During the past five years, the U.S. has experienced 90 weather- and climate-related disasters that exceeded $1 billion in damages. As extreme weather events caused by climate change become more frequent and intense, governments and organizations are turning their focus toward improving climate resilience policies.
In recent years, buildings have become a focal point in efforts to improve climate resiliency. The rise in greenhouse gas (GHG) emissions is a substantial driver in the changing climate, and the building and construction sector is the largest contributor, accounting for roughly 40 percent of global emissions. At the same time, the built environment serves an important role in protecting communities from the impacts of climate change.
Because of this, the adoption and implementation of modern energy codes has become increasingly important to help mitigate GHG emissions and lower energy use while enhancing resilience. Ensuring buildings use energy efficiently is essential for protecting human health, economic prosperity and reducing the impacts of the changing climate.
RESILIENCY IMPACTS OF ENERGY CODES
To date, building energy codes have primarily focused on reducing energy costs, energy use and emissions. However, as adapting to the impacts of climate change becomes a priority, energy codes now also are being recognized for their contributions to resilience. Some of these resilience elements include energy efficiency, fire safety, moisture management, durability and extreme weather protection.
Enhancing resilience in buildings through energy efficiency is a major goal for the U.S. Department of Energy’s (DOE’s) National Laboratories. To help aid the development of improved resiliency initiatives, National Laboratories conducted a 2023 study, “Enhancing Resilience in Buildings Through Energy Efficiency”, to quantify the value of building energy codes in regard to extreme weather-hazard resilience. The results of this study are expected to be published this summer. (Read about the study.)
Through its research, DOE found that energy codes have a direct impact on energy-resilience outcomes. These impacts include increased thermal resistance within the building and the ability to maintain healthy levels of ventilation and indoor air quality, which is a primary source of moisture and durability issues.
In nearly every situation, improving efficiency in residential buildings to meet or exceed current energy-code requirements saves lives during extreme-temperature events. Furthermore, increasing efficiency in existing single-family buildings to meet code requirements of the 2021 International Energy Conservation Code (IECC) increases habitability by as much as 50 percent during extreme cold and by up to 40 percent during extreme heat.
SUPPORTING PASSIVE SURVIVABILITY THROUGH ENERGY CODES
Building energy codes also support passive survivability or the ability of a building to remain habitable in the face of hazardous events, such as extreme-temperature events. Through provisions for efficient buildings and HVAC, refrigeration equipment, as well as guidance on shading and reducing solar heat gain, energy codes can reduce the impacts of and enhance occupancy during such hazardous events.
The need for passive survivability may arise during extreme heat or cold events when a community’s power grid is stressed. Reduced energy demand to obtain comfortable temperatures through increased building efficiency can also enhance the resilience of the energy grid.
Through passive survivability, community and individual resilience are enhanced by providing a safe and comfortable indoor environment even during extended periods of disruption or emergency.
These findings emphasize how implementing modern energy codes is central to both mitigating climate emissions and energy use while enhancing resilience.
DEVELOPMENT OF BUILDING ENERGY CODES
Energy codes have made significant improvements in energy savings since their initial development roughly 40 years ago. For example, the Code Council updates the IECC every three years to reflect new knowledge, advanced technologies and evolving human behavior to provide model codes that promote building safety, sustainability and resiliency.
It has been proven that communities that regularly adopt and implement modern energy codes and standards provide cost savings for residents and businesses while improving overall health and resilience. The Pacific Northwest National Laboratory (PNNL) produced a final determination on the 2021 IECC that found a 9.4 percent energy-savings improvement and an 8.7 percent improvement in carbon-emissions reduction for residential buildings relative to the 2018 IECC—ultimately saving homeowners an average of $2,320 over the life of a typical mortgage. (Read the determination.)
PNNL also produced an analysis on the 2021 IECC commercial provisions that found site energy savings of 12.1 percent and a 10.2 percent GHG emissions savings for commercial buildings relative to the 2018 IECC. The determination concluded that, on a national weighted average basis, the 2021 IECC is 6.5 percent more efficient for site energy use and saves 3.3 percent more in energy costs than ASHRAE Standard 90.1-2019.
Enhanced energy codes and regulations, often referred to as “stretch codes” or “reach codes”, can be used to further support building resiliency. These codes provide a means to advance energy efficiency and reduce emissions in a jurisdiction, delivering a tool that allows cities and counties with ambitious climate goals to move forward at a quicker pace than others in the state.
Some examples of these stretch codes include:
- The State of Massachusetts’ Stretch Energy Code and Municipal Opt-in Specialized Code: The stretch code emphasizes energy performance while the Specialized Code ensures new construction is built consistent with Massachusetts’ greenhouse gas limits. These stretch energy codes provide flexibility to jurisdictions and surpass the proposed base code modeled on the 2021 IECC, which will go into effect later this year.
- The Inflation Reduction Act: The Inflation Reduction Act Building Codes Technical Assistance program will make $670 million available to adopt a building energy code that meets or exceeds the zero-energy provisions in the 2021 IECC code or other codes and standards with equivalent or greater energy savings. This funding should be available later this year and the Code Council is prepared to work with jurisdictions to access this funding.
- The 2021 International Green Construction Code (IgCC): The IgCC, which is a collaboration between the Code Council, ASHRAE, USGBC and IES, is a stretch code based on ASHRAE Standard 189.1 and includes chapters on advanced energy efficiency and an appendix that aligns code requirements with LEED requirements. The IgCC also includes a chapter on materials and resources related to embodied carbon as that strategy continues to pick up momentum. Future editions of the IgCC are expected to include even more resilience- focused measures.
IMPORTANCE OF BUILDING ENERGY CODES
Buildings play a critical role in GHG emission reduction to mitigate the negative impacts
of a changing climate. Recognizing the important role of building codes, standards and building safety professionals in ensuring safe and resilient communities, President Biden proclaimed May 2023 as National Building Safety Month. The proclamation discusses how building energy codes “improve energy efficiency and indoor air quality in federally supported housing and make [these] properties more resilient to climate impacts.”
Policies at the state and local levels to achieve zero-emission buildings and enhance community resilience must include a strong focus on current and future buildings. The adoption and effective implementation of building energy codes are central to the realization of a resilient future.