Between 2008 and 2011 members of the Concrete Coalition completed numerous building inventories of California cities to assemble a database of California pre-1980 concrete buildings. Inventory collectors used a variety of data sources ranging from county assessors files to Sanborn maps and satellite images. Sidewalk surveys were used to corroborate data collected from multiple sources, and a regression model was developed to extrapolate data to cities where detailed inventory collection was not possible. Lessons drawn from inventories of three cities – Alameda, Los Angeles, and San Francisco – indicate that no single approach can be recommended, but instead the approach depends on many things including city size, building stock, available budget, available data, and availability and experience of human resources. Regardless of approach, inventory data is a valuable resource for developing loss estimates and policy recommendations.