The Rise of Slab Foundations in New Home Construction
In 2023, the construction landscape for new single-family homes saw a significant shift towards slab foundations, marking a clear trend in residential building practices. According to an analysis by the National Association of Home Builders (NAHB) based on data from the Survey of Construction (SOC), slab foundations became the dominant choice, with 72.4% of new homes built on this type of foundation. This represents a steady increase from 45.8% in 2000, highlighting a growing preference for slabs over the past two decades.
The most notable change occurred between 2022 and 2023, with the share of new homes built on slabs jumping by 3.9 percentage points—a significant rise compared to the average annual increase of 1.93 percentage points over the previous five years.
Decline in Basements and Crawl Spaces
As slab foundations gained popularity, the share of homes with full or partial basements continued to decline. In 2023, only 16.6% of new single-family homes were constructed with basements, down from 19.6% in 2022, marking a 3 percentage point decrease. Additionally, homes built with crawl spaces have become increasingly rare, with just 9.9% of new homes utilizing this foundation type in 2023.
Regional Preferences: Climate and Building Codes Drive Foundation Choices
The choice of foundation type is heavily influenced by regional climate and local building codes. In colder regions, where building codes require foundations to extend below the frost line, full or partial basements are the preferred choice. These basements not only comply with frost line requirements but also provide additional finished floor space at a relatively low additional cost. The regions with the highest percentage of new homes built with basements in 2023 include the West North Central (63.9%), New England (62.1%), Middle Atlantic (48.1%), and East North Central (48%) divisions.
In contrast, in warmer climates where the frost line is not a concern, slab foundations are favored for their cost-effectiveness and simplicity. Slab foundations are particularly prevalent in the West South Central (96.9%), Pacific (86.5%), South Atlantic (83.3%), and Mountain (52.9%) divisions.
The trend towards slab foundations in new home construction reflects broader changes in building practices, driven by factors such as climate, cost, and regional building codes. As these trends continue to evolve, slab foundations are likely to remain a popular choice, especially in warmer regions, while basements will continue to be favored in colder areas where they offer both practicality and added living space.
