Colorado Commercial Fire & Life Safety: Navigating Local IBC & IFC Amendments

Colorado operates as a "home rule" state, meaning there is no single, statewide mandatory building code. Instead, each municipality and county adopts and amends its own set of construction codes. While most major jurisdictions base their codes on the International Code Council (I-Codes), local amendments can significantly alter design requirements for fire protection, life safety, egress, and accessibility.

For architects, engineers, and contractors, this means a project in Denver may face different rules than an identical one in Aurora or Fort Collins. Key takeaways for designing compliant commercial buildings in Colorado include:

• Local Adoption is Key: Always verify the specific code editions (e.g., 2021 IBC, 2021 IFC) and local amendment packages with the Authority Having Jurisdiction (AHJ) before beginning design.

• Denver's Unique Code: The City and County of Denver publishes the Denver Building and Fire Code (DBFC), a comprehensive set of amendments to the I-Codes that includes stricter energy provisions, specific guardrail height requirements, and unique accessibility rules.

• Fire Marshal Authority: Local fire marshals (like Aurora Fire Rescue) often publish their own design criteria for fire apparatus access, water supply, and fire alarm systems that may be more restrictive than the base International Fire Code (IFC).

• Zoning Overrides Building Code: Allowable height, area, and building envelope are governed by both the building code (IBC Chapters 5 & 6) and local zoning or land use codes. The most restrictive of the two will always govern the design.

Why This Matters for Your Project

Understanding this regulatory landscape is critical for avoiding costly redesigns and permitting delays. A design that is perfectly compliant with the base IBC may be rejected during plan review due to a local amendment. Early in the design process, project teams must:

1. Identify the AHJ: Determine the city, county, or special district with permitting authority.

2. Obtain Local Codes: Acquire the currently adopted code editions and all local amendment documents.

3. Consult the Fire Marshal: For projects of significant size or complexity, a pre-design meeting with the local fire department or fire protection district is essential to clarify requirements for site access, fire flow, and fire protection systems.

Failing to account for local nuances—from Denver's 42-inch guardrail rule on R-2 rooftops to Aurora's fire apparatus turning radii—can jeopardize project timelines and budgets.

What are the specific model codes (IBC, IRC, IECC, etc.), editions, and significant local amendments currently adopted by the City and County of Denver, and how do they impact the design of a new high-rise, mixed-occupancy (R-2 over A-2) building?

The City and County of Denver has adopted the 2021 International Codes as the basis for its regulations, but modifies them extensively through the 2022 Denver Building and Fire Code (DBFC). For a new high-rise, mixed-occupancy building, this comprehensive set of local amendments creates a unique regulatory environment that goes beyond the standard I-Codes.

The primary codes and standards governing such a project in Denver are:

• 2022 Denver Building Code: Amends the 2021 International Building Code (IBC).

• 2022 Denver Fire Code: Amends the 2021 International Fire Code (IFC).

• 2022 Denver Energy Code: Amends the 2021 International Energy Conservation Code (IECC) with significantly stricter requirements.

• Other Adopted Codes: Including the 2021 IMC (Mechanical), 2021 IPC (Plumbing), and 2023 NEC (Electrical).

Impact on a High-Rise, Mixed-Occupancy (R-2 over A-2) Building:

A building with an occupied floor more than 75 feet above the lowest level of fire department vehicle access is classified as a high-rise (IBC §202, §403). This triggers a host of stringent requirements, which are further refined by Denver's amendments.

1. High-Rise Specific Requirements (IBC Chapter 4 & DBFC):

   • Automatic Sprinkler System: A supervised automatic sprinkler system (NFPA 13) is mandatory throughout the entire building (IBC §403.2.1).

   • Fire Alarm & Communication: An emergency voice/alarm communication system is required (IBC §403.4.4).

   • Fire Command Center: A dedicated Fire Command Center meeting the specific layout and equipment requirements of IBC §403.6 is mandatory.

   • Smokeproof Enclosures: Stairways serving the high-rise portion of the building must be designed as smokeproof enclosures per IBC §909 or §1023.11 (IBC §403.5.4).

   • Standby and Emergency Power: The building must have standby and emergency power systems to operate critical life safety equipment, including egress lighting, fire pumps, and elevators (IBC §403.4.8).

2. Mixed-Occupancy Separation (IBC Chapter 5):

   • The project involves a Group A-2 (Assembly, e.g., restaurant/bar) and a Group R-2 (Residential) occupancy.

   • Per IBC Table 508.4, the occupancies must be separated by a 2-hour fire barrier when the A-2 is located below the R-2. This separation must be continuous and extend from the top of the floor/ceiling assembly to the underside of the floor or roof sheathing above.

3. Significant Denver Amendments (DBFC):

   • Denver Energy Code: Denver's energy code is one of the most progressive in the country. It will heavily influence the building envelope design (insulation, glazing performance), HVAC systems, and lighting controls, often requiring performance modeling to demonstrate compliance.

   • Green Buildings Ordinance: Denver has requirements for cool roofs and may require portions of the roof to be "green roof ready" or equipped with solar panels, impacting structural design and roof assembly details.

   • Egress and Accessibility: The DBFC contains specific amendments to IBC Chapter 10 (Means of Egress) and Chapter 11 (Accessibility) that must be reviewed. For example, Denver has modified requirements for areas of refuge and accessible means of egress.

Designing a high-rise in Denver requires a thorough review of not just the base IBC and IFC, but a line-by-line analysis of the DBFC amendments, which often add layers of complexity and stringency.

What are the allowable height and area limitations for a Type III-A, Group R-1 hotel in Fort Collins, considering both sprinkler increases (NFPA 13) and open frontage calculations under the locally adopted IBC? How do the Fort Collins land use code requirements further restrict the building envelope beyond the building code?

The allowable height and area for a Type III-A, Group R-1 hotel in Fort Collins are determined by the 2021 International Building Code (IBC), but are ultimately limited by the more restrictive requirements of the Fort Collins Land Use Code. You must calculate the maximums allowed by both and adhere to the smaller envelope.

1. Calculation under the 2021 IBC:

First, we establish the base limitations and then apply the permitted increases.

• Base Allowable Limits (IBC Tables 504.3 & 506.2):

  • Construction Type: III-A (Combustible construction with noncombustible exterior walls and fire-retardant-treated wood framing).

  • Occupancy Group: R-1 (Residential - transient, like hotels).

  • Base Allowable Height: 4 stories and 65 feet.

  • Base Allowable Area per Floor: 14,000 square feet.

• Sprinkler Increase (IBC §504.2 & §506.3):

  • Because the building will be equipped with an NFPA 13 automatic sprinkler system, significant increases are permitted.

  • Height Increase: Add 1 story and 20 feet. The new limit is 5 stories and 85 feet.

  • Area Increase Multiplier (Is): For a multi-story building, the base area can be multiplied by 3.

    • 14,000 sq. ft. * 3 = 42,000 sq. ft. per floor.

• Open Frontage Increase (IBC §506.2):

  • This increase is permitted when the building has open space or public ways on its perimeter. The increase is calculated with the formula: If = [F/P - 0.25] * W/30.

  • F = Building perimeter fronting a public way or open space ≥ 20 feet wide.

  • P = Total building perimeter.

  • W = Weighted average width of the open space.

  • Example Calculation: Assume a 150' x 200' building (P=700 ft) with 500 ft of its perimeter (F) facing a 30-foot-wide street (W=30).

    • If = [500/700 - 0.25] * 30/30 = [0.714 - 0.25] * 1 = 0.464

    • This allows a 46.4% increase to the base area.

• Total Allowable Area (IBC §506.1):

  • The total allowable area per floor is the base area plus the sum of the frontage and sprinkler increases.

  • Allowable Area = Base Area + (Base Area * If) + (Base Area * Is)

  • However, the code simplifies this: The tabular area is first increased by the frontage increase, and that sum is then multiplied by the sprinkler increase factor. Let's use the formula from IBC §506.1: A_t = A_a * (I_s + I_f) where At is the new total allowable area per story. No, that's not quite right.

  • Correct calculation per IBC §506.1: A_t = A_a + A_a*I_s + A_a*I_f.

  • Let's re-calculate: Total Allowable Area = 14,000 * (1 + 3 + 0.464) = 14,000 * 4.464 = 62,496 sq. ft.. Correction, the formula is Total Allowable Area per story = Tabular area * (Frontage increase factor + Sprinkler increase factor). Wait, that's not it either. The proper application is that the allowable area per story is the tabular area (Aa) plus the area increases for frontage (Aa x If) and sprinklers (Aa x Is). So, At = Aa + (AaIf) + (AaIs). Correction again, let me check the 2021 IBC §506.1. It states The maximum area of a single-story or multistory building shall be the aggregate of the floor areas of all stories...and shall not exceed the tabular allowable area per story (Aa), as modified by Section 506.2 and 506.3. Section 506.4, Total allowable floor area, states The maximum total allowable floor area...shall be determined by multiplying the allowable area per story (As), as determined in Section 506.2, by the number of stories...

  • Let's reset. Allowable area per story (A'a) = Aa * (Is + If). This isn't right.

  • The correct approach from the IBC Commentary: The total allowable area for a multi-story building is (Allowable Area per story) x (Number of stories). The allowable area per story (As) is Aa + (Aa*If). The number of stories increase from the sprinkler system is already factored into the height. The area increase for sprinklers (multiplying by 3) applies to the base tabular area.

  • Let's try again with clarity:

    1. Allowable area per story (A_s): A_s = A_a + (A_a × I_f) where A_a is the tabular area from Table 506.2.

    2. Total Allowable Building Area (A_total): A_total = A_s × Number of stories allowed.

    3. Sprinkler Modification: The sprinkler system allows the total area to be 300% of the calculated floor area for a multistory building. A_total_sprinklered = A_total * 3.

  • So, using the example:

    • A_s = 14,000 + (14,000 * 0.464) = 14,000 + 6,496 = 20,496 sq. ft. per story.

    • A_total for 5 stories = 20,496 * 5 = 102,480 sq. ft.

    • The IBC allows this. This is the maximum building envelope from a fire safety perspective.

2. Restrictions from the Fort Collins Land Use Code:

This is the critical step. The Fort Collins Land Use Code will impose restrictions that are often more stringent than the IBC maximums. These typically include:

• Zoning District Height Limits: The specific zoning district of the property will have a maximum building height that may be significantly less than the 85 feet calculated under the IBC. For example, a zone may limit height to 55 feet.

• Setbacks: Required front, side, and rear yard setbacks will constrain the building's footprint, directly reducing the achievable area per floor.

• Floor Area Ratio (FAR): The Land Use Code often specifies a maximum FAR, which is the ratio of the total building floor area to the area of the lot. For instance, if a 20,000 sq. ft. lot has a FAR limit of 2.0, the total building area cannot exceed 40,000 sq. ft., regardless of what the IBC allows.

• Building Step-Backs/Massing: Some zones require upper floors to be stepped back from the property line to reduce visual impact, further limiting the area of upper stories.

Conclusion: The design team must first calculate the maximum theoretical envelope under the IBC (5 stories, 85 feet, and potentially a large floor plate). Then, they must overlay the constraints from the Fort Collins Land Use Code. The final, buildable envelope is the one that complies with both sets of regulations. In almost all urban and suburban contexts, the Land Use Code will be the limiting factor for height and overall massing.

My project is a large industrial facility (Group F-1) in Aurora. What are the specific fire code requirements enforced by the Aurora Fire Marshal for fire apparatus access roads, fire flow, standpipe systems, and fire alarm system type, and do these differ from the base IFC adopted by the state?

For a large Group F-1 industrial facility in Aurora, you must comply with the City of Aurora's adopted 2021 International Fire Code (IFC) and, crucially, the Aurora Fire Rescue (AFR) Development, Building & Site Design Criteria. These local criteria often exceed the minimums of the base IFC and are strictly enforced by the Aurora Fire Marshal during plan review and inspection.

Here are the specific requirements and how they typically differ from the base IFC:

1. Fire Apparatus Access Roads:

• Base IFC Requirement (§503): Requires fire lanes to have an unobstructed width of not less than 20 feet and support the imposed load of fire apparatus.

• Aurora Fire Rescue Requirement: AFR's criteria are more detailed and stringent. They typically require:

  • Width: A minimum unobstructed width of 26 feet for primary access roads.

  • Turning Radii: A minimum inside turning radius of 30 feet and an outside turning radius of 50 feet to accommodate ladder trucks. This is more specific than the general language in IFC Appendix D.

  • Surface: Must be an "all-weather" driving surface, often defined as asphalt or concrete, capable of supporting 75,000 pounds.

  • Dead-Ends: Dead-end fire access roads exceeding 150 feet must have an approved turnaround, with specific dimensions provided by AFR (e.g., a 120-foot hammerhead or 96-foot diameter cul-de-sac).

  • Signage: "No Parking - Fire Lane" signs are required, with specific designs and spacing detailed by AFR.

2. Fire Flow (Water Supply):

• Base IFC Requirement (Appendix B): IFC Table B105.1 provides minimum required fire flow based on construction type and area. For a large, non-sprinklered Type II-B F-1 facility of 30,000 sq. ft., the base requirement might be 2,500 gallons per minute (GPM).

• Aurora Fire Rescue Requirement: AFR uses the IFC tables as a starting point but coordinates closely with Aurora Water to determine the actual available fire flow in the proposed location. They will require:

  • Fire Flow Calculation: A formal fire flow calculation stamped by a Colorado P.E. is required as part of the submittal.

  • Hydrant Location & Spacing: AFR specifies maximum hydrant spacing (e.g., no more than 400 feet apart in commercial areas) and requires hydrants to be a certain distance from the building (e.g., not less than 40 feet). The location of fire department connections (FDCs) relative to hydrants is also scrutinized.

  • On-Site Water Storage/Fire Pumps: If the municipal water supply is inadequate, AFR will require the project to include on-site water storage tanks and fire pumps to meet the required GPM.

3. Standpipe Systems:

• Base IFC Requirement (§905): A Class I standpipe system is required in buildings where any portion of the building's floor is located more than 30 feet above or below the lowest level of fire department vehicle access. For large F-1 facilities, they are also required if the building exceeds certain area thresholds or is designated a high-piled combustible storage facility per IFC Chapter 32.

• Aurora Fire Rescue Requirement: AFR strictly enforces these requirements. The Fire Marshal will pay close attention to:

  • Hose Connection Locations: Ensuring hose connections are located at intermediate landings in exit stairs and as required by IFC §905.4.

  • Pressure: They will verify that the system design provides the minimum residual pressure (100 psi) at the topmost hose connection, which may necessitate a fire pump.

  • FDC Location: AFR has specific preferences for the location of the Fire Department Connection (FDC) to ensure it is visible and accessible for responding apparatus.

4. Fire Alarm System Type:

• Base IFC Requirement (§907): For a Group F-1 occupancy, a manual fire alarm system is required if the occupant load is 500 or more, or if the occupant load is more than 100 persons above or below the lowest level of exit discharge (IFC §907.2.4). An automatic smoke detection system may be required based on specific contents or processes.

• Aurora Fire Rescue Requirement: The Fire Marshal has final say and may require a more robust system. For a large industrial facility, AFR will likely require:

  • Automatic Detection: An automatic smoke or heat detection system, especially if hazardous materials are present or if there is high-piled storage.

  • Notification: They will specify the type of notification appliances (e.g., horn/strobes) and their placement to overcome ambient noise levels common in industrial settings.

  • Monitoring: The system must be monitored by a UL-listed central station service per NFPA 72.

In summary, while Aurora adopts the 2021 IFC, the Aurora Fire Marshal's specific design criteria and enforcement policies function as a critical layer of additional code. Early engagement with AFR is essential for any industrial project.

Under the Denver Building Code amendments, what is the required height for guardrails on rooftop decks accessible to occupants in an R-2 building, and are there different requirements for private vs. common amenity spaces?

Under the 2022 Denver Building Code (DBFC), the required height for guardrails on rooftop decks and other walking surfaces in an R-2 occupancy is 42 inches minimum, regardless of whether the space is a private balcony or a common amenity deck.

This is a direct amendment to the model code. Here's the breakdown:

• Base IBC Requirement (2021 IBC §1015.2): The model IBC requires guards to be a minimum of 42 inches high along open-sided walking surfaces, including mezzanines, equipment platforms, and aisles, that are more than 30 inches above the floor or grade below. It provides an exception allowing a 36-inch guard height for R-2 and R-3 occupancies in certain locations like balconies.

• Denver Amendment (DBFC §1015.2): Denver has removed this exception for R-2 occupancies. The amended text in the DBFC specifically mandates a uniform 42-inch height for guards serving Group R-2 occupancies.

Key Points:

• No Distinction Between Private vs. Common: The Denver amendment does not differentiate between a private rooftop deck serving a single dwelling unit and a common amenity space accessible to all residents. In both cases, if the walking surface is more than 30 inches above the surface below, a 42-inch guardrail is required.

• Reasoning: This local amendment is intended to provide a higher level of safety and consistency in multi-family residential buildings, which are treated as commercial structures under the building code. The city has determined that the risks associated with falls from elevated surfaces warrant the commercial-standard 42-inch height across all accessible areas of an R-2 building.

• Opening Limitations (DBFC §1015.3): The requirement that open guards do not allow the passage of a 4-inch diameter sphere still applies.

For any architect or designer working on a multi-family project in Denver, it is critical to specify 42-inch guardrails for all balconies, terraces, and rooftop decks to comply with the DBFC. Relying on the base IBC's R-2 exception for 36-inch guards will result in a plan review correction.

In a fire-rated corridor in a commercial building, does the Colorado building code allow the use of hold-open devices on fire doors, and if so, must they be tied to the building's fire alarm system?

Yes, building codes throughout Colorado allow the use of hold-open devices on fire doors in rated corridors, but only if they are automatic-closing devices that release upon activation of the fire alarm and smoke detection systems. Standard, un-regulated mechanical or friction-based hold-opens are strictly prohibited.

This requirement is consistent across jurisdictions in Colorado because it is a fundamental life safety principle adopted from the model codes.

• Governing Code Sections:

  • International Building Code (IBC) §716.2.6.1: This is the primary section. It states that automatic-closing fire doors are permitted to be equipped with hold-open devices provided the device is listed and releases upon activation of smoke detectors.

  • NFPA 80, Standard for Fire Doors and Other Opening Protectives: This standard is referenced by the IBC and provides the detailed installation requirements for fire door assemblies, including closing devices.

  • NFPA 101, Life Safety Code: Contains similar language reinforcing the need for automatic release.

How the System Must Function:

For a hold-open device to be code-compliant on a fire door in a required rated corridor (e.g., an egress corridor), it must:

1. Be Electronically Controlled: The device is typically a magnetic holder mounted on the wall or floor that holds the door's armature plate.

2. Release upon Smoke Detection: The device must automatically release and allow the door to close and latch upon activation of smoke detectors. The detectors can be:

   • A listed smoke detector installed within 5 feet of the door on either side.

   • The building's area-wide smoke detection system (if the area is fully covered).

3. Release upon Alarm Activation: The device must also be tied to the building's fire alarm system and release upon a general alarm activation.

4. Release upon Power Failure: The hold-open device must be fail-safe, meaning it will release and allow the door to close if it loses power.

This ensures the fire door can fulfill its purpose: to compartmentalize the building and protect the means of egress from smoke and fire. A simple fusible link is not permitted in this application because it only reacts to high heat, which would be too late to stop the spread of deadly smoke through a corridor.

Additional Supporting Sections

Jurisdictional Variations: The "Home Rule" Challenge in Colorado

Colorado's "home rule" status is the single most important concept for design professionals to grasp. Unlike states with a uniform, statewide code, Colorado delegates code adoption and enforcement to local jurisdictions.

• What this means: A project in unincorporated Jefferson County may be under a different code edition than a project just across the city line in Lakewood. Mountain communities like those in Summit or Eagle County will have significant amendments related to snow loads, ice damming, and Wildland-Urban Interface (WUI) fires that are not found in Front Range communities.

• Best Practice: The first step of ANY project is to contact the local building department to confirm the following:

  • Adopted editions of all I-Codes (Building, Fire, Mechanical, Plumbing, Energy).

  • Adopted edition of the National Electrical Code (NEC).

  • The existence and availability of a local amendment document or municipal code chapter.

  • Specific design criteria published by the local fire, water, or public works departments.

• Major Metro Area Code Snapshot (Always Verify):

  • Denver: 2021 I-Codes with 2022 DBFC amendments.

  • Colorado Springs: 2017 Pikes Peak Regional Building Code (based on 2015 I-Codes).

  • Aurora: 2021 I-Codes with local amendments.

  • Fort Collins: 2021 I-Codes.

  • Boulder: 2021 I-Codes with very stringent local energy code amendments.

Coordination with the Fire Marshal: A Critical Step for Success

For commercial projects, the local Fire Marshal or Fire Chief is an Authority Having Jurisdiction (AHJ) with equal standing to the Building Official. Their review and approval are mandatory. Successful projects integrate their requirements early.

Key Coordination Points:

1. Site Plan Review: The fire department's primary concern with the site plan is apparatus access. They will scrutinize road widths, turning radii, aerial apparatus positioning, fire lane markings, and hydrant locations. Gaining their conceptual approval on the site layout before advancing in design is crucial.

2. Fire Protection Systems: All fire sprinkler, fire alarm, and special suppression system designs require a separate permit, usually from the fire department. These plans must be prepared by qualified individuals (e.g., NICET-certified designers) and are reviewed directly by the fire marshal's office.

3. Fire Department Connection (FDC): The location of the FDC is a frequent point of contention. The fire marshal will want it in a safe, visible, and easily accessible location for the first responding engine company. This must be coordinated with landscaping and site features.

4. Pre-Design Meetings: For complex projects (high-rises, large assembly spaces, industrial facilities), a pre-design or pre-submittal meeting with the building and fire departments is highly recommended to identify major code issues and expectations before hundreds of hours are spent on design.

Common Mistakes & Misinterpretations in Colorado

• Assuming IBC is Enough: The most common mistake is designing to the base I-Codes without obtaining and reading the local amendments.

• Ignoring Snow Load Differences: Designing a roof for a Denver snow load (typically 30 psf) will fail catastrophically in a mountain town like Breckenridge, where ground snow loads can exceed 200 psf. Snow load requirements are highly localized and must be verified.

• Misunderstanding Energy Codes: Major jurisdictions like Denver and Boulder have energy codes that are significantly more demanding than the base IECC. These requirements affect everything from window specifications to mechanical system efficiency and require specialized analysis.

• Forgetting Accessibility Amendments: While IBC Chapter 11 and ANSI A117.1 are the standards, some cities (especially Denver) have their own amendments regarding the number and distribution of accessible parking spaces or dwelling units.

Frequently Asked Questions (FAQ)

1. Does Colorado have a statewide building code? No. Colorado is a "home rule" state where building codes are adopted and enforced at the local city or county level. There is no statewide code that applies to all commercial construction.

2. What is the most common building code edition used in Colorado? As of late 2023/early 2024, the most commonly adopted model codes among the major Front Range jurisdictions are the 2021 I-Codes (IBC, IFC, IMC, etc.). However, some jurisdictions may be on older or newer cycles, so verification is essential.

3. How do I find the specific code for a project in a small town or rural county? You must contact the city or county building department directly. Their contact information is usually available on the official municipal or county website.

4. Are fire sprinklers required in all new commercial buildings in Colorado? Not all, but most. The requirement is based on occupancy group, fire area, and occupant load per IBC Chapter 9. Due to local fire code amendments, the thresholds for requiring sprinklers are often lower (i.e., they are required for smaller buildings) than in the base IBC.

5. What are the basic accessibility requirements in Colorado? Accessibility is governed by Chapter 11 of the locally adopted IBC, which references the ANSI A117.1 standard. Some cities, like Denver, have local amendments that may add to or clarify these requirements.

6. Do I need a special permit for a project in a Wildland-Urban Interface (WUI) zone? Yes. Most mountain counties and foothill communities have adopted a WUI code. This requires specific construction materials and methods, such as ignition-resistant siding, Class A roof coverings, and defensible space around the structure.

7. Are the electrical and plumbing codes also locally adopted? Yes. Local jurisdictions adopt a specific edition of the National Electrical Code (NEC) and a model plumbing code (either the International Plumbing Code or the Uniform Plumbing Code), often with local amendments.

8. How do I handle a conflict between the building code and the fire code? Per IBC §102.1, where there is a conflict between a general requirement and a specific requirement, the specific requirement applies. Where codes conflict, the most restrictive requirement generally governs. Always consult the local building and fire officials for an official interpretation.

9. What are common special inspection requirements in Colorado? They are outlined in IBC Chapter 17 and are consistent with national standards. Common special inspections include high-strength concrete, structural welding, high-strength bolting, post-tensioned slabs, and fire-resistant construction. Requirements can be more stringent in areas with high seismic design categories or unique soil conditions.

10. Is an architect or engineer required for all commercial projects in Colorado? State law, administered by the Colorado Department of Regulatory Agencies (DORA), requires that a licensed architect or engineer prepare and stamp plans for most commercial projects to ensure public health, safety, and welfare. There are very limited exemptions for small, simple structures.