Basement foundations, once a popular choice in northern states, have been experiencing a decline in popularity across the West and South regions over the past two decades. In this article, we will explore the construction methods, types, pros, and cons of basements and delve into the reasons behind their waning appeal.
Introduction
The National Association of Home Builders says that 65% of all new homes constructed in 2020 had slab foundations, while only 22% of them had full or partial basements and 12% of them had crawl spaces. The gap between these foundations continues to grow. Basements serve the same purposes as other foundation types; they distribute a building’s weight evenly, they secure it into the ground and they keep moisture out.
The most common type of basement construction are:
- Poured concrete. The most common type of basement construction is poured concrete. Forms are used to hold the wall in place as the concrete dries. These can also be poured concrete in ICF or insulated concrete forms.
- Concrete blocks. The least expensive option for basement construction is concrete masonry units reinforced with steel rebar. These walls are faster to construct but are more susceptible to water leaks.
- Precast panels – To save time on site, builders may precast concrete panels in a factory and transport them when they are ready to be installed.
- Stone or clay tile walls – These can be found in older or historic homes. Ground water can seep into the basement fairly easily.
Types of basements
- A full basement matches the perimeter of the house above. Footings usually extend below the frost line, the depth to which the ground freezes in winter. Full basements can be insulated and installed with drywall and flooring, providing living and storage space. They can also be unfinished or uninsulated with bare walls and floors.
- Next are partial basements which have a full height space underground, but do not extend under the entire perimeter of the house.
- Daylight or walkout basements are built when the building rests on a slope: One side of the basement is fully submerged, while the other is aboveground. As the name suggests, daylight basements can have large windows and doors to bring in natural light. They aren’t as susceptible to mold, mildew or moisture.
- Crawl spaces are a type of basement with limited use. Crawl space foundations have a small protected space between the ground and base of the building. They cannot be converted into finished basements, but they provide easy access to piping or plumbing. They also encourage more airflow underneath the building, which helps keep things cool in warmer climates.
- A cellar is a room underground that is often used to store canned goods, fruits, vegetables or wine.
Advantages
- Access to utilities: like plumbing, electrical wires and even under floor ventilation systems. This is a huge advantage over slab foundations where you need to break up the concrete to get to any utilities underneath.
- Repairs and replacements are cheaper and easier with basements.
- Finished full basements can boost home values by increasing the usable footprint. A full basement with a 7 or 8 foot high ceiling can be converted into a home gym, office, play area, home theater, or just left for storage.
- Basements can be energy efficient. They are naturally insulated by the earth so they need less energy to heat or cool rooms.
- Basements also provide shelter incase of a tornado or hurricane so you find yourself in this situation.
Disadvantages
- Cost. In the north there are fewer financial obstacles to basements, making them more prevalent. Basements can also take longer to build and require heavy duty equipment like excavators, cranes, and forklifts.
- Soils play a big role in the feasibility of building basements. There are large areas in the US with clayey soils. Because of the small size of its particles, clay dramatically expands and contracts as it takes on water. This puts immense lateral pressure on basement walls, which would lead to water in the basement even if there was no rain.
- A high water table can also prevent the construction of basements because the soil is extremely damp. Alabama, Louisiana and eastern Texas have a lot of swamp land or wetland territory which are not compatible with basements.
- Climate. When you build a home, the foundations need to be below the depth of the frost line. Northern states have a deep frost line of 60 inches or 5’. They require deep foundations, thus making a basement far more practical. In southern states, the frost line is less than 10 inches below the surface, so there is no need to dip that deep. Basements are an unnecessary and additional expense.
- Risk of leaks, mold and mildew. It’s important to have a sump pump to remove water from your basement. It’s also important to insulate water pipes and keep the foundation crack-free. Missing gutters and downspouts can cause water to puddle and seep into cracks in the foundation.
Conclusion
The decline of basement foundations can be attributed to various factors, including rising construction costs, waterproofing challenges, and changing housing trends. While basements offer unique advantages, such as increased living space and utility access, their drawbacks, such as higher expenses, susceptibility to leaks, and potential mold issues, have contributed to their waning popularity. Homebuyers and builders are increasingly exploring alternative foundation options that align better with their needs and environmental conditions.
Sources
https://mtcopeland.com/blog/3-types-of-basement-foundations-to-know/
https://www.basementguides.com/why-are-there-no-basements-in-some-states/
https://dengarden.com/basements/Why-Dont-Homes-in-Texas-Have-Basements
https://eyeonhousing.org/2021/08/65-of-new-single-family-homes-used-slab-foundation-in-2020/
https://worldpopulationreview.com/state-rankings/frost-lines-by-state
https://earthobservatory.nasa.gov/images/87220/soil-composition-across-the-us
https://www.statista.com/statistics/184902/homeownership-rate-in-the-us-since-2003/
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