Building Codes Don’t Have to Be Boring
With growing concern over climate change and severe weather incidents, seen across 150 countries during Climate Strike Fridays, building efficiency is in the spotlight.
Buildings account for approximately 40% of energy used in the United States and over one-third of carbon missions – which is why it’s not effective to think of energy policies and climate action without addressing building efficiency. Because of this, building codes aren’t boring, and energy codes are more important than you might think.
Building energy codes are key to a sustainable future
Building energy codes and standards are minimum efficiency requirements for the design and construction of new buildings and renovations to existing buildings. They are fundamental components of construction regulations that oversee all aspects of buildings, from the way you build wall systems to electrical safety and fire protection. Like all codes, energy codes are about health, safety, and durability.
The two energy codes we follow most closely for energy efficiency and durability are the International Energy Conservation Code® (IECC) and ANSI/ASHRAE/IES Standard 90.1 (ASHRAE Standard 90.1). The IECC applies to all buildings. ASHRAE Standard 90.1 applies to commercial buildings, which are considered buildings other than single-family dwellings and multifamily buildings three stories or fewer in height above grade (e.g., residential buildings).
What’s the difference? ASHRAE 90.1 is a minimum standard of energy efficiency, not a code. The IECC is a model energy code that references ASHRAE Standard 90.1. IECC adopts the latest ASHRAE Standard, plus any addenda and new data. This means that IECC is ultimately a more stringent code than the ASHRAE Standard. Some jurisdictions have also allowed following ASHRAE 90.1 as a path to building code compliance.
Once the model code is developed, it’s up to cities and states to adopt it. The IECC is used by more than 40 states, although not all are using the latest version. It also is recognized by the Department of Energy (DOE) and cited in federal law. This year has seen a growth in the number of states and cities adopting policies. In May, the 2018 IECC became law across the state of Illinois. Other leaders include California, Washington, Vermont, and New York, as well as cities such as Boulder, the District of Columbia, and Scottsdale.
Codes with energy requirements that are strongly enforced are vital tools for states and cities when trying to cut carbon emissions. The IECC Toolkit contains resources to help ICC members and member jurisdictions promote the adoption, implementation, and enforcement of commercial and residential building energy codes.
Big changes stirring
Efficiency improvements to buildings are the most cost-effective and influential measures we can take to reduce energy consumption and cut greenhouse gas emissions. Earlier this year, a group of building industry professionals consisting of code officials, manufacturers, designers, and advocates met to propose and debate amendments to the 2021 International Energy Conservation Code (IECC). Successful amendments stemming from these discussions will drive future construction practices and building efficiency and resiliency. Later this month, Public Comment Hearings will be held in Las Vegas, Nevada, followed by online governmental member voting mid-November.
The Public Comment Hearing results will be posted here.
As city and code officials prepare to vote, below are significant proposals related to the building envelope that are likely to become a part of the 2021 IECC.
Air barriers & air leakage
To make a building more energy efficient and resilient, the envelope has to be the number-one priority. For this reason, the committee focused on the issue of air barrier placement and adding mandatory thermal envelope air leakage testing to the code, as it has not been comprehensively improved since the 2012 edition, even though ASHRAE has continued to make cost-effective improvements during that same period.
Air leakage control is an important but commonly misunderstood component of the building envelope and energy-efficient house.
An airtight house will:
- Have lower heating bills due to less heat loss;
- Have fewer drafts and be more comfortable;
- Reduce the chance of mold and rot because moisture is less likely to enter and become trapped in cavities;
- Have a better-performing ventilation system; and
- Potentially require smaller heating and cooling equipment capacities.
Air tightness testing can result in more attention to air barrier sealing and significantly reduced building leakage. Currently, the residential energy code requires air tightness testing for residential buildings three stories or fewer in height to ensure proper tightness and a controlled indoor environment. There is no testing requirement in the commercial energy code for residential buildings four stories or more in height (e.g., apartments, dormitories, hotel guest rooms). Industry standards affecting these buildings have historically relied upon visual verification, as well as material and assembly requirements.
The purpose of this code change proposal is to reduce energy costs for commercial building owners and improve long-term energy efficiency by adopting the more efficient and cost-effective opaque envelope requirements from ASHRAE Standard 90.1-2016 or the IECC for slab-on-grade floors in climate zones 3-6.
The building envelope typically remains the same for many years after construction and it is particularly important to capture as much cost-effective energy efficiency as possible at construction. After all, the intent of the IECC (C101.3) is to “regulate the design and construction of buildings for the effective use and conservation of energy over the useful life of each building.”
In a public comment on IECC: C402.5.1.2, Duane Jonlin of the Seattle Department of Construction Inspection encouraged support of the Committee decision to require testing of air barriers. In his statement, he noted “the current code does little to control air leakage, because the problem is not air leaking right through the materials and assemblies themselves, but rather through the joints between these elements and penetrations through them.” He further explained, “These leaks cannot be located or measured by visual inspection – the only way to know how much air is leaking through your building, and to start reducing that leakage, is to actually test it. Our experience here in Washington state is that buildings can pass easily, and we are now in the process of tightening up the test standard even further.”
Although local jurisdictions have unique needs, we can look to those who have successfully implemented the IECC and witnessed significant impact early on. Seattle, New York, California, and British Columbia are examples of noteworthy code improvements that aim to ensure new construction and major building renovations have a long-term impact on reducing emissions. Once introduced, the new 2021 IECC will pave the way for a record number of states and cities introducing innovative policies that will ultimately improve building performance and deliver carbon emission reductions.
For a complete overview of energy codes coming to a city near you, read Kimberly Cheslak’s Top 5 Energy Efficiency Proposals for the 2021 IECC. For more expert insights on which performance standards matter most to achieve airtightness, watch John Straube’s 3-minute video.
Finding ways to reduce greenhouse gas emissions is always a challenge but advancing building and energy codes is a step in the right direction, and holds more value than many give credit to. And certainly not boring!
Stay tuned for more information on the release of the 2021 IECC model.