It has been just over two years since Indiana adopted its new energy code, the 2010 Indiana Energy Conservation Code (IECC). During that time, a lot of rumors, inaccuracies, and confusion have emerged regarding the application of the code. The following is an attempt to clarify the issue using primary source materials.


In a nutshell:

The 2012 IECC is mandatory statewide for Class 1 structures (commercial buildings and residential buildings with three or more dwelling units). For a definition of “Class 1” structures, see IC 22-12-1-4 of the Indiana Code. The state requires a plan review for all new Class 1 building projects. When applicable, the submittal for a plan review shall include a Compliance Report per the 2010 IECC. When verifying compliance, be careful not to confuse the 2010 IECC with one of the international codes (e.g., 2012 IECC or 2009 IECC).


What ASHRAE 90.1-2007 says:

The 2010 IECC is based on ASHRAE Standard 90.1-2007. Indiana adopted the standard with various amendments as outlined in the Indiana Administrative Code (IAC). As such, we will consider the scope of standard 90.1-2007 along with any applicable Indiana amendments.

Per section 2, subsection 2.1a., the standard provides the minimum energy-efficient requirements for the design and construction of:

  1. New buildings and their systems
  2. New portions of buildings and their systems
  3. New systems and equipment in existing buildings*

*Indiana amendment:

For Indiana projects, please note that 675 IAC 19-4-2 (1) of the Indiana Administrative Code amends the standard by deleting item 3 without substitution.


Section 2, subsection 2.2a., states that the provisions of standard 90.1-2007 apply to the envelope of buildings, provided that the building meets one of the following criteria:

  1. The building is heated by a system with an output capacity that is equal or greater than 3.4 Btu/h sq.ft..
  2. The building is cooled by a system with a sensible output capacity that is equal or greater than 5 Btu/h sq.ft.

Subsection 2.2b. states that the provisions of the standard also apply to the following systems and equipment used in conjunction with buildings:

  1. Heating, ventilating, and air conditioning
  2. Service water heating
  3. Electric power distribution and metering provisions
  4. Electric motors and belt drives
  5. Lighting

Indiana Government Center and the Indianapolis Canal Walk. Image property of Serge Melki.


Exclusions to ASHRAE 90.1-2007:

According to section 2, subsection 2.3, standard 90.1-2007 explicitly does not apply to:

  1. Single-family houses
  2. Multi-family structures of three stories or fewer above grade
  3. Manufactured houses (modular or mobile homes)
  4. Buildings that do not use either electricity or fossil fuel
  5. Equipment / portions of building systems using energy for industrial, manufacturing, or commercial processes.*

*Indiana amendments:

For Indiana projects, please note that 675 IAC 19-4-2 (2) of the Indiana Administrative Code amends the standard by revising the language on multi-family structures of three stories or fewer above grade to instead state, “two-family dwellings”. 675 IAC 19-4-2 (3) amends the language on item 5 from above (which is subsection 2.3c in the standard) to state, “building systems and equipment dedicated to manufacturing processes where operating requirements are primarily intended for the manufactured product or process and not for human comfort.”


Regarding building envelope alterations:

Section 5.1.3 addresses building envelope alterations. It states that all alterations to an existing building envelope shall comply with the standard’s requirements except for when the alterations will not increase the energy use of the building (e.g., adding more insulation to a wall than there was to begin with).

In other words, if a design team replaces old windows with more energy efficient windows, the team should only have to identify the relevant criteria in the specifications or perhaps the cut sheets from the contractor. A comprehensive compliance report (e.g., COMcheck) would not be necessary (or even relevant).


Regarding HVAC systems:

Section 6.1.1 addresses the scope of heating, ventilating, and air conditioning (HVAC) systems. I will not belabor this issue here. In very simplified terms, the standard basically says that new HVAC systems or equipment shall meet the requirements of the standard; however, existing systems and equipment are afforded reasonable exceptions.


What ASHRAE 90.1-2007 does NOT say:

The following administrative issues are nowhere to be found in ASHRAE 90.1-2007:

  1. Exemptions for existing buildings built before a certain date.
  2. Exemptions for historic structures.
  3. Minimal square footages under which the energy code would not apply.
  4. Language addressing additions, alterations, renovations or repairs.


The problem is that ASHRAE 90.1-2007 is a standard, not a code.

Interestingly, the equally stringent 2009 International Energy Conservation Code developed by the International Code Council (ICC) does address many of these administrative items. This underscores the fundamental difference between codes and standards. Codes are written in normative, or mandatory, language with pertinent regulatory and administrative information so that officials can enforce them. Standards often provide “how-to” guidelines that describe current best practices. Standards still tend to be written in normative language because they are often referenced by codes. While they will usually address scope and specific exceptions to certain requirements, standards are typically more technical in nature than codes and can lack enforcement and legislative wording. This is a fundamental shortcoming of adopting a standard as a code.