This past week, a Missouri House committee advanced HB580, a bill that would place statewide limits on residential building energy codes and potentially make it illegal for St. Louis area municipalities to enforce portions of locally adopted ordinances.
If made into law, the bill would weaken the 2018 suite of International Code Council (ICC) building codes adopted by the City of St. Louis nearly five years ago.
The changes are aimed at energy code provisions for new residential dwellings and would roll certain insulation and air-sealing standards back to levels more consistent with the 2009 energy code.
The primary text of HB580 reads:
No community shall adopt any ordinance, resolution, regulation, code, or policy that:
(a) Prohibits, or has the effect of prohibiting, framed cavities in new dwellings from being used as ducts or plenums; or
(b) Requires, or has the effect of requiring:
a. New dwellings to have a wood frame wall cavity insulation R-value greater than thirteen;
b. New dwellings to utilize exterior continuous insulation;
c. New dwellings to have a ceiling insulation R-value greater than thirty-eight; or
d. New dwellings to have a maximum air leakage rate less than five air changes per hour.
Any ordinance, resolution, regulation, code, or policy adopted in violation of this subsection shall be null and void.
The bill does not prohibit owners or homebuyers from choosing to upgrade their insulation, yet there is no requirement that builders disclose efficiency data or offer upgrades in the design phase when critical performance decisions are solidified.
In written testimony opposing HB580, Energy Consultant, Steve O’Rourke elaborated, “The most cost-effective time to invest in energy efficiency is during initial construction. Builders who build to minimum code are doing no favors for their customers, who may not be educated about the cost savings they’ll realize if the building is built to higher standards. Once the building is built, it is often cost-prohibitive to upgrade the insulation and other features of the building envelope.”
A memo from the Sierra Club warns that HB580 would make it easy for builders to charge a premium for upgrades, “This practice ensures energy efficiency is only available to those who can afford the upgrades and disproportionately negatively impacts low-income families and renters in multi-family housing units.”
HB580’s proposed wood framed wall cavity insulation R-value of 13 would be a downgrade from R-20 as currently required by some municipal ordinances. Notably, R-13 is also the level of cheap fiberglass batt insulation that can easily fit into a 2×4 wood framed wall. R-20 generally requires upgrading to 2×6 wood studs (or a higher-grade insulation, likely continuous). The 2×4 vs 2×6 debate lives on in Missouri, despite that fact that most local architects (this author included) have not designed a 2×4 wood framed home in decades, if ever. And it’s not just about energy efficiency – a 2×6 wall is generally stronger and superior at resisting wind loads.
The proposed ceiling insulation limit of R-38 would be a reduction from R-49 as currently required by City of St. Louis and a handful of local municipalities.
HB580’s air leakage allowance of five air changes per hour would be more lenient than newer code limits of three air changes per hour.
For some metro St. Louis jurisdictions (St. Charles County, St. Louis County & Jefferson County), HB580 restrictions are roughly on par with current residential energy codes – thanks to many hidden amendments, often the result of lobbying from the local Home Builders Association.
Regardless of current codes, HB580 would prevent unamended adoption of future energy codes, thus limiting building performance and access to IRA funding. Municipalities with their hands tied by HB580 could miss out on Inflation Reduction Act (IRA) funding which includes $1 billion in funding for state and local governments that support unamended adoption of the 2021 International Energy Conservation Code (IECC) and related energy codes. The City Council of Kansas City recently approved adoption of the 2021 IECC, effective July 1, 2023
Missouri, the original “home rule” state, has always been big on local control. When it comes to codes, we take our hands-off approach seriously as one of only 7 states without a statewide building code. This approach has famously allowed some (mostly rural) areas of Missouri to exist without any building codes at all. Many Missouri counties do not require residential building permits.
Home rule also gives Missouri communities the freedom to adopt modern building codes – and most cities, towns and some counties have done so for decades.
Why then is a state without a building code suddenly trying to make local building ordinances null and void? Who is behind this bill?
Supporters of HB580 include the Kansas City Regional Association of Realtors and The Home Builders Association of Greater Kansas City and the Building Owners & Managers Association of Kansas City
HB580 sponsor, Rep. Dan Houx, represents part of Johnson County (District 54) in the Missouri House of Representatives. Houx’s biography states that “in addition to his legislative duties, Houx has been a real estate developer/ homebuilder and a licensed realtor,” and was a 2018 recipient of a 2018 St. Louis Homebuilders Association Award. Rep. Dan Houx resides in Warrensburg, Missouri. Like St. Louis, the City of Warrensburg adopted the suite of 2018 ICC building codes nearly five years ago.
Opponents of HB580 include organizations such as the American Institute of Architects (AIA) St. Louis, AIA Kansas City, Missouri Gateway Green Building Council, Missouri Coalition for the Environment, Municipal League of Metro St. Louis, Sierra Club Missouri Chapter.
The North American Insulation Manufacturer’s Association (NAIMA) and Polyisocyanurate Insulation Manufacturers Association are also opposed. For product manufacturers, energy-efficiency means increased sales and Missouri jobs. Owens Corning & CertainTeed both operate insulation manufacturing facilities in Missouri.
Supporters of HB580 argue that present day energy codes are cost prohibitive and some go as far as saying that energy codes are a government overreach with few health or safety benefits.
Are current building codes prohibitively expensive? If that were the case, one would have expected to see the pace of construction in St. Louis slow down five years ago with the adoption of 2018 codes. Instead the opposite is true – despite a pandemic and inflation.
A 2021 government study entitled “Cost-Effectiveness of the 2021 IECC for Residential Building in Missouri” takes a deep dive into the true cost of residential energy codes throughout the various climate zones of Missouri. The study concludes that there would be a state average Life-Cycle Cost Savings of $13,298 per new dwelling by upgrading to the 2021 IECC (compared to 2009 IECC) and a state average simple payback of just 8.3 years.
What about health and safety? Indoor air-quality is irrefutably a health concern. Air-tight homes with code-compliant ventilation have been found to reduce indoor air pollution and improve the health of residents. During power outages, energy-efficient homes tend to maintain safe and comfortable temperatures, allowing residents to stay put longer.
Missouri House Bill 580 is a misguided attempt at cutting first-costs of new construction at the expense of homeowners and renters who will be stuck with higher monthly utility bills for the life of the home.