Missouri Residential Building Energy Code Construction Practices Study

The Missouri Department of Natural Resources' Division of Energy partnered with the Midwest Energy Efficiency Alliance (MEEA) to collect data about Missouri residential construction practices as they relate to the energy code.

As a condition for Missouri’s acceptance of State Energy Program (SEP) funds, the American Recovery and Reinvestment Act (ARRA) required a plan for compliance with the 2009 International Energy Conservation Code (IECC) across 90% of new and retrofitted building stock by 2017. The results of this study will be used as the basis for determining statewide compliance with this ARRA requirement for residential buildings.

Data collection for the study occurred from April 6 through June 30, 2016, through in-field site visits to a random sample of new, unoccupied, single-family homes across Missouri. Data was generally collected at the insulation stage of construction and at the final stage of construction.

All data collected was anonymous, scrubbed of all identifying information (such as builder name and address), and analyzed on a comprehensive statewide level. Individual home data has not been shared with building officials and data collectors did not collect enough information on any single home to be able to verify whether that individual home complied with the local energy code.

The data was collected using a methodology acceptable to the U.S. Department of Energy (US DOE) Pacific Northwest National Laboratory (PNNL). For information on studies that have occurred in eight other states using this methodology, see the Residential Building Energy Code Field Study. The sampling plan methodology was based on 2015 Census permit data of single-family homes, weighted by county, randomly selected and was a representative cross-section of construction.

The study documented observations of the following 9 key measures:

  • Envelope Tightness (ACH50)
  • Window Solar Heat Gain Coefficient (SHGC)
  • Window U-Factor
  • Exterior Wall Insulation
  • Ceiling Insulation
  • High Efficacy Lighting
  • Foundation Insulation
  • Duct Leakage (CFM25)
  • HVAC Right Sizing (Manual J Block Load)

On-site data collection was performed by The Cadmus Group, which collected field data for this methodology in several other states. Data collectors provided minimal disruption to builder operations while on-site. Matt Belcher, a St. Louis based home builder, was the Data Collection Facilitator for the project. Matt contacted permitting jurisdictions and builders throughout Missouri to secure site access for the study.

The information collected in this study will help home builders, sub-contractors, and other stakeholders better understand where challenges exist and provide a focus for improving the quality of the local built environment.

Results: The potential demand savings from residential energy code compliance improvements (2009 IECC) associated with the observed measures is estimated to range from 5.3 to 7.5 megawatts.

The PNNL analysis of measure level energy consumption savings estimates total electricity savings of 11,445,719 kWh and natural gas savings of 1,485,512 therms. Total energy cost savings are estimated to be over $3 million (over $300 per home per year on average) when using the 2009 IECC as a baseline. (Note that individual savings would vary greatly depending on which measures were non-compliant in a given home.)

For more information, please contact energy@dnr.mo.gov.