Analysis finds older homes dominate U.S. housing stock and present the greatest opportunity for efficiency gains

[ST. PAUL, MINN.] Housing Affordability Institute released a new report today, Chasing Perfection: Energy Performance in the Nation’s Aging vs. New Housing Stock, examining how energy efficiency varies across housing built over the past several decades.

To better understand how energy performance has evolved, the Institute commissioned an independent energy code and engineering consultant to compare model homes built today with those constructed 30 years ago. The analysis examined housing across five distinct climate zones: Phoenix, Arizona; Dallas, Texas; Asheville, North Carolina; Spokane, Washington; and Minneapolis–St. Paul, Minnesota.

Across all regions studied, older homes make up the largest share of housing—and consistently perform the poorest in terms of energy efficiency.

• New homes are more efficient—but limited in impact. Across the U.S., less than 14% of housing has been built since 2010, meaning the vast majority of homes were constructed under older, less stringent energy standards.
• Older homes dominate energy use. The analysis shows new homes improve in performance due to energy codes, but remain a small part of housing, with older homes responsible for most energy use, offering the greatest efficiency gains.
• Flat natural gas usage signals limited impact from new construction policies. Despite population and housing growth, residential natural gas use has remained relatively stable for decades.  

“New homes are delivering measurable gains in energy efficiency, but they make up a small portion of the overall housing stock,” said Nick Erickson, executive director of Housing Affordability Institute. “If policymakers want to meaningfully impact energy use, the data shows the focus must expand to include existing homes. This is especially pronounced in slower-growth markets.”

The findings highlight two central policy considerations. First, improving the performance of new homes continues to raise standards, but addressing the existing housing stock may play a larger role in achieving broad efficiency outcomes. Second, discussions surrounding reducing natural gas consumption should focus on the segments where natural gas utilization sees significant growth.