Share of Homes Built on Slabs Surges to 72.4%
According to NAHB’s analysis of the Survey of Construction (SOC), in 2023, the majority of new single-family homes were constructed using slab foundations (72.4%), followed by those with full or partial basements (16.6%), and crawl spaces (9.9%). The prevalence of homes built on slab foundations has steadily increased from 45.8% in 2000 to 72.4% in 2023. The most significant rise occurred from 2022 to 2023, with a 3.9 percentage point increase, compared to an average annual increase of 1.93 percentage points over the preceding five years. Conversely, the proportion of homes with full or partial basements decreased by 3.0 percentage points, dropping from 19.6% in 2022 to 16.6% in 2023.
According to the NAHB, in colder areas where building codes require foundations to be built below the frost line, most homes are constructed with full or partial basements. In the northern divisions, full or partial basement foundations provide additional finished floor areas at a marginal increase of construction cost. The divisions with a majority share of full or partial basements in new homes are West North Central (63.9%), followed by New England (62.1%), Middle Atlantic (48.1%), and East North Central (48.0%). Interestingly, in East North Central, the share of homes with basements is now almost equal to those with slabs. The average area of finished basement was 1,128 square feet (sq. ft.) in East North Central, 932 sq. ft. in the West North Central division, 890 sq. ft. in New England, and 1,117 sq. ft. in the Middle Atlantic. Nationwide, the average finished floor space of basements was 1,113 sq. ft. in 2023.