Do I Need a Permit for a Deck in Aurora, CO?

Aurora's combination of a 36-inch frost line, 25-lb-per-square-foot ground snow load, and high-elevation UV intensity means the city takes deck structural compliance seriously. The Aurora Building Division requires permits for virtually all deck construction—and inspectors check footing depth at rough framing, not just at final.

Aurora deck permit rules — the basics

The Aurora Building Division, located at 15151 E. Alameda Parkway, Suite 2400, Aurora CO 80012, administers all residential deck permits under the 2021 International Residential Code as locally adopted. Chief Building Official Dave Schoonmaker's office processes permit applications through the city's Aurora4Biz online portal or in person at the permit counter. Staff can be reached at 303.739.7420 or by email at permitcounter@auroragov.org.

Aurora's permit fees for decks are calculated against the project valuation rather than a flat rate. The city uses the ICC Building Valuation Data table as its reference; deck valuation is calculated at 50% of the local private-garage square-foot cost, which typically places a 300-square-foot pressure-treated deck at a valuation of roughly $7,500–$9,000. At that valuation range, the permit fee runs approximately $130–$160, and the plan review fee (billed separately at roughly 65% of the permit fee) adds another $85–$105, bringing the total government fees to approximately $215–$265. A larger composite deck valued at $20,000–$30,000 will generate total permit-plus-plan-review fees closer to $350–$500. These figures do not include Arapahoe County use tax, which applies at the county rate on materials.

Plan review timelines are typically 10–15 business days for standard residential decks. Aurora processes permit applications electronically through Aurora4Biz.org; homeowners and contractors upload a site plan, construction drawings showing footing locations and dimensions, beam and joist span tables, and a project valuation estimate. If the deck is attached to the house, the ledger board connection detail must be shown on the drawings. Aurora inspectors conduct two required inspections for most decks: a footing inspection before concrete is poured, and a final inspection after all work including railings, stairs, and decking is complete.

Aurora has adopted the 2021 IRC with local amendments. Under that code, any deck surface more than 30 inches above grade requires a guardrail of at least 36 inches in height with balusters spaced no more than 4 inches apart. Stairs require handrails on at least one side if there are four or more risers, with risers between 4 and 7.75 inches and treads at least 10 inches deep. For attached decks, the ledger board must be through-bolted or lag-screwed to the house framing—no face-nailing is accepted—and must be flashed with an approved waterproof barrier to prevent moisture intrusion at the wall.

Why the same deck in three Aurora neighborhoods gets three different outcomes

Aurora spans parts of Arapahoe, Adams, and Douglas counties, covers roughly 163 square miles, and contains dozens of master-planned communities—many with active HOAs that layer their own design review on top of city permitting. Two homeowners with identical decks a mile apart can face dramatically different paths to completion depending on their specific lot's variables.

Aurora's 36-inch frost line — why it's the single biggest structural driver

At an elevation of roughly 5,471 feet above sea level, Aurora experiences ground freezing that penetrates deep into the soil each winter. The Colorado Front Range frost line—adopted in Aurora's local building code—is 36 inches below finished grade. This is not a suggestion; it is a minimum enforced through the footing inspection that Aurora inspectors conduct before any concrete is poured. If footings are not at 36 inches of depth at the time of inspection, the inspector will stop the job and require excavation to the proper depth before concrete is placed.

What this means in practice is that every deck post in Aurora must be supported by a concrete pier or spread footing that extends at least three feet below the surface. Many builders use tube forms (Sonotubes) filled with poured concrete, but helical screw piers have become increasingly popular in Aurora for their speed of installation and their ability to anchor in the expansive clay soils common throughout the city. Expandable post bases that allow posts to be set after the footing cures are acceptable under the 2021 IRC and are commonly used in Aurora; they eliminate the footing-to-post alignment issues that plague wet-set post installations. The key inspection requirement is that the inspector must see the bottom of the excavation—or a signed engineer's letter confirming depth—before any concrete is placed.

Frost heave on un-permitted, under-depth decks is a real problem in Aurora. When deck footings sit above the frost line, the freeze-thaw cycle pushes the posts upward each winter and allows them to settle unevenly each spring. Over five to ten winters, this cyclical movement cracks ledger connections, splits decking boards, and creates trip hazards on stair stringers. Aurora code inspectors have seen the aftermath of shortcuts enough times that they are particularly vigilant about footing depth at rough-framing inspections. Bringing in a deck with shallow footings for the final inspection—hoping the inspector won't ask—is a gamble that rarely pays off; final inspectors routinely ask for documentation of the footing inspection sign-off card before approving the final.

What the inspector checks in Aurora

Aurora building inspectors conduct a minimum of two site visits for most residential deck projects. The first, the footing inspection, happens after excavation is complete and forms are placed but before any concrete is poured. The inspector measures the depth of each footing hole, verifies that hole diameters meet the design drawings, checks for standing water (which must be pumped out before poured concrete placement), and confirms that any required rebar or anchor bolts are properly positioned. This inspection is often the one that reveals problems: holes that are too shallow, holes that hit rock before 36 inches and require an engineer's assessment, or anchor bolt patterns that don't match the approved drawings.

The final inspection covers everything from decking surface to railings, stairs, and handrails. Inspectors check guardrail height (minimum 36 inches above the deck surface), baluster spacing (no opening more than 4 inches, tested with a 4-inch sphere), stair riser height consistency, tread depth, and handrail graspability. They will also verify that the ledger board (on attached decks) has proper flashing installed and that the fastener pattern matches the approved drawings. In Aurora, inspectors are particularly attentive to ledger connections because Front Range freeze-thaw cycles accelerate wood rot at unflashed ledgers, and water intrusion at the ledger-to-wall connection is one of the most common deck structural failures in Colorado. If there are any outstanding HOA-related conditions on the permit, the city may also require documentation that the HOA gave final approval before issuing the certificate of completion.

What a deck costs in Aurora

Aurora's deck construction market reflects the strong demand from the city's 381,000+ residents, many of whom live in single-family homes with backyards well-suited to outdoor living. Pressure-treated wood decks run approximately $35–$55 per square foot for contractor-built projects, putting a typical 300-square-foot deck at $10,500–$16,500 before permit fees. Composite decking (Trex, TimberTech, Fiberon) runs $55–$90 per square foot installed, putting a 300-square-foot composite deck at $16,500–$27,000. Premium hardwoods like Ipe or Cumaru run $80–$120 per square foot installed. These ranges are for the Aurora metro area specifically and reflect both local labor rates and the premium Aurora contractors charge for the footing work required by the 36-inch frost-depth rule—two or three extra feet of excavation per post adds meaningful labor cost compared to warmer-climate builds.

Add to the contractor cost: Aurora city permit fees ($150–$500 depending on project valuation), any HOA application fees (typically $50–$200 in Aurora's master-planned communities), an engineering review if the deck is unusually large or positioned on expansive soils (typically $400–$800), and materials contingency for decks near expansive clay areas where post excavation sometimes hits rock or groundwater. Budgeting $500–$1,200 in permit-and-ancillary fees on a typical Aurora deck project is realistic.

What happens if you skip the permit in Aurora

Aurora's code enforcement staff investigates unpermitted construction complaints and also flags unpermitted work through the permit records database when homeowners apply for unrelated permits or when the city processes building-related business licenses at an address. If Aurora discovers a deck was built without a permit, the city will issue a Stop Work Order if construction is still ongoing, or an Order to Obtain Permit if the work is complete. The investigation fee—often called a double-permit fee—means the permit will cost significantly more after the fact than it would have cost originally. The city may also require portions of the deck to be exposed for inspection to verify footing depth and structural connections that are no longer visible.

The financial exposure extends well beyond the city's investigation fees. Homeowners insurance policies typically exclude coverage for damage that originates in unpermitted structures—meaning if an unpermitted deck collapses and injures a guest, the homeowner's liability coverage may not apply. Title companies increasingly flag unpermitted structures during real estate transactions; buyers' lenders often require that unpermitted work be legalized or demolished before the loan will close. In Aurora's active real estate market, an unpermitted deck discovered during the title search can delay closing by weeks or cause a deal to fall apart entirely.

The after-the-fact permit process in Aurora requires submitting construction drawings that reflect what was actually built, not a proposed design. If the deck does not meet current code at the time of the after-the-fact permit application—even if it met code when it was built, because code changes—the homeowner must bring it into compliance before a certificate of completion can be issued. In the worst cases, this means rebuilding railings, adding footings, or rerouting stair configurations. The total cost of legalizing an unpermitted deck in Aurora typically exceeds $2,000–$8,000 in combined fees, engineering, and remediation work, compared to $250–$500 if the permit had been pulled up front.