A set of salient architectural features for the interior volumes of houses of worship and performance spaces was selected. These features include volume, height, length, width, number of audience seats, type of plan, and predominant material. The buildings were chosen to illustrate a broad range of types within these two categories; well-known examples are included as benchmarks. Data were taken from the literature and entered into a database. With a descriptive statistics program, these data can be inspected from various perspectives. The purpose of this study is to allow a designer to enter features of a proposed design, and by inspection to get a sense of where the design lies in relation to existing buildings. For instance, a proposed church may have important similarities with an existing concert hall. Future plans include access to drawings and acoustical measurements (if available) for each building included, and posting on the World Wide Web with forms for collecting new data.