Almost every deck we build needs a permit. The rule of thumb across the south metro: if it's attached to the house, more than 30" above grade, or over ~200 sq ft, you're pulling one. Here's what that actually involves.
What the permit process looks like
1Site plan. Your lot with the deck drawn in — setbacks from property lines matter most (usually 5–15 ft rear, varies by zone and HOA).
2Framing plan.Footings, posts, beams, joists, ledger attachment, railing height. Front Range frost depth means footings go 30–36" down.
3Submit & wait. Most south-metro cities turn residential deck permits around in 1–3 weeks. Fees typically run $150–500.
4Inspections. Usually three: footing holes (before concrete), rough framing, and final. Miss one and you may be digging things back up.
Code numbers that trip people up
Guardrail required above grade30"
Minimum residential guardrail height36"
Max gap in railing (the "4-inch sphere" rule)< 4"
Stair rise / run limits7¾" / 10"
Footing depth (frost line, Front Range)30–36"
Where to file, by city
Centennial · Greenwood Village · Cherry Hills Village · Lone Tree · Castle Rock file with their own building departments. Highlands Ranch files through Douglas County. Unincorporated Arapahoe County addresses file with the county. Every one of them also wants HOA sign-off first if you have one — check that before drawing anything.
Codes change and cities amend them. Treat this as orientation, and confirm specifics with your building department — or have us pull the permit; it's included in every Haka build.