Energy codes have big impacts on how homes are built and what goes into them. In fact, with each new release of The International Energy Conservation Code®, we’re seeing dramatic shifts in the way builders are tackling the building envelope. Why is that important to us? Because as building codes change, so do building practices. And the building materials needed to meet those needs.
Here’s what current codes have to say about the state of building practices and the role tape will play.
What is the IECC?
The International Energy Conservation Code ® (IECC) is one member of the International Code Council, which sets the bar for energy efficiency in commercial and residential buildings in the U.S.. In fact, there are ICC codes for Plumbing, Swimming Pools and Spas, Fire Codes, and more. When it comes to Residential Construction, the IECC:
- Applies to new and renovated buildings
- Sets minimum requirements for energy features and performance
- Reduces energy use and polluting emissions over the life of complying buildings
- Benefits homeowners and society by improving cost-effectiveness, comfort, and durability
- Covers both residential and commercial buildings
Published in November 2017, the 2018 IECC is the most recent version. The code establishes a baseline for energy efficiency by setting performance standards for the building envelope (defined as the boundary that separates heated/cooled air from unconditioned, outside air), mechanical systems, lighting systems, and service water heating systems in homes and commercial businesses.
How Better Building Codes Are Developed
Building energy codes are not developed by the US Department of Energy (DOE). They are, in fact, developed through two independent entities: the International Code Council (for residential and commercial buildings) and ASHRAE (for commercial buildings). David Cohan, Building Energy Codes Program Manager, DOE, details the residential code process here:
How it works: The International Code Council (ICC), a nonprofit organization, develops a suite of model construction codes, which all 50 states have adopted some version of. One of these model codes is the International Energy Conservation Code—which the ICC updates every three years through a public consensus process.
Here are the steps:
- Public submits proposals: When the cycle kicks off, any interested party can submit to the ICC, at no cost, a list of changes they’d like to see to the code. Participants typically include code officials, design professionals, code consultants, trade associations, builders and contractors, manufacturers and suppliers, and government agencies.
- First public hearing: The ICC compiles the list of all code change proposals received and publishes them. This is followed by the first of two public hearings, where stakeholders can debate proposals’ merits. At the first hearing, proponents and opponents of proposals make their arguments before a committee of experts assembled by the ICC that will vote on each proposal. The committee’s options are to approve a proposal as submitted, modify it and approve as modified, or disapprove it. The residential chapter and commercial chapter have separate committees.
- Comment period: Between the two public hearings, the public can submit written comments on the committees’ recommendations with suggested changes to any proposals. If no public comment is submitted on a proposal it is placed on a consent agenda for the second public hearing (if it was approved by the committee) or it is no longer considered in the process (if it was disapproved by the committee).
- Second public hearing: At the second public hearing, stakeholders present their arguments to the ICC Governmental Member Representatives who will cast the final votes on all proposals. The large majority of these representatives are employees of city and county building departments. Others are from state governments. Federal government agencies, including DOE, can also vote. Only proposals which received public comments are discussed.
- Finalize new edition: After the hearing, the ICC representatives vote on each proposal, with all accepted changes entered into the new published edition of the IECC. States have the option to adopt the new codes or continue with their current codes.
Where does the Department of Energy (DOE) fit in? The DOE’s Building Energy Codes Program is statutorily required to participate in the IECC code development process by submitting code change proposals and participating in the review process. All of DOE’s proposals are screened to be cost-effective based on its energy and cost analysis methodology.
The State of the States: What Codes are in Place, and Where
As of December 2018, only four states — California, Massachusetts, Oregon, and Washington — have minimum requirements more efficient than the 2012/2015 IECC.
Eight states — Delaware, District of Columbia, Florida, Maryland, Nevada, New York, Texas, and Vermont — adhere to the 2012/2015 IECC.
Sixteen states are between the residential 2009 IECC and 2012/2015 version, and 23 states are still lagging behind the 2009 codes. You can find up-to-date state adoption here.
Here’s the good news: We’ve seen a rapid jump in states moving from 2009 directly into 2015 IECC standards over the past few years. While almost half the states are operating at 2009 or below, the indication is that many states are considering a move directly into 2015 requirements.
There are no direct penalties for not adopting current IECC code, rather it is a state-by-state determination. Where does your state rank? Here’s a fun link describing each state’s code adoption process: https://www.iccsafe.org/
2009-2018: Which Code Changes to Know
If you take away only one thing from this post, it should be this: sealing the building envelope has become the main line of defense in energy efficiency and subsequent building codes. Though sealing the building’s thermal envelope has been required by the energy code, in some form or another, for many years, the rules presented before 2009 were vague and only mandated that areas of potential air leakage such as joints, or utility penetrations be sealed with a durable material like caulking, gasketing, or weather stripping. Over the years, IECC code has gotten increasingly specific:
2009. The 2009 IECC offers an air-sealing checklist (Table N1102.4.2) for builders detailing 17 points for visual inspection. At thsi point, builders could opt to have a blower door test performed to meet IECC, during which, they need to achieve a leakage rate of less than or equal to 7 ACH at 50 Pascals.
2012. According to Pacific Northwest National Laboratory Engineer Vrushali V. Mendon, “The 2009 checklist was no longer sufficient; at the end of the day, a builder has to demonstrate they really are below that infiltration threshold.
As a result, the 2012 IECC makes a blower door test mandatory, and requires air leakage rates of less than or equal to 5 ACH in Climate Cones 1 or 2, and less than or equal to 3 ACH in Climate Zone 3-8, at a test pressure of 50 Pascals. The code also notes that a “continuous air barrier shall be installed in the building envelope,” that the “exterior thermal envelope contains a continuous air barrier,” and that “breaks or joints in the air barrier shall be sealed.”
2015. IECC 2015, is most noted across the homebuilding world for establishing an “Energy Rating Index.” Known as RE188 in technical circles, this is, in essence, a HERS (Home Energy Rating System) Compliance Pathway. Homes that meet the mandatory code requirements and attain a specified HERS Index between 51-55 based on climate zone are considerated compliant. The Residential 2015 IECC maintains its requirement for blower door testing, but now references two standards for the required blower door test, ASTM E 779 and ASTM E 1827. A more descriptive visual air leakage checklist is also included.
The 2015 IECC also places emphasis on a continuous air barrier, which must be aligned with the thermal building envelope, and must be inspected. Sealing methods between dissimilar materials must allow for differential expansion and contraction. Which is of special interest to us, as tape manufacturers!
2018. Continuing the emphasis on air leakage and the building’s thermal envelope, the latest version of IECC 2018 requires both a whole-house pressure test and field verification of items listed in Table R402.5.1.1.
“In fact 2012, 2015, and 2018 IECC insulation levels are all the same,” explained Joe Nebbia of Newport Partners LLC, in a presentation for the DOE. “And so that’s our mandatory minimum, and quite frankly, we’re pretty happy with that level. The code has gotten to a point where we’ve got a pretty robust building envelope as far as what’s required in insulation, at least as far as a minimum requirement.”
A significant portion of the 2018 International Energy Conservation Code changes have been adopted to align respective codes more closely with ASHRAE 90.1 and/or current federal minimum efficiency standards, according to the Center for Advanced Construction Information Modeling/University of Florida.
What it All Means for Tape
So what does all this have to do with tape strategy, and how you build?
All this emphasis on air sealing in codes translates into better information for us.
“As air tightness and infiltration become a more primary aspect of codes, I expect to see a lot more studies on tape use,” says Mendon.
A notable surge in types of tape on the U.S. market and research and experimentation with its effectiveness is occurring. New tapes that act as air barriers, but are vapor permeable, are also arriving on the building scene.
Recently, we had the opportunity to discuss tape and codes with Doug Horgan, Vice President of Best Practices at BOWA, who had this to share:
“When Maryland adopted the 2012 IECC, with the 3.0 ACH air leakage test requirement, a lot of builders switched to taped sheathing systems as an air sealing method. In Virginia, building envelope leakage requirements have been static for several code cycles. Blower door tests aren’t required. However, the code being adopted this year (2015 VRC) does require duct leakage testing. Duct joint tapes could become more popular, in one way of looking at it. Having said that, in the current code there’s a visual inspection that joints are sealed; tape is a great way to pass a visual inspection. Of course, there are several other ways to achieve a tighter shell besides taped sheathing, so it’s not a code requirement to use tape, it’s just a method which we’ve seen become much more prevalent than before.”
Mendon concurs. “The code itself doesn’t really tell you exactly how to achieve the tightness goals,” he says. A variety of methods – drywall, spray foam, housewrap, and tape – can all get you to your target. Tape has its advantages as a strategy: it is fast, easy, and can be an affordable approach, according to Mendon. Practice makes perfect. As new tape technology hits the market, it carries with it the promise of a fast and durable solution to the raising performance bar for home envelopes.
Overall, we’ve seen a rapid jump in states moving from 2009 directly into 2015 IECC standards over the past few years. Indeed, major homebuilders are working to have IECC 2015 adopted unilaterally, to better promote a performance, rather than just a prescriptive, approach to energy efficiency. With 23 states still lingering below 2009 IECC codes, the demand for high-performance seaming tape and other products in development will only increase into 2020 and beyond.