Colorado permit requirements
We have read and dated 30 permit rules across 3 jurisdictions in Colorado. They do not all say the same thing: deck thresholds alone run from 12 to 30 inches across 2 of them.
- Jurisdictions
- 3
- Verified rules
- 30
- Permit always required
- 16
- Depends on the project
- 13
Do you need a building permit in Colorado?
Usually yes, but not from Colorado itself: permits are issued by the city or county, not the state, so the rule that governs your project is the one your own jurisdiction publishes. 16 of those local rules require a permit outright, 13 depend on a size or scope condition the office publishes, and 1 needs none. Colorado sets the building code those local rules derive from; your city or county sets the threshold and the fee.
Do Colorado jurisdictions agree?
Every row below is a measurement at least two Colorado jurisdictions publish, compared against each other. This is the question a statewide answer cannot settle, because the number that governs your project is the one your own city or county publishes.
| Project | Published threshold | Jurisdictions | Agreement |
|---|---|---|---|
| Deck | 12 to 30 inches | 2 | 2 different numbers |
| Fence | 4 to 7 feet | 2 | 2 different numbers |
| Shed | 120 to 200 sq ft | 3 | 2 different numbers |
0 of 3 comparable measurements are uniform across Colorado; 3 are not. Latest verification 2026-08-16.
Where Colorado jurisdictions split
The verdict for each project across the 3 Colorado jurisdictions we cover. On 7 of 10 projects they do not give the same answer, which is why a statewide answer is not one.
| Project | Permit required | Depends | No permit | Across the state |
|---|---|---|---|---|
| Deck | 1 | 2 | Answer varies | |
| Electrical | 2 | 1 | Answer varies | |
| Fence | 2 | 1 | Answer varies | |
| HVAC | 2 | 1 | Answer varies | |
| Plumbing | 2 | 1 | Answer varies | |
| Pool | 2 | 1 | Answer varies | |
| Shed | 1 | 2 | Answer varies | |
| Patio | 3 | Same answer everywhere | ||
| Roof Replacement | 3 | Same answer everywhere | ||
| Solar | 3 | Same answer everywhere |
Building without a permit in Colorado
Colorado has no single statewide building code, so building permits are issued and enforced locally: counties adopt building codes under C.R.S. 30-28-201, and once a code is adopted, C.R.S. 30-28-205 makes it unlawful to erect, alter, or remodel a structure without first obtaining a permit. Violating a county building code is a civil infraction under C.R.S. 30-28-209, which carries a fine of up to $100 per offense under C.R.S. 18-1.3-503(1.6), with each day counted as a separate offense, and the county can also ask the county court to impose a civil penalty of $500 to $1,000 under C.R.S. 30-28-210, plus up to $100 for each day the violation continues after the court order; an unpaid penalty becomes a lien on the property collected like unpaid taxes.
Penalties, the as-built path, and what the statute actually says
What you can build without a permit in Colorado
1 of the 30 answered rules across Colorado need no permit at all and 13 turn on a size or scope condition the jurisdiction publishes, by project and jurisdiction, in each office's own words.
What a permit costs in Colorado
There is no single Colorado permit fee. Each jurisdiction in Colorado sets and publishes its own, and they do not use the same pricing model, so the figure that applies to your project is the one your own city or county publishes. Below is every Colorado project where we have quoted one, verbatim, from the office's own schedule.
| Project in Colorado | Jurisdictions publishing a fee |
|---|---|
| Deck | 3 |
| Electrical | 3 |
| HVAC | 3 |
| Plumbing | 3 |
| Roof Replacement | 3 |
| Solar | 3 |
Each row links to the Colorado table carrying every quoted fee, its source and its verification date. We do not publish a Colorado average: the notes mix flat minimums, valuation percentages and per-fixture charges, so an average would be a number no office charges.
Building code in Colorado
No statewide residential building code; home rule, adopted locally. Counties and cities adopt their own codes, typically a version of the International Residential Code (IRC).
Administered by Local county or city building department.
Colorado is largely home rule for building codes. The adopted edition varies by jurisdiction.
Most local permit thresholds derive from this code. See our sources and standards.
What each Colorado jurisdiction publishes
One line per jurisdiction, written from its own rules rather than from a state summary. This is the section that used to be a list of links, and the states with the fewest jurisdictions to compare are the ones it says the most about.
- Aurora 10 rules
2 of 10 projects always need a permit and 8 turn on the size or scope of the work. Only roof replacement and solar work always needs one. Published thresholds include deck at 30 inches and fence at 7 feet.
- Denver 10 rules
6 of 10 projects always need a permit and 4 turn on the size or scope of the work. The ones that depend on the project are deck, fence, patio and shed. Published thresholds include deck at 12 inches and fence at 4 feet.
- Jefferson County 10 rules
9 of 10 projects need a permit, and 1 does not. The ones that depend on the project are patio. No permit at all for fence. Published thresholds include roof replacement at 25 percent and shed at 120 sq ft.