Regardless of the architectural style, a house is only as good as its foundation, which supports the floors, walls, and everything that comprises the structure. A strong foundation is essential for the safety and longevity of any building. The type of foundation contractors use during the construction of structures varies depending on the style of the building, its geographical location, construction permits, and the construction timeline. The two most commonly used foundation types are slab foundation and crawlspace foundation.

What is a Crawlspace Foundation?

A crawlspace foundation is a type of foundation that has a floor and concrete walls, with the walls being at least 45cm in height above the ground. It allows access to the area after the house’s construction. Typically, heating systems, plumbing, and other wiring infrastructure are installed in this space. These crawl spaces, defined as the area between the ground and the first floor of the house, are 0.6 to 1.2 meters in height.

You can access the crawl space from the basement if the ground level is the same as the basement level, or from an entrance outside the house. With the addition of flooring, interior walls, and ventilation, this area can also serve as a storage space.

Slab vs. Crawlspace Foundations

The two most commonly used foundation types in newly constructed homes are slab and crawlspace foundations. In a slab foundation, the structure is built on top of a thick, level concrete slab, whereas in a crawl space foundation, exterior concrete walls elevate the foundation by at least 45cm and create access space for wiring infrastructure, plumbing, and storage.

When compared to other foundation types, slab and crawlspace foundations are a more economical choice. They are also suitable for various regions, soil structures, and climate conditions.

Crawlspace Foundations Pros and Cons

The pros and cons of crawlspace foundations vary based on the area where construction takes place, as it is better suited for certain soil conditions. Therefore, once you’ve determined the location where you will build your home, you will make your decision considering the pros and cons we’ve outlined below.

The Pros of Crawl Space Foundations

Suitable for Sloped Lots

Crawl spaces are commonly used on uneven or sloped terrains. This is because a crawl space foundation can be elevated sufficiently to create a level construction surface without the need to flattening out the terrain.

Easy Access to Plumbing or Wiring

Crawlspace foundations permit for plumbing, gas pipes, and electrical cords to be positioned within the gap between the ground and the floor of the home. This enables easy access for maintenance. As a result, maintenance and repair costs are significantly reduced.

Reduces Renovation Costs

Compared to gas lines and utilities embedded in slab foundations, crawlspace foundations provide much easier access to these systems. This simplifies and reduces the cost of renovation projects.

The Cons of Crawl Space Foundations

Requires Monitoring and Maintenance

Crawl spaces are often damp, dark, and poorly ventilated, creating a suitable environment for mold, moisture, and pests. If not monitored, this can lead to significant foundation issues. For this reason, crawl spaces are not preferred in areas with high humidity or rainfall.

More Expensive

Compared to slab foundations, crawlspace foundations are more complex in structure and thus more costly. The average cost of a crawl space foundation is more than two and a half times that of a standard slab foundation.

Shorter Lifespan

The materials used in constructing crawlspace foundations and the increased likelihood of issues such as mold and decay result in shorter lifespans for these foundations. However, with proper maintenance, a crawl space foundation can still endure for the entire lifespan of the building.

Slab Foundations Pros and Cons

The commonly used slab foundation consists of a thick concrete layer. There is no access underneath this layer, and all plumbing is built within or on top of it. When considering the slab foundation option for your home, consider the pros and cons we explain below.

The Pros of Slab Foundation

Quick to Construct

Slab foundations are poured as a single block. The slowest part of the process is usually leveling the ground. Afterward, things progress rapidly. Due to this efficiency, slab foundations are often favored in high-volume constructions.


Constructing slab foundations is cost-effective. Additionally, their durability and low maintenance requirements lead to long-term savings.


Constructed with concrete and reinforcing bars, slab foundations are highly sturdy and long-lasting. They also exhibit resistance to issues like mold, moisture, pest damage, and more.

The Cons of Slab Foundation

Cannot Be Built on Sloped Areas

The ground where a slab foundation is to be constructed must be completely level. If you are building on a sloped terrain, a slab foundation cannot be an option.

No Extra Space

Due to being directly built on the ground, there is no room for plumbing, gas pipes, or storage beneath slab foundations. These systems are typically embedded within the foundation. As a result, accessing these infrastructure elements increases costs.

Not Suitable for Cold Climates

Standard slab foundations are not suitable for cold climates as they are more prone to cracking or breaking due to freezing and thawing of the ground. However, frost-protected slab foundations perform well in cold climates.

Things to Consider

When deciding between a slab foundation or a crawl space foundation, you should take into consideration the factors we explain below.

1. Winter

Knowing how the winter season plays out in the area where you will construct your home is essential, as cold weather can inflict significant damage on construction. For instance, extremely low temperatures can lead to the cracking of slab foundations.

Being prepared for winter conditions and pouring concrete correctly are important for both foundation types. Additionally, you’ll greatly benefit from working with an experienced team.

2. Energy-Efficiency

You can add heat lamps under crawlspace foundations since they allow more air to pass through. However, instead of taking such measures for energy efficiency, you might also consider constructing a slab foundation.

Installing air and moisture barriers in a crawl space foundation will greatly benefit you in terms of energy efficiency; be sure not to overlook this aspect.

3. Maintenance

Compared to slab foundations, these space foundations require much more maintenance. It is recommended to check for any issues in crawlspace foundations on a monthly or bi-monthly basis.

If you don’t want to do this yourself or if you think you might forget, you can consider hiring a team to do it for you.

4. Price

Crawlspace foundations are considered high-end foundations, and you pay not only for the slab but also for additional processes. Therefore, they are more expensive than slab foundations.

Although in cases where a crawl space foundation is necessary, extra costs are minimized, remember that it will still come at a higher expense for you.

5. Moisture Level

Keep in mind that moisture can damage foundations and consider this when building your home.

In excessively humid areas, crawlspace foundations can foster the growth of mold, fungi, and bacteria in these spaces. Additionally, crawl spaces can become incredibly muddy and undesirable for any repair work if a problem arises.

Choosing the Best Foundation Style

In cold, dry climates and on sloped or hilly terrains, crawlspace foundations are the best foundation option. Properly ventilating and heating the crawl spaces prevents moisture buildup and other potential issues. If it fits your budget and the construction site well, opt for a crawl space foundation.

Okan Ergin

Okan Ergin

Okan Ergin has been working as the General Coordinator at Ergin Makina since 2005.