Building stock constitutes a huge repository of construction materials in a city and a potential source for replacing primary resources in the future. This article describes the application of a methodological approach for analyzing the material stock (MS) in buildings and its spatial distribution at a city-wide scale. A young Latin-American city, the city of Chiclayo in Peru, was analyzed by combining geographical information systems (GIS) data, census information, and data collected from different sources. Application of the methodology yielded specific indicators for the physical size of buildings (i.e., gross floor area and number of stories) and their material composition. The overall MS in buildings, in 2007, was estimated at 24.4 million tonnes (Mt), or 47 tonnes per capita. This mass is primarily composed of mineral materials (97.7%), mainly concrete (14.1 Mt), while organic materials (e.g., 0.15 Mt of wood) and metals (e.g., 0.40 Mt of steel) constitute the remaining share (2.3%). Moreover, historical census data and projections were used to evaluate the changes in the MS from 1981 to 2017; showing a 360% increase of the MS in the last 36 years. This study provides essential supporting information for urban planners, helping to provide a better understanding of the availability of resources in the city and its future potential supply for recycling as well as to develop strategies for the management of construction and demolition waste. © 2018 by Yale University