This text provides practical, down-to-earth coverage of the non-software aspects of using computerized building energy simulation. While software is the principal tool in the process, the focus of this presentation is on the data needed to build a model, how to build a model, examining the results, diagnosing problems with a model and calibrating them to reality. If you have been frustrated trying to build faithful models of existing buildings, or have become skeptical of the efficacy of building simulation - or are just trying to do a better job simulating buildings - this book should offer you welcome assistance.