Excavation in Denver: local operators and what it costs
Excavation around Denver covers footings for additions and garages, basement and crawlspace digs, window wells, retaining wall cuts and site leveling. Two local conditions shape the work: a frost line three feet down and clay that swells and shrinks with moisture. This page covers both, the city's permit thresholds for larger disturbance, right-of-way rules, the Colorado 811 notice, and a typical local cost for residential excavation.
Paid member operators who cover the region see your project and can contact you directly, and annual members get an instant email alert.
What excavation costs in Denver
$2,650 to $19,050 for most residential digs
Based on Pro Operator Network's national excavation cost guide, checked against published cost guides, and adjusted to the Denver-Aurora-Centennial metro area using its 2024 price level from the U.S. Bureau of Economic Analysis (105.8, where the U.S. average is 100).
A typical range, not a quote. Your own price depends on your property and is set by whoever takes on your project.
Footings below the frost
Denver's building code puts the frost line at thirty-six inches below finished grade, so footings and other frost-sensitive work go at least that deep. A Denver footing dig is deeper than one in the South, with more spoil to handle for the same footprint.
Expansive clay
The Colorado Geological Survey describes the montmorillonite clays common in this region as able to expand by up to a fifth of their volume when wet. Builders often over-excavate and replace such clay or design around it, and CSU Extension notes that all major Colorado population centers are partly on expansive soils. If a soils report exists for the lot, it should guide the depth and backfill.
Permits by size
Construction that disturbs an acre or more needs a construction stormwater discharge permit in Denver, and a drainage report may be required when grading changes cover more than half an acre. Work in the public right-of-way, such as a new curb cut or sidewalk replacement, needs a permit from the City Engineer.
Weather and the open hole
Summer thunderstorms on the plains can be extremely heavy, according to the Colorado Climate Center, and wet clay at the bottom of a dig swells. Keep excavations covered or pumped and pour or backfill without long gaps.
Colorado 811
Colorado law requires notice to Colorado 811 at least two business days before excavating, not counting the day of notice, and marks are valid no longer than thirty calendar days after the due date. Private lines are the owner's to locate.
For your project post
Describe what is being dug, its size and depth, whether a soils report or plan exists, where the spoil goes, how a machine gets in, and any permit already in hand.
Run equipment in Denver?
5 operators on Pro Operator Network cover Colorado.
Own a excavator in Denver? This is what people here pay for this job. Join free and get these projects.
Join free