The average cost of excavation is approximately $3,200, with typical projects ranging from $500 to $15,000. Depending on the contractor, you may be charged between $50 and $200 per cubic yard or an hourly rate of $40 to $180 for an excavation specialist. The total cost is influenced by several factors, including the project size, the amount of soil to be removed, and the soil's condition. Hard soil, tree roots, or excessive rocks and clay can increase the price, potentially adding $200 to $1,200 to the final bill. Other factors that can drive up costs include the presence of nearby structures that complicate the work or tight spaces that require manual excavation instead of heavy machinery.

Excavation is priced in cubic yards, so you’ll need to find the volume of the area in order to calculate costs. Multiply the length, width, and proposed depth of your excavation site, then convert it into yards to get the volume. Multiply this figure by the price per cubic yard.

Most homeowners can measure by hand to get a rough estimate, even if it’s tedious. You may want to pull out a tape measure or use a string to help mark the area.

Slab foundations are more affordable than crawl spaces because they require minimal excavation, as the slab sits directly on the ground or on footers that only sink a few feet into the ground. Crawl spaces require excavation of the entire footprint of the home to several feet below the surface. Not only does that mean higher labor costs, but more materials are necessary for the concrete foundation walls.

The best type of soil to build on is a mixture of sand and clay, known as loam soil. Loam soil has the best combination of these soil types to build a foundation on. The clay particles help with water retention, so it won’t erode like sandy soil might, and the sandy particles help with drainage, so you won’t see unsafe soil expansion or have an increased risk of leaks from water sitting against your foundation.