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Information for commercial and multifamily projects only. Guidance for residential projects is in the Home Projects section.

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Denver’s architects and professional engineers evaluate design plans in accordance with Denver's adopted building codes. Make sure to submit engineered drawings, and any documents pertinent to the plans, such as calculations, specifications, and energy code compliance information, if your project includes any of the work described below.

This is not an exhaustive list of items that require a building code review, but is intended to be representative of common questions our reviewers receive.

Other helpful resources: Commercial walk-through counters | Log in counter

Building an addition

Building an addition always requires a building (architectural/structural, electrical, mechanical, plumbing) and SUDP review, and may also need a transportation, health, or other reviews depending on the scope of the addition. Additions also need zoning permits, which will look at maximum lot coverage and parking requirements, among other zoning standards.

Acquiring/expanding into additional space

Acquiring additional square footage, such as expanding into an adjacent space, will need an architectural review to ensure life safety criteria are met for the increase in capacity in accordance with the IEBC, even if no construction is proposed. It will also need a zoning review to ensure parking requirements continue to be met, given the larger space. Any remodel or tenant-finish work accompanying the expansion will require building permits.

For new and replacement cooking appliances, you will need to demonstrate that the kitchen hoods serving those appliances and their make-up air (MUA) units have the capacity to support the new equipment. All appliance changes will need a mechanical review for hood capacity, MUA, and exhaust rates.

An electrical review is needed before installing any new cooking appliances if these appliances will not be plugged directly into an existing receptacle.

A health review is also needed before installing any new cooking appliances or replacing existing equipment.

In addition, all newly installed equipment must comply with efficiency standards in the International Energy Conservation Code (IECC), which will be verified either during plan review or at inspection.

Gas appliances: New or changed gas appliances will also need a plumbing review.

A building code review is required anytime the use of a space changes

All buildings are classified by an occupancy category found in the building code, which dictates not only the structural and life-safety elements needed for that type of building but also items like the number of toilets, sinks, and drinking fountains required. When the occupancy or use of a space changes (e.g., adding a commercial kitchen/bar), the building design must be reevaluated for the new use(s) and could require upgrades to egress, fire safety, electrical, and/or plumbing systems.

All spaces undergoing either a change of occupancy per the building code or a change of use (zoning use permits) will need an architectural and structural review as well as electrical, mechanical, plumbing, health, and SUDP reviews.

All construction work, such as erecting, removing, or relocating walls or stairs, or building raised platforms, must have an architectural/structural review. 

If the work in a commercial or multifamily project will include any of the following, an electrical review is required before a permit will be issued.

  • Installing 10 or more new 20-amp, single-pole circuits (120 volts or 277 volts)
  • New circuits rated above 20 amps
  • New three-phase circuits
  • New circuit rated for a voltage other than 120 V or 277 V

Windows, doors, new entrances/exits, and changes to existing egress will need an architectural/structural review. New or changing entrances/exits will also need electrical and SUDP reviews.

Please note that exit signs and exterior lighting are required at all exits. (See 2015 IBC 1008 and 1013.) An electrical review will verify that these items are included in the design, but full electrical plans do not need to be submitted, provided these items are already shown on any architectural plans submitted. Most projects will then be able to obtain a quick permit to install the necessary signage/lighting.

A health review is required for all food concept changes.

A change to the type of cuisine served could also impact how much and what type of cooking appliances are used, and how much grease is produced. Please reference the sections on this page on Appliances, Grease Interceptors, and Kitchen Hoods for specific guidance.

In a restaurant or commercial kitchen, a change to the type of cuisine served, an increase in seating capacity, or a change in the cooking appliances could all have an impact on grease interceptor sizing.

  • Before installing or replacing a grease interceptor, refer to Public Works’ GI sizing calculator (Requires Microsoft Excel Version 2003 or later) and sample grease interceptor designs (PDF). Grease interceptors will need a plumbing and an SUDP review.

For projects that require a grease interceptor, make sure to connect all fixtures in the kitchen and food prep areas to the grease waste sewer line, which is then directed to the appropriately sized grease interceptor, prior to connecting to the domestic sanitary sewer system for the building. Bar areas, beverage stations, restrooms, and any other area that is not in the kitchen or intended for food prep should NOT be directed to the grease waste sewer line, but rather connected directly to the domestic sewer system for the building. 

A mechanical review is required for any HVAC equipment that is not a like-for-like replacement. Like-for-like replacements (no change in geometry, demand, or material) can be installed under a quick permit

New or replacement HVAC equipment will also need an electrical review to verify that the associated fuses, breakers, wiring ratings, and panel loads meet code.

Even when moving into an existing restaurant or commercial kitchen space, there are limitations on what appliances can be under the kitchen hoods. Hoods must be rated for all new appliances to make sure the exhaust mechanisms can accommodate the equipment being used (e.g., whether grease/smoke is produced versus steam/vapor). Hood exhaust demand ventilation or transfer air instead of 100% dedicated make-up air (MUA) may be required.

Kitchen hoods will need a mechanical, electrical, and health review anytime appliances change, or the hood is replaced. Be sure to review both building code policies linked below, as current building codes have more restrictive requirements on kitchen hoods than before.

  • IMC 507 Kitchen hoods and ventilation


Before replacing lighting, the electrical review aims to confirm that the new lighting and lighting controls meet both electrical and energy codes. 

Some minor electrical work can be installed under a quick permit issued online. This will not need electrical plan review. Learn more about quick permits.

An electrical review is needed if your project includes adding any lighting or infrared heating systems to an outdoor seating area.

Outdoor lighting in parking lots; canopy lighting

In May 2018, Denver City Council approved a bundle of text amendments to the Denver Zoning Code, one of which relates to outdoor lighting in parking lots. This amendment establishes limits on how bright parking lot lighting can be, particularly at car dealerships and gas stations or when the lot is directly adjacent to a low-scale residential zone district.

As a result, any new or modified parking lot light fixtures or canopy lighting will need a zoning permit in addition to the standard electrical permit. For zoning regulations on parking lot and canopy lighting, please reference Section of the Denver Zoning Code (PDF).

Outdoor patios in the public right-of-way

An outdoor patio that extends into the public right-of-way will likely take longer to permit than many commercial projects. All outdoor patios need zoning and building reviews, but if the patio will extend into the right-of-way (streets, alleys, and sidewalks), it will also need encroachment/street occupancy permits and a street furniture permit for the tables, chairs, and railings from Public Works. 

Important building codes to note

  • IBC 903.2.1.2 governs when increasing the indoor seating or covered outdoor seating will require automatic fire sprinklers. Most restaurants, bars, and commercial kitchens are a Group A-2 occupancy. 
  • Outdoor seating for 50 people or more will need two exits from the outdoor seating area. Any doors or gates must swing open in the direction of exit travel. 
  • All dining and drinking areas must be accessible to all guests so people with disabilities have access. Building codes limit any non-accessible elevated seating areas (e.g., a mezzanine) to less than 25% of the total seating area. (See 2015 IBC 1108.2.9)

A plumbing permit is required whenever plumbing fixtures are added, replaced, or relocated, including for toilets, water fountains, sinks (hand sinks, floor sinks, food prep sinks), and water heaters. Any changes to plumbing fixtures in restaurant or commercial kitchen spaces will also require a health review.

Some like-for-like replacements of equipment (no change in geometry, demand, or material) can be installed under a quick permit issued online. These will not need a plumbing plan review. Learn more about quick permits.

Any interior or exterior remodel of any portion of the space will require an architectural review to ensure life safety criteria as outlined in the IEBC are met. This includes a remodel of a kitchen, bar, dining areas, storage areas, basement, entrances or exits, ramps, platforms, equipment, bathrooms, or any accessibility features. Your project will likely need to be issued a new maximum occupant load certificate for posting publicly in your space.

When the remodel includes electrical work, new or upgraded mechanical equipment, or plumbing work, you will also need electrical, mechanical, and plumbing reviews. All remodels need an SUDP, as even small changes could impact a site's sewer use or drainage.

Any remodel to a restaurant or commercial kitchen will receive a health review.

The installation of either solar panels or wind turbines requires an electrical permit, and may also require Landmark Preservation approval, zoning permits, or plumbing permits under certain conditions. 

Visit the online project guide for solar panels for details on what to submit and where to apply, or download building code policy IRC M2301 (PDF).

All wind turbines must be logged in for an electrical and structural plan review. Submit PDFs of your plans/documents -- digitally signed and stamped (PDF guide) -- by email to

All group homes must comply with Denver Building and Fire Code. Depending on the number of occupants and level of care, the group home may need to install or establish the following: 1) a sprinkler system; 2) two independent exits; 3) a facility personal care plan; 4) an evacuation policy; 5) a smoke alarm system; 6) emergency escape and rescue openings; and 7) fire-resistive-rated walls and floors. For reference when examining building code requirements, a group home is classified as both an Institutional Group I-1 occupancy and Residential Groups R-3 and R-4 occupancies per the International Building Code (IBC). 

In addition to building permits, all new or changing residential care facilities will need a zoning permit.

  • Reconfiguring the current layout
  • Changing the furniture in a dining area
  • Adding indoor or outdoor seating

Reconfiguring restaurant furniture may increase the restaurant’s design occupant load. For example, replacing moveable tables and chairs with booth seating may increase the number of people in the dining area. Adding more tables/chairs either inside or outside could increase the design occupant load and trigger necessary upgrades to the number of plumbing fixtures provided (toilets, sinks, water fountains), the number of exit routes provided, or the need to provide automatic fire sprinklers. An architectural review will evaluate these items to determine if the restaurant’s current design can support the proposed changes in seating or layout. Plumbing, health, and SUDP reviews are also needed.

Important building codes to note:

  • All dining and drinking areas must be accessible to all guests so people with disabilities have access. Building codes limit any non-accessible elevated seating areas (e.g., a mezzanine) to less than 25% of the total seating area. (See 2015 IBC 1108.2.9)
  • IBC 903.2.1.2 governs when increasing the indoor seating or covered outdoor seating will require automatic fire sprinklers. Most restaurants, bars, and commercial kitchens are a Group A-2 occupancy. 
  • Outdoor seating for 50 people or more will need two exits from the outdoor seating area. Any doors or gates must swing open in the direction of exit travel. See also "Outdoor patios."

New or replacement walk-in coolers can be included on the plans submitted for a commercial construction permit or permitted independently from other work.

On your drawings, clearly show the dimensions of the walk-in cooler, location of the condenser, and the details of the cooler, including which direction the door swings. Provide the flame and smoke spread indexes for the insulation and make sure to specify what insulation is used. Walk-in coolers must meet all energy code requirements outlined in IECC C403.2.16

Alternatively, the mechanical and energy efficiency details for the walk-in cooler can be submitted and permitted at the commercial mechanical/plumbing walk-through counter while construction is ongoing. See “deferred submittals” under Step 5 on the Restaurants page for more detail.

  • Who can install the walk-in cooler? A refrigeration contractor must install the cooler’s refrigeration, and can also install the walk-in box if it is small enough to meet the criteria in building code policy ADMIN 120B.

A strictly like-for-like water heater replacement, with no other work involved, can be permitted as a quick permit without plan review.

Most other new or replacement water heaters can be permitted at the electrical and plumbing walk-through counters, if the power to the water heater is rated for a maximum of 20 amps, and at 120 volts or 277 volts only (a single-pole circuit). 

However, if the water heater circuit is rated for 30 amps or more; requires a 2- or 3-pole circuit; or the water heater is part of a larger project at a restaurant, marijuana facility, or other H or I building occupancy, then it must be logged in for review.