Findings shared throughout this report reflect an indepth quantitative assessment of demographic, market, and development trends since the origination of the city’s historic preservation ordinance in 1990. This analysis leverages a geospatial assessment of the geographic coverage areas of Portland’s twelve historic districts using US Census Block, Block Group, and Census Tract data as available. Key data sources include the decennial US Census, building and development permit data provided by the City of Portland, and leading environmental impact calculators cited in this report. Information provided in recent publicly available planning documents supplemented this analysis. A comprehensive range of demographic, housing, real estate, and market indicators were analyzed both individually and collectively across the city’s historic districts, the city’s peninsula, and Portland as a whole. This comparative assessment explored ten-year increments between 1990 and 2020. The analysis tracked impact metrics before the designation of historic districts and after designation, comparing these trends over time with other areas of Portland both with and without historic district designation.