We know where the current International Code Council stands, but what does the landscape look like at a state level, where we actually live and build?
We spoke to Joe Nebbia, of Newport Partners LLC, to gain his insight into the sometimes confusing panorama of codes. Nebbia is a building codes expert with 15 years of experience in policy and regulatory analysis, including over a decade spent working on buildings and construction-related issues. He participates in multiple codes and standards developing processes including the International Code Council, ASHRAE, and state codes. In addition to code development and advocacy, Nebbia teaches code classes to builders, designers, code officials, and others in multiple states.
ECHOtape: What’s your take on the differences between the 2015 IECC® and the 2018 code?
JN:As far as the energy code goes, the 2018 code is much more usable than either predecessor code, mostly because of its Energy Rating Index (ERI). While the ERI was included in the 2015 code, it didn’t get used much as a pathway because the target Home Energy Rating System® (HERS) scores were too aggressive. Research by the Florida Solar Energy Center (FSEC) showed that homes built to 2015’s prescriptive codes scored in the 70s on average; 2015 ERI targets were in the 50s, a 20 point divide. The 2018 IECC relaxed those ERI targets back to the 60s, which falls within the sweet spot of the average score for HERS-rated homes nationally.
ECHOtape: What regional differences are you seeing in code adoption and application?
JN: Keep in mind that there are no real regional differences; adoption is always state-by-state.
States tend to have their own approach to code. On the west coast, states tend to use their own code development process. The Florida code usually looks different because it starts with performance and then builds prescriptives. Florida did adopt the 2015 I-codes directly, though amended them for air, given their unique climate.
A number of states don’t have any sort of mandatory state-wide building code –South Dakota, North Dakota, and Mississippi are examples. In North and South Dakota, a code is on the books, but is only voluntary.
Many states adopt a code but then have “home rule,” where individual counties are free to adopt their own provisions. An example of this practice is Colorado. Most of Colorado’s jurisdictions are on 2012 or 2015 I-codes, though the state says 2003 is the most recent code on the books. Texas is similar, allowing jurisdictions to adopt their own code. In most of these “home rule” states, the state code serves as a minimum standard, which jurisdictions can’t weaken. This is true of Maryland, where counties have to adopt a code that doesn’t weaken either the energy or sprinkler provisions of the state.
Tennessee is seeing a lot of jurisdictions adopting new codes and jumping from 2009 to 2015 or 2018 I-codes. Because of that we’re seeing major shifts in how construction is being done; no gradual changes.
Another area of state difference is disaster resistance. Obviously, code here is driven by type of disaster. A great resource to learn more about disaster codes, state by state, is offered by the Insurance Institute for Business and Home Safety®. Access their Building Code Directory and Building Codes by State here.
ECHOtape: After states adopt codes they can amend them? What does that process look like?
JN: Maryland has been a leader in code adoption in general; it is always the first state to adopt the newest version of I-codes. For the first time, Maryland delayed adoption of the 2018 IECC and amended the code for the first time. The amendment allows for blower door test numbers up to 5 ACH 50 under the performance paths. Maryland had adopted 3 ACH 50 under 2012, which is fairly aggressive. This cycle, if a builder is using ERI or the standard performance path, air tightness can be up to 5, with “make-up” or “trade-offs” elsewhere in energy, allowing for more flexibility. This makes the compliance path more attractive, and I’m anticipating a lot of builders using that in Maryland.
Another common state amendment references the 2009 IECC, where residential fire sprinklers were adopted. Many states amend this out of the code; to date, Maryland and California are the only two to have it.
The airtightness requirement is the most common thing you’ll see amended around the country; for example, Illinois, North Carolina, Utah, and Florida all made changes to this provision during their last code adoption.
Until 2019, Maryland stood alone as a state that adopted I-codes without amendments.
Many states adopted 2009 due to funding opportunities. We’re now seeing a lot of states skip 2012 and adopt 2015. Some states are waiting to adopt 2018, which ERI scores have been lowered.
ECHOtape: How is code impacting the use of tape?
JN: From a tape point of view, any jurisdiction adopting blower door requirements will see higher demand for that kind of a product. Likewise, any advanced energy code, where there is less potential to dry naturally and ventilate, there is more demand for a very sophisticated way of keeping bulk moisture out. So we should see a jump in the use of strategies like seaming tape and flashing tape. If you don’t pay attention to your barriers, the building is a disaster waiting to happen.
It’s clear that the standard answer when it comes to code adoption is, “It depends.” Since each state adopts its own code, and some states allow cities or counties to set their own prescriptions, determining building requirements and best practices a very local affair. However, building to the highest level won’t ever get you in trouble, and as Nebbia says: “If you don’t pay attention to your barriers, the building is a disaster waiting to happen.”