Newly constructed homes in the United States are most likely to be built on a slab foundation, according to the National Association of Home Builders, but basements remain the footing of choice in colder climates.

In analyzing the results of its Survey of Construction, NAHB determined that slab foundations have been increasing in popularity in new single-family homes since 2000. New homes with basements or crawlspaces have become less common in the same period.

Fifty-six percent of all new single-family homes started in 2014 were constructed on slab foundations. By contrast, 28 percent had a full or partial basement and 15 percent had a crawlspace. One percent of new homes were built on another type of foundation, such as raised supports.

Na Zhao, summarizing the results for the NAHB blog Eye on Housing, said climate plays a key role in what type of foundation is used on a home. Since building codes typically require that a foundation be built at or below the frost line, structures in areas with colder winters are more likely to use a basement in order to reach the necessary depth.

Basements were most popular in the West North Central region, which includes seven Midwestern states ranging from North Dakota to Missouri. Eighty-three percent of new single-family homes started in 2014 in this region had a full or partial basement.

In New England, 78 percent of new single-family homes started in 2014 had a basement. The feature was also common in the Middle Atlantic and East North Central regions with 64 percent and 68 percent of homes including a basement, respectively. Half of the new homes in the eight states of the Mountain region also had basements.

Basements were least common in the West South Central region, consisting of four states between Texas and Arkansas, where less than 1 percent of new homes had the feature. Three percent of new homes in the Western region, 13 percent in the South Atlantic region, and 20 percent in the East South Central region featured a basement.

Slab foundations were nearly ubiquitous in the West South Central states, with 96 percent of new single-family homes being built on one. The share was 67 percent in the South Atlantic states.

Zhao says slab foundations are cheaper and easier to build, and better suited for warm climates and clay soils. Despite these qualities, crawlspaces became the more popular option in the East South Central region in 2014.

Slab foundations have also became less popular in the Mountain states, going from a high of 54 percent in 2005 to 39 percent in 2014. Zhao says the difference in geography and climates among different states in the western United States creates a wider variation of foundation types.