The Cities of Repetition project provides a comprehensive graphic documentation and analysis of the largest Hong Kong housing estates built by private developers from the late 1960s through the early 2000s. The original drawings and diagrams illustrate and compare the ultra-dense, mass-produced, highly repetitive built environments in which hundreds of thousands of Hong Kong residents live. Drawings, diagrams and photographs not only display the immense scale of the housing estates within the city, but also present the hundreds of similarly planned housing units and their subtle differences. Detailed diagrams compare statistical information to show how the planning of these massive estates has evolved over the past decades to efficiently conform to building regulations. The publication and larger research project present a comprehensive analysis of the architectural and spatial realities of some of the most densely populated, urban environments ever built.