Prices for stone retaining walls are typically given in square feet, and the average prices is between $25 and $40 per square foot, as of 2015. Site conditions, materials used and size also play a role in the final cost of a retaining wall.
The average cost of a retaining wall that is 20 feet long and 30 inches wide ranges from $1,250 to $2,000, but could be higher based on a number of factors. Building a retaining wall out of stone is both a science and an art, so it is difficult to determine the labor costs. Most contractors do not charge a flat fee for building a stone retaining wall; instead they charge an hourly rate.
Stone retaining walls are generally the most expensive option for building a retaining wall. Materials such as wood or concrete typically are less expensive. For instance, an average-sized wooden retaining wall often costs between $1,000 and $1,300, several hundred dollars less than a stone wall of the same size. A concrete retaining wall is usually even less costly, ranging from $750 to $1,500 for an average wall. Other costs, such as permits, engineering costs and even difficulties with site access sometimes cause the installation price to rise as well.