If you follow Emerald on social media, then you know that Matt recently attended the 2023 ASHRAE convention in Florida, where he gave voice to new standards that will help decarbonize our building stock. While he was inspecting the palm trees, Sophia was taking notes from online sessions about changes that will impact how we do energy modeling and GHG emissions assessments. All week long, our chats were blowing up with notes from them both about changes coming to ASHRAE standards — including the stark reality that our climate has already changed. All of this matters to you because states refer to ASHRAE when setting building codes.  


ASHRAE standards have been incorporated into the building codes of 48 states (minus CA and IN) as a minimum requirement for the energy-efficient design and construction of new buildings and their systems. This focus on energy efficiency ensures a healthier building stock and can also translate into significant financial savings for building owners and developers. 


One of the reasons why the ASHRAE standard has been so widely adopted is because it incorporates regional differences in its recommendations. This stems from the fact that energy efficiency is intimately linked with climate. For instance, a building in Alaska will have entirely different insulation needs than one in Florida. 


ASHRAE relies on climate information from the U.S. Department of Energy, which utilizes the International Energy Conservation Code's (IECC) climate zones to help standardize these regional requirements. The IECC climate zones categorize climate regions and provide efficiency standards for each type of climate.  


Now is a critical time for developers — the IECC updates its climate zones every four years, with the next update in 2024. As the climate zones change, we will see a knock-on effect in ASHRAE, local building codes, and sustainability certifications that will noticeably impact developers. 


What Are Climate Zones? 

IECC Climate Zones are categories that distinguish different counties based on climatic characteristics. These zones consider various factors such as temperature, humidity, wind patterns, and solar radiation.  


The 2021 version includes eight zones labeled one through eight, with lower-numbered zones representing warmer climates and higher numbers representing cooler areas. These are further differentiated as moist, dry, and marine. For example, Cleveland, Ohio is in the 5A climate zone — it is on the colder end of the spectrum and moist.  


Overview of Changes in IECC 2024 

Staying on top of how climate zones change is critical for owners and developers — they dictate building standards and best practices for sustainable design. Though still in development, initial ideas for the 2024 update indicate several changes affecting energy efficiency guidelines. A few broad changes that we expect include: 


1. Refinement of Existing Zones 

The IECC always considers changing climate patterns in its code development. This means that boundaries of existing climate zones will likely be refined to better reflect current climate conditions. This could include subdividing current zones or reclassifying areas into different zones. For example, in the 2021 standard 10% of counties were reclassified, with the vast majority shifting to lower climate zones to reflect general warming trends across the U.S.  


2. Increased Efficiency Requirements 

Between 2006 and 2021, the IECC increased its building efficiency requirements by an average of 8% per update cycle. It is likely that this trend will continue in the 2024 update. This requires better energy management practices through improving building envelopes and heating and cooling systems.  


3. Building Electrification 

The IECC is expected to make electrification more central to building design. It aims to move away from using fossil fuels as a direct energy source with electricity as the primary alternative energy source. This paves the way for renewable energy sources, like onsite and utility-scale solar, to power entire buildings. It will encompass most energy-reliant systems, from water heaters to electric vehicle charging infrastructure. 


While these are just a few changes we may see in the 2024 update, here is a more extensive list of proposed updates. 


How Will Changing Climate Zones Impact Buildings? 

Climate zones provide guidelines on what energy-efficient building practices and systems are necessary for buildings. This makes them relevant for two primary reasons: building code compliance and resource-efficient design. Both of these aims work hand in hand.


Building codes are mandatory and are dictated by local and state regulations. Many counties already rely on climate zone information and IECC's building efficiency recommendations. Furthermore, the number of states adopting more rigorous IECC standards is rising due to the Inflation Reduction Act setting aside $1 billion in funding to help municipalities adopt the standard. In simple terms, if a climate zone changes, building codes may follow suit. Developers will need to understand the changes and implement them in their projects. 


Beyond compliance, understanding climate zones are necessary when developing sustainable structures or pursuing sustainability certification, like LEED. In this case, developers want the most impactful and cost-effective sustainability strategies. Climate zones help determine what is best in a given area. For example, it may be helpful to include a heat pump as a low-energy, cost-effective alternative to heating gas for a building in climate zone 2, yet not viable for a building in climate zone 6 where temperatures are below freezing for extended times of the year.


Stay On Top of Climate Zone Changes in 2024 

The updating of IECC climate zones reflects the dynamic nature of our environment. As the climate changes, so must our approaches to building and maintaining energy-efficient structures. These modifications are not mere compliance issues; they represent opportunities to align construction with sustainability principles. Efficient building practices can be a financial and social boon for developers. 


Emerald Built Environments understands these changes. We're here to ensure that building owners and developers not only stay current with these evolving standards but also leverage them to achieve more sustainable and efficient buildings. Stay ahead of the curve and learn how we can help you navigate these changes and achieve a more sustainable build. 

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