The required depth of a helical pier is a primary factor in determining its cost, as it directly correlates with both material and labor expenses. Because piers must extend past active soil zones to reach stable load-bearing strata, deeper installations require higher investments.

According to the provided guide, depth affects the price in the following ways:

• Incremental Costs: Each additional foot of depth typically adds $30–$50 per pier. This increase covers the cost of longer steel shafts and the extended machine time required for installation.
• Project Scope: In regions like Colorado, varied geology may require piers to exceed depths of 20 feet to reach competent soil, which significantly multiplies the per-pier investment compared to shallower installations.
• Soil Influence: Difficult soil conditions, such as expansive clay or loose fill, often demand deeper placement or larger helix plates. These conditions can increase overall costs by 15–25% due to the specialized equipment and torque levels needed to reach the necessary depth.

While general pricing for residential projects in Centennial typically falls between $1,500 and $3,000 per pier, the final cost is highly dependent on the specific depth confirmed during a geotechnical evaluation or on-site assessment.