2015 IECC AND IEBC (Base Codes)

Codes And Policy

NBI and several other leading organizations proposed code revisions for a range of I-Codes including the International Energy Conservation Code (IECC) and the International Existing Building Code (IEBC). Proposals focused on the usability and effectiveness of the energy provisions in codes as they relate to new and existing structures.


FINAL STATUS OF THE 2015 IECC: DOE determined that the residential energy code resulted in approximately a 1% savings over the previous version for new construction.  Estimates savings from the existing buildings provisions are not part of the DOE determinations. For more information read NBI’s press release.


Why did energy provisions relating to existing buildings need revision?

Energy use in commercial buildings has not been pursued with the same intensity as energy use in new construction.  As a result, many of the provisions in the existing I-codes (such as the definition of historic buildings) are confusing or inconsistent.  And the scale of energy savings matters.  According to  McKinsey & Company, renovation, maintenance and operation of existing buildings offers over three times the savings from new construction during the period of 2010-2020.


Code changes approved for historic buildings in the 2015 IECC

Historic Building

Any building or structure that is one or more of the following:

  1. Listed, or certified as eligible for listing by the State Historic Preservation Officer or the Keeper of the National Register of Historic Places, in the National Register of Historic Places
  2. Designated as historic under an applicable state or local law; or
  3. Certified as a contributing resource within a National Register listed, state designated, or locally designated historic district.

Commercial Version

C101.4.2 Historic buildings. No provision of this code relating to the construction, repair, alteration, restoration and movement of structures, and change of occupancy shall be mandatory for historic buildings provided a report has been submitted to the code official and signed by a registered design professional, or a representative of the State Historic Preservation Office or the historic preservation authority having jurisdiction, demonstrating that compliance with that provision would threaten, degrade or destroy the historic form, fabric or function of the building.

Residential Version

R101.4.2 Historic buildings. No provision of this code relating to the construction, repair, alteration, restoration and movement of structures, and change of occupancy shall be mandatory for historic buildings provided a report has been submitted to the code official and signed by the owner, a registered design professional, or a representative of the State Historic Preservation Office or the historic preservation authority having jurisdiction, demonstrating that compliance with that provision would threaten, degrade or destroy the historic form, fabric or function of the building.


Code Change Partners

The American Institute of Architects (AIA)

National Trust for Historic Preservation (NTHP)

Natural Resources Defense Council (NRDC)

Institute for Market Transformation (IMT)

ICC Sustainability, Energy & High Performance Building Code Action Committee (SEHPCAC)

Northwest Energy Codes Group