EVOLUTION of LOS ANGELES'
BUILDING INFRASTRUCTURE

Building stocks constitute enduring components of urban infrastructure systems, but little research exists on their residence time or changing environmental impacts. Using Los Angeles County, California as a case study, a framework is developed for assessing the changes of building stocks in cities (i.e., a generalizable framework for estimating the construction and deconstruction rates), the residence time of buildings and their materials, and the associated embedded environmental impacts. In Los Angeles, previous land use decisions prove not easily reversible, and past building stock investments may continue to constrain the energy performance of buildings. The average age of the building stock has increased steadily since 1920, and more rapidly after the post-WWII construction surge in the 1950s. Buildings will likely endure for 60 years or longer, making this infrastructure a quasi-permanent investment. The long residence time, combined with the physical limitations on outward growth, suggests that the Los Angeles building stock is unlikely to have substantial spatial expansion in the future. The construction of buildings requires a continuous investment in material, monetary, and energetic resources, resulting in environmental impacts. The long residence time of structures implies a commitment to use and maintain the infrastructure, potentially creating barriers to an urban area’s ability to improve energy efficiency. The immotility of buildings, coupled with future environmental goals, indicates that urban areas will be best positioned by instituting strategies that ensure reductions in life-cycle (construction, use, and demolition) environmental impacts.

Janet Reyna and Mikhail Chester, 2015, The Growth of Urban Building Stock: Unintended Lock-in and Embedded Environmental Effects,
Journal of Industrial Ecology, 19(4), doi: 10.1111/jiec.12211.