The city is in the process of updating its Energy Conservation Code. Learn more about the process and proposed updates.

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What is the Energy Conservation Code?

The City of Boulder Energy Conservation Code sets minimum energy performance standards for newly constructed and renovated buildings.

The code is updated on a three-year cycle, the latest revision was approved by City Council on June 6, 2024. The new code will go into effect on Dec. 1, 2024. The city’s current code is a more rigorous, local version of the 2018 International Energy Conservation Code. With every code update, the city aims to set a path toward net-zero emissions for all building operations, an important milestone in meeting Boulder’s broader citywide target of net-zero emissions by 2035.

Why do energy codes matter?

Energy codes require new buildings to be more efficient and connected to our increasingly renewable grid, thereby helping to:

  • Reduce climate warming greenhouse gas emissions.
  • Save energy.
  • Protect people from rising utility costs.

They also support making indoor spaces healthier and more comfortable. People spend as much as 90% of their time inside, where they are exposed to unhealthy fumes from gas equipment. Energy codes make the transition to healthier electric alternatives a standard in new buildings, helping occupants breathe easier and join our effort to address climate change.

The Code’s Goals and Objectives

The overall, long-term goal is to build high performing residential and commercial buildings that efficiently and effectively serve the needs of their occupants without contributing to the climate crisis. The objectives below are designed to support this overarching goal.

Supporting the City’s Climate Commitment

  • Achieve and sustain 70% greenhouse gas (GHG) reduction by 2030.
  • Design and adopt codes that lead to net-zero emissions for all building operations, helping meet Boulder’s broader citywide target of net-zero emissions by 2035.
  • Support technologies and practices that move the community toward local and distributed energy systems that support 100% renewable energy, economic vitality and community resilience.

Promoting High Performance Buildings

  • Promote sustainable building practices throughout the lifecycle of a building – from initial construction and use to dismantling its parts for reuse and recycling.
  • Encourage the development and ongoing maintenance of safe, comfortable and efficient buildings.
  • Support resilience and reduce the impacts of rising energy costs.

Creating Effective and Viable Codes

  • Adopt codes that are practical, enforceable and regularly updated.
  • Provide building owners and design professionals straightforward, affordable paths to comply with energy codes.

A Closer Look at the Approved Code Changes

The most significant changes include:

All Electric Requirements for New Construction and Major Renovations

This update will require that most equipment and appliances installed as part of a new construction project or major renovation be electric. Natural gas appliances will still be permitted in some applications, such as commercial kitchens, scientific facilities and certain industrial buildings.

Electric Vehicle Infrastructure Requirements

This update adjusts existing requirements to align with new state mandates, and better supports electric vehicle adoption rates.

Residential Energy Performance

In addition to the all-electric appliance requirements, the energy code update will:

  • Provide additional pathways for code compliance.
  • Clarify and simplify the Energy Rating Index by setting a pre-solar minimum performance requirement.
  • Eliminate the need for builders and homeowners to find off-site solutions if available roof space is insufficient for the amount of solar necessary to meet post-solar performance requirements.
  • Maintain requirements that make buildings ready for solar technology as outlined in the 2020 code.
  • Create more opportunities for conservation through additional credits towards compliance.
  • Clarify and simplify code compliance for renovations, additions, alterations and repairs for existing buildings.
  • Achieve greater alignment regionally with other municipalities as well as the international code.

Commercial Energy Performance

In 2020, the city introduced the Energy Use Intensity (EUI) performance pathway. The EUI is the measurement of the total energy use per square foot of building space. The code update will add Fixed EUI Performance targets for large commercial, retail, and restaurants in addition to the current building types permitted. Reference standards will also be updated to the newest versions.

Envelope Backstop

With the cost of renewable energy decreasing, some projects simply install large solar arrays to achieve building performance requirements instead of investing in efficiency upgrades. The updated code will maintain envelope efficiency standards outlined in the 2020 code to ensure all elements of a newly constructed commercial building’s envelope – its windows, walls, floor slabs, roof assemblies and doors – remain efficient and are not traded-off for other efficiencies in the building.

Renewable Offsets

Commercial projects that use fossil fuels will be required to offset 100% of those fuels through on-site renewable energy generation.

Embodied Carbon

Every part of a building creates greenhouse gas emissions through the production and transport of materials used to construct them. We call these emissions embodied carbon.

Preserving structures and reusing and recycling building materials prevent us from generating more carbon because we are using what already exists instead of creating something new. While the energy code specifies how energy gets used in buildings, it is just one of many codes that govern building construction. The city expects to begin an update to the rest of these codes in 2024, and reducing embodied carbon will likely be a key part of that effort.

Specific parameters that will change:

Building Type 2020 CoBECC 2024 CoBECC Comments
Residential 1 dedicated 40A, 208/240V circuit No Change
Multi-Family (includes hotels) with 10 or less parking spaces 1 space pre-wired 100% of spaces pre-wired
Multi-Family (includes hotels) with greater than 10 parking spaces 5% of spaces with charging equipment installed 10% of spaces pre-wired 40% of spaces with conduit installed and service capacity available for future use 5% of spaces with charging equipment installed 15% of spaces pre-wired 40% of spaces with conduit installed and service capacity available for future use40% of spaces with conduit installed
Commercial Buildings with 10 or less parking spaces 1 space pre-wired 2 spaces pre-wired Also lowers definition of small lot from 25 spaces to 10 spaces
Commercial Buildings with greater than 10 parking spaces 5% of spaces with charging equipment installed 10% of spaces pre-wired 10% of spaces with conduit installed and service capacity available for future use 5% of spaces with charging equipment installed 10% of spaces pre-wired 10% of spaces with conduit installed and service capacity available for future use 20% of spaces with conduit installed
Parking Garages N/A 100% of spaces must at least have conduit installed See Multi-Family or Commercial Buildings above for additional requirements

Frequently Asked Questions

Read our answers to frequently asked questions about the proposed energy code updates.

As part of the code update, staff and city consultants are analyzing the financial impacts of different proposed requirements. While some elements of the proposed code have increased costs associated with them, other elements are expected to reduce costs. As with past code updates, staff’s recommendations to City Council will strive to ensure that savings from efficiency requirements offset any increases in initial construction costs.

Many Colorado communities have adopted the 2021 International Energy Conservation Code (IECC), which is the current national code. Boulder’s 2024 energy code is comparable and, in some cases, more stringent than the 2021 IECC. The update will align Boulder with communities that have both adopted the 2021 IECC and have set all-electric requirements for new construction.

The new code will take effect December 1, 2024.

No, the proposed update would not ban the use of natural gas, nor would it require that people currently using gas equipment switch to electric alternatives. The code update requires that certain types of appliances be electric for new construction. These restrictions only apply to equipment that has efficient, cost-effective and available alternatives. There are also exemptions for the electric-only requirement, including commercial cooking equipment, hospitals, laboratories and certain types of industrial spaces.

Yes, there are a wide variety of heat pumps rated to work in cold climates, like Boulder.

While Net Zero Energy (NZE) can be defined several ways, in this context, it means:

The amount of renewable energy produced on site, plus the amount purchased from approved community energy systems, is equal to or greater than the annual energy use of the site.

This definition makes it possible for all buildings to become NZE even with poor solar access or other site constraints. Current conversations among experts and advocates at the national level have introduced alternative terminology, including terms such as “net zero carbon” and “net zero emissions.” City staff are engaged in these conversations and may propose updated terminology in future code updates.

The next step past NZE is net-zero carbon. There are two types of carbon emissions: operational carbon and embodied carbon. Energy codes address operational carbon by requiring efficiency upgrades that reduce emissions. Embodied carbon accounts for all the emissions created through the process of constructing a building and creating its parts. This includes the emissions created by extracting, processing and transporting building materials, like concrete and steel.

While the energy code focuses on operational emissions, some key components such as waste reduction, water efficiency and transportation are covered in applicable sections of the International Building Code, International Residential Code or other international codes.