30 January 2016

120 Years of U.S. Residential Housing Stock and Floor Space

Science

Energy consumption in the US residential sector accounts for one-fifth of total energy consumption and energy-related CO2 emissions. Floor space is a major driver of building energy demands. Having access to long-term data is fundamentally important for understanding building energy consumption, as well as the energy efficiency opportunities.

Approach

For that demand, the Department of Energy’s researchers at Pacific Northwest National Laboratory have developed the first consistent, long-term historical time-series of U.S. new construction, housing stock, and floor space. Researchers worked to minimize the effects of the incompleteness and inconsistencies present in the national housing survey data. Over the 1891–2010 period, floor space increased almost tenfold, corresponding to a doubling of floor space per capita. While population increased five times over the period, a 50% decrease in household size contributed toward a tenfold increase in the number of housing units and floor space. However, the research finds that average floor space per unit remains surprisingly constant as a result of housing retirement dynamics. These trends appear to be changing. While household size shows signs of leveling off or even increasing again, over the last 30 years average floor space per unit has been increasing. Gross Domestic Product (GDP) and total floor space show a remarkably constant growth trend over the period and total residential sector primary energy consumption and floor space show a similar growth trend over the last 60 years, decoupling only within the last decade.

Impact

This study indicates that, for the United States at least, the long-term relationship between floor space and GDP has been relatively stable (aside from periods of substantial socio-economic disruption such as the great depression and World War II).

Summary

Residential buildings are a key driver of energy consumption and also impact transportation and land-use. Energy consumption in the residential sector accounts for one-fifth of total U.S. energy consumption and energy-related CO2 emissions, with floor space a major driver of building energy demands. In this work a consistent, vintage-disaggregated, annual long-term series of U.S. housing stock and residential floor space for 1891–2010 is presented. An attempt was made to minimize the effects of the incompleteness and inconsistencies present in the national housing survey data. Over the 1891–2010 period, floor space increased almost tenfold, from approximately 24,700 to 235,150 million square feet, corresponding to a doubling of floor space per capita from approximately 400 to 800 square feet. While population increased five times over the period, a 50% decrease in household size contributed towards a tenfold increase in the number of housing units and floor space, while average floor space per unit remains surprisingly constant, as a result of housing retirement dynamics. In the last 30 years, however, these trends appear to be changing, as household size shows signs of leveling off, or even increasing again, while average floor space per unit has been increasing. GDP and total floor space show a remarkably constant growth trend over the period and total residential sector primary energy consumption and floor space show a similar growth trend over the last 60 years, decoupling only within the last decade.

Contact
Cecilia Moura
Pacific Northwest National Laboratory (PNNL)
Funding
Publications
2015.  "120 Years of U.S. Residential Housing Stock and Floor Space."  PLOS One, doi:10.1371/journal.pone.0134135.
Acknowledgments

This research was supported by the Office of Science of the U.S. Department of Energy Office of Science, Office of Biological and Environmental Research as part of the Integrated Assessment Research Program for the iHESD SFA.