversity of possible futures with strategies that respond to events as they unfold, leading to more cost-effective and sustainable investment decisions across all areas of construction.