Since the 1960s, wind tunnel testing has become a commonly used tool in the design of tall buildings. It was pioneered, in large part, during the design of the World Trade Center Towers in New York. Since those early days of wind engineering, wind tunnel testing techniques have developed in sophistication, but these techniques are not widely understood by the designers using the results. As a direct result, the CTBUH Wind Engineering Working Group was formed to develop a concise guide for the non-specialist. The primary goal of this guide is to provide an overview of the wind tunnel testing process for design professionals. This knowledge allows readers to ask the correct questions of their wind engineering consultants throughout the design process. This is not an in-depth guide to the technical intricacies of wind tunnel testing, it focusses instead on the information the design community needs, including: A unique methodology for the presentation of wind tunnel results to allow straightforward comparison of results from different wind tunnel laboratories. Advice on when a tall building is likely to be sufficiently sensitive to wind effects to benefit from a wind tunnel test. Background for assessing whether design codes and standards are applicable. Details of the types of tests that are commonly conducted. Descriptions of the fundamentals of wind climate and the interaction of wind and tall buildings. This unique book is an essential guide for all designers of tall buildings, and anyone else interested in the process of wind tunnel testing for tall buildings.