The Minnesota Department of Labor and Industry, Construction Codes and Licensing Division (CCLD) recently completed a survey of energy code compliance in Minnesota. The survey helped determine how close the state is to a goal set by the American Recovery and Reinvestment Act of 2009 (ARRA) and identified procedural changes in code enforcement and training needed to improve energy code compliance rates. Funding for the survey came from CARD and the U.S. Department of Energy through ARRA.
The ARRA goal for new and remodeled buildings is to achieve at least 90 percent compliance with the 2009 International Energy Conservation Code for residential buildings, and at least 90 percent compliance with American Society of Heating, Refrigerating, and Air Conditioning Engineers Standard 90.1-2007 for commercial buildings. The Minnesota energy code, last updated in 2009, is not as stringent as the ARRA goal for either residential or commercial buildings.
Commercial buildings meet standard, residential do not. The survey found that Minnesota commercial buildings meet the ARRA standard for 90 percent compliance, while Minnesota residential buildings fell short of meeting the ARRA standard. The shortfall in residential buildings was largely due to the differences between the current, less-stringent Minnesota energy code and the ARRA Standard. A planned 2014 update of the Minnesota energy code to a standard exceeding the ARRA goal will move the residential buildings closer to meeting and perhaps exceeding the ARRA goal.
To conduct the survey, tools developed by the U.S. Department of Energy (DOE) were used, including the “State Sample Generator,” which generated a valid random sample of buildings to be surveyed in each county across the state. For commercial new construction only, the State Sample Generator includes distribution by building size strata. CCLD staff then worked with building officials in those counties to identify new and remodeled buildings that had received building permits since the most recent energy code change of June 2009.
CCLD staff conducted all of the residential and commercial building inspections. For commercial buildings with more complex mechanical and control systems, the CCLD received assistance from the mechanical engineering firm engineering design initiative. Data were entered into another DOE tool called “Score + Store™.” The survey involved 93 residential buildings and 72 commercial buildings. The weighted overall compliance rates, as determined by the Score + Store™ tool, were 76.8 percent for residential and 91.8 percent for commercial buildings (see Table 1).
Building Permit Category
|Average % Compliance||Sample Size|
|Residential New Construction||80.2%||54|
|Weighted Overall Residential Average:||76.5%||Total: 93|
|Commercial New Construction||90.1%||30|
|Weighted Overall Commercial Average:||91.8%||Total: 72|
For commercial buildings, the highest compliance was observed for temperature controls for service water heating systems, energy efficient exit signs, and integration of lighting controls. For residential buildings, the highest compliance was observed for dampers installed on air intakes and exhausts, wall insulation being installed in accordance with manufacturer’s instructions, and installation of programmable thermostats.
For both commercial and residential buildings, common compliance failures found were incomplete heat loss and gain calculations in the initial documents submitted to the building departments for permit application, and a lack of calculations for heating, ventilating, and air conditioning (HVAC) equipment sizing. For residential renovations, very low compliance was found for the required posting of a building energy certificate. For commercial building HVAC projects, very low compliance was found for required submittal of complete sets of plans and specs at the time of permit application and for providing a complete set of operating and maintenance manuals for the building owner.
Final report available. Results of the report not only provide a baseline for ARRA compliance but provide utilities with a baseline and reference for potential inclusion of code compliance efforts within their conservation improvement programs. The report also contains results of Minnesota ARRA “Self-Assessments” completed by Scott County and the City of Woodbury in late 2011 and early 2012. A copy of the final report, “Energy Code Compliance in Minnesota 2012/2013: Baseline for ARRA Compliance,” is available on Commerce’s website. For further information, contact project manager Bruce Nelson at 651-539-1860.