There is a vast amount of publication on the design of high-performance buildings; there is much less data available for reliable, operational data that has been measured and reported in a consistent format. The NABERS (National Australian Building Environmental Rating Scheme) now has data spanning almost 20 years, for a database of about 2,000 buildings, with many buildings having been rated repeatedly, some more than 10 times. Team Catalyst, has been helping deliver high-performance commercial office buildings that have achieved, and then maintained, a high level of performance. In this presentation, the main points of NABERS and present selected case studies on how Team Catalyst assisted in the design, review, and delivery of high-performance buildings, using dynamic energy simulation and practical experience.