In 2024, 73% of new single-family homes started were built on slab foundations, according to NAHB analysis of the U.S. Census Bureau’s Survey of Construction (SOC). Although this was a modest year-over-year increase of 0.6 percentage points, it continues the upward trend in slab adoption, widening the gap between slabs and other foundation types. In comparison, basements (full or partial) accounted for 17% of new homes, while crawl spaces made up just 9.2%. Foundation type continues to follow regional climate patterns. In colder northern divisions, where foundations to extend below the frost line, basements are more common. In 2024, the majority of homes in New England (67.2%), West North Central (62.3%), East North Central (50.3%), and the Middle Atlantic (48.8%) were built with full or partial basements. Among these, East North Central (1,119 sq. ft.) and the Middle Atlantic (1,113 sq. ft.) had the largest average finished basement areas, both exceeding the national average of 1,112 sq. ft. West North Central followed with 940 sq. ft., and New England averaged 810 sq. ft. In contrast, warmer regions favor slab foundations for their affordability and efficiency. Nearly all new single-family homes in West South Central (97.9%), Pacific (89.9%), and South Atlantic (85.7%) divisions were built on slabs in 2024. The cost advantages of slabs have also led to increased adoption in some northern divisions – especially post-pandemic, as rising material costs and supply chain disruptions pushed builders to prioritize cost-effective construction methods. Crawl space foundations have seen a long-term decline. While East South Central and Pacific divisions have historically led in crawl space usage, both have experienced noticeable decreases, particularly the Pacific, which saw a sharp drop in the past decade. Interestingly, the Mountain division has seen a gradual rebound in crawl space use, now ranking second in crawl space share. Meanwhile, divisions such as East North Central, New England, and West South Central have consistently maintained shares of new homes started below 10%, reflecting persistent regional preferences. Notably, the West North Central division surpassed the 10% threshold in 2024 after several years of incremental growth, although it remains unclear whether this marks a lasting shift or a one-time fluctuation. Discover more from Eye On Housing Subscribe to get the latest posts sent to your email.