More Houses Are Being Built on Slab Foundations

To make housing more affordable, home sizes are shrinking and builders are also forgoing basements in many parts of the U.S. According to recent analysis by the National Association of Home Builders, the share of new homes built on slabs has risen steadily from 45.8% in 2000 to 72.4% in 2023. At the same time, 16.6% of new homes were built with full or partial basements, and 9.9% were built with crawlspaces.

In warmer climates where slab foundations are preferred for their cost-effectiveness, new homes with slab foundations are most commonly found in the West South Central (96.9%), Pacific (86.5%), South Atlantic (83.3%), and Mountain (52.9%) divisions. However, adoption rates for slab foundations are also increasing in northern divisions. The figure below shows the share of slab foundations for these four divisions have risen from less than 15% in 2000 to over 30% in 2023. Notably, there is a knee in the curve in 2020, indicating that supply chain disruptions and building material prices brought about by the pandemic contributed to the switch to slab foundations. Another factor is the increased use of frost-protected shallow foundations (FPSF), introduced in 2000, that also enhances affordability.

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