With the current rapid depletion of non-renewable resources to generate power; energy conservation and on site generation have become the most critical aspects of the equation. Buildings should be so designed or retrofitted in order to generate its own electricity and cater to its own demand. This book looks at the ways in which we can do a post occupancy analysis of an existing institutional building of about 95,000 square feet that was built in 1960’s in order to reduce usage and approach a Zero Net Energy goal. This case study is located at the heart of USC (University of Southern California). It is challenging to retrofit an existing institutional building because of its complexity and make it achieve a ‘Zero Net Energy’ goal. The process including roadblocks, real life delays, software limitations that had to be overcome to achieve this result are explained in this book. The Zero Net Energy goal was achieved by calibrating energy model to the utility data of the building, providing various energy efficiency measures and generating on-site electricity. This book is especially useful for energy professionals, academicians preaching sustainability and curious building owners.