MO has not adopted statewide energy efficiency codes for residential or commercial buildings.
Building energy codes reduce energy use, but customer behavior can offset projected energy savings.
With updated energy codes, new homeowners in MO are projected to save 26% or $677 annually on their utility bills.
Residential and commercial buildings consume 75% of the electricity and 40% of the total energy used in the U.S. (Langevin & Wilson 2025). Building energy codes establish minimum energy efficiency standards for residential and commercial buildings (MO Department of Natural Resources n.a.). They cover insulation, windows, heating, ventilation, air conditioning, lighting, and other building features.
Forty states and D.C. have adopted statewide building energy codes for residential buildings and commercial buildings (U.S. Department of Energy/Energy Efficiency and Renewable Energy (DEO/EEER) 2024a; Figure 1). Most states have adopted the International Energy Conservation Code (IECC) as their residential energy code. Before adopting the IECC, jurisdictions often modify it to reflect regional building practices (Barlett et al. 2003). MO has not adopted statewide energy codes for residential or commercial buildings, but local jurisdictions have the option to adopt their own energy codes (DEO/EEE 2024b). Many major municipalities have adopted energy codes such as St. Louis, St. Louis County, Kansas City, Springfield, Independence, and Columbia. MO’s state government has the authority to set minimum energy efficiency standards for state buildings (RSMo 8.812). State-owned commercial buildings must meet the 2012 IECC (DEO/EEE 2024b).
Figure 1. Residential building energy codes adoption. Categories correspond to characterization of states to a specific IECC code edition. AZ and HI do not have statewide codes, but a review of codes in place across the state indicates that 80% of the population is covered by codes at this level. Figure from the DOE/EERE (2024a).
Building energy codes decrease electricity consumption. One study observed a 13% decrease in per capita electricity use with code adoption, and a 17% increase in per capita natural gas use in 48 states from 2015-2017 (Kellog & La Cumbre-Gibbs 2023). These changes in natural gas use are likely due to greater natural gas access and usage for heating, cooling, and water heating in many states.
In Gainesville, FL, residences constructed after Florida’s 2002 energy code implementation had a 4% decrease in electricity consumption and a 6% decrease in natural gas use compared to residences constructed before the code (Jacobsen & Kotchen 2013). On average, it took between 3.5 and 6.4 years to receive a return on investment. A follow-up study using residential billing data over 11 years (2004-2014) shows that, while the initial estimates of electricity savings from the energy code change diminished over time, the energy savings for natural gas were constant over time (Kotchen 2017).
A California study found that energy savings were lower than the projections at the time regulations were implemented (Levinson 2016). This result is attributed to a rebound effect where the decline in energy price results in increased energy use from households, offsetting a portion of projected energy savings (Aydin et al. 2017).
From 2010 to 2040, energy codes are projected to save consumers an expected $182 billion in reduced utility bills across the U.S. (Tyler et al. 2023). These savings come from improvements in residential and commercial energy efficiency mandated by energy codes.
Energy efficiency investments may raise initial construction costs (DOE/EERE 2021). However, a survey found that buildings constructed under strict building codes have between 3% and 10% higher market value (Papineau 2013).
By upgrading to updated energy codes, a new homeowner in MO can expect to save 26% or $677 annually on their utility bills (Salcido et al. 2021). Considering both initial and ongoing construction, maintenance, other costs, and energy savings, the average home in MO is expected to save $13,298 over a 30-year lifetime (DOE/EERE 2021).
In MO, savings for commercial buildings, public and private, are $3,983/ksf and $3,501/ksf (ksf=thousand square feet) respectively over a 30-year period (DOE/EERE 2021). These savings are calculated by comparing the present value of energy savings for a building constructed under the updated code to those constructed under the previous code, then subtracting the incremental construction and other costs over a 30-year analysis period (Salcido et al. 2021).
References
Aydin E, Kok N, Brounen D (2017) Energy efficiency and household behavior: the rebound effect in the residential sector. The RAND Journal of Economics,48(3):749-82. https://www.jstor.org/stable/26305461
Bartlett R, Halverson MA, Shankle DL (2003) Understanding building energy codes and standards. Pacific Northwest National Lab (PNNL). Richland, WA. https://www.pnnl.gov/main/publications/external/technical_reports/PNNL-14235.pdf
Jacobsen GD, Kotchen MJ (2013) Are building codes effective at saving energy? Evidence from residential billing data in Florida. The Review of Economics and Statistics, 95: 34–49. https://doi.org/10.1162/REST_a_00243
Kellogg KA, La Cumbre-Gibbs N (2023) The impact of state level residential building code stringency on energy consumption in the United States. Energy and Buildings, 278:112607. https://www.sciencedirect.com/science/article/abs/pii/S0378778822007782#b0040
Kotchen MJ (2017) Longer-run evidence on whether building energy codes reduce residential energy consumption. Journal of the Association of Environmental and Resource Economists, 4(1):135-53. https://www.journals.uchicago.edu/doi/full/10.1086/689703
Langevin J, Wilson E (2025) Technology Innovation Opportunities for the US Buildings Sector. Department of Energy and Office of Energy Efficiency & Renewable Energy. Link
Levinson A (2016) How Much Energy Do Building Energy Codes Save? Evidence from California Houses. American Economic Review, 106 (10): 2867–94. https://www.aeaweb.org/articles?id=10.1257/aer.20150102
Midwest Energy Efficiency Alliance (n.a.) Missouri Building Energy Codes. Missouri Building Energy Codes | Midwest Energy Efficiency Alliance
MO Department of Natural Resources (n.a) Energy Codes. https://dnr.mo.gov/energy/efficiency/codes-jurisdiction/training-resources
Papineau M (2013) Energy codes and the landlord-tenant problem. UC Berkeley: Department of Agricultural and Resource Economics. https://econpapers.repec.org/paper/cdlagrebk/qt2bq3x1t6.htm
Salcido VR, Chen Y, Xie Y, Taylor ZT (2021) Cost-Effectiveness of the 2021 IECC for Residential Buildings in Missouri. Pacific Northwest National Laboratory. Link.
Tyler M., Poehlman EA, Winiarski DW, Niemeyer JM, Rosenberg MI (2023). Impacts of Model Building Energy Codes. Pacific Northwest National Laboratory. https://doi.org/10.2172/2229430
U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (DOE-EERE) (2021). Building Energy Codes: Missouri. EED_1365_BROCH_StateEnergyCodes_states_MISSOURI.pdf
U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (2024a) Building Energy Codes Program. State Portal | Building Energy Codes Program
U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (DOE-EERE) (2024b). Building Energy Codes Program: Missouri. https://www.energycodes.gov/status/states/missouri
