Ramifications of the 2012 International Energy Conservation Code

Senate Bill 3724, signed by Governor Quinn on August 17, 2012, amended the State of Illinois’ effective date for the 2012 International Energy Conservation Code to January 1, 2013. The 2009 IECC remained in effect until January 1, 2013. This new legislation modifies the home rule clause utilized by cities with a population over one million, now mandating that they cannot use the clause to adopt any energy code that does not meet the 2012 IECC adopted by the State.
The City of Chicago is expected to adopt the new code in early 2013. Per the code, additions, alterations, renovations or repairs to an existing building shall conform to the new provisions; however the unaltered portions of the building are not required to comply. Below, we have broken down some of the changes found in the 2012 IECC, and a few things that remain the same as under the previous 2009 IECC.
What Has Changed:
• The stringency of requirements for each climate zone has increased. The increase to building envelope thermal requirements varies by component. Some of the most notable increases are as follows:
o Roof insulation R-value has increased to 49 from 38.
o Window performance has increased by 20 to 25 percent.
o All wall assemblies of metal stud construction are required to have continuous insulation, outside of the stud cavity
• Commissioning of mechanical systems and lighting controls is required for all commercial buildings.
• All residential projects must pass an air leakage test of the building envelope, commonly referred to as a blower door test. The criteria for climate zone 5 are 3 air changes per hour at 50 Pascals of pressure.
• Enclosed rooms require occupancy sensors.
• In office settings, lighting power densities are reduced to 0.9 watts/square foot.
• Daylighting control zones are required within 15 feet of windows for open office spaces and large enclosed spaces located along the building exterior.
• Demand Control Ventilation (DCV) is required for spaces larger than 500 square feet and with occupant loads greater than 25 people / 1000 SF.
• Mechanical systems and lighting controls must undergo commissioning.
• Registered Design Professionals must provide proof of commissioning for mechanical systems and functional testing of automatic lighting systems—including a commissioning plan and draft commissioning report—to receive a Certificate of Occupancy.
• Construction documents must indicate commissioning requirements.
What Has Not Changed:
• As in the 2009 IECC, the 2012 IECC contains separate provisions for low-rise residential buildings (3 stories or less) and commercial buildings, which includes multifamily residential buildings taller than 3 stories.
• Historic buildings or structures, of all building types, are exempt from the requirements of this code
• Residential projects can achieve compliance through meeting prescriptive requirements described by the code in building thermal envelope, mechanical and electrical systems, or through simulated energy performance analysis, typically achieve by computer modeling.
• In addition to the prescriptive requirements outlined for commercial buildings, the IECC also includes its own performance based energy modeling path to compliance.
• Commercial projects can achieve compliance through the requirements set forth by the IECC or through ASHRAE 90.1-2010.