Frequently Asked Questions (FAQs)

What is considered a residential building?

The term “residential building” includes:

  1. detached one-or-two family dwellings having not more than three stories above grade plane;
  2. buildings that consist of three or more attached townhouse units and have not more than three stories above grade plane;
  3. buildings that are classified in Group R-2, R-3 or R-4 and have not more than three stories above grade plane
What is required for historic buildings?

Note:  The key point is not the age of the building, but whether it is registered or eligible to be registered and listed.  In the following cases, historic buildings are considered exempt from provisions of the energy code (however, we recommend always confirming with the state or local jurisdiction):

  • listed in the State or National Register of Historic Places;
  • designated as a historic property under local or state designation law or survey,
  • certified as a contributing resource with the National Register listed or locally designated historic district; or
  • with an opinion or certification that the property is eligible to be listed on the National or State Registers of Historic Places either individually or as a contributing building to a historic district by the State Historic Preservation Officer or the Keeper of the National Register of Historic Places. 
Can I show compliance using COMcheck if my glazing is over the 40% threshold in the 2009 IECC?

The Scope and Application sections of the 2009 IECC address use of ASHRAE 90.1 (2007) as an alternative.  See below for the text.  It is appropriate to use ASHRAE 90.1 as an alternative when your building exceeds 40% glazing, although it does not guarantee your building will comply.  ASHRAE offers an exception to the 40% limitation that calculates the partial shading provided by permanent opaque projections (Refer to ASHRAE 90.1-2007 Sections and, Exception (b)).

501.1 Scope.  The requirements contained in this chapter are applicable to commercial buildings, or portions of commercial buildings.  These commercial buildings shall meet either the requirements of ASHRAE/IESNA Standard 90.1, Energy Standard for Buildings Except for Low-Rise Residential Buildings, or the requirements contained in this chapter.

 501.2 Application.  The commercial building project shall comply with the requirements in Sections 502 (Building envelope requirements), 503 (Building mechanical systems), 504 (Service water heating) and 505 (Electrical power and lighting systems) in its entirety.  As an alternative the commercial building project shall comply with the requirements of ASHRAE/IESNA 90.1 in its entirety.  Exception:  Buildings conforming to Section 506, provided sections 502.4, 503.2, 504, 505.2, 505.3, 505.4, 505.6 and 505.7 are each satisfied.

How do mixed use buildings need to meet code?

The IECC addresses mixed occupancies by stating that commercial occupancies must comply with the commercial portion of the code and residential occupancies must comply with the residential portion of the code.  

ASHRAE Standard 90.1 addresses high-rise residential and all other commercial buildings.  Residential spaces are those used primarily for living and sleeping and include dwelling units, hotel/motel guest rooms, dormitories, nursing homes, patient rooms in hospitals, lodging houses, fraternity/sorority houses, hostels, prisons, and fire stations.

What are the lighting requirements for residences?

The 2009 IECC requires that a minimum of 50% of the lamps in permanently installed lighting fixtures be high-efficacy lamps (2009 IECC, Section 404.1). The 2012 IECC has increased the minimum percentage from 50% to 75%, along with an exception for low-voltage lighting (2012 IECC, Section R404.1).

REScheck currently does not have a lighting input function; therefore, the lighting requirement should be confirmed under the Requirements Tab in the program.

Where can copies of the energy codes be obtained?
  • Copies of the International Energy Conservation Code (IECC) can be purchased from the International Code Council website.
  • Copies of ASHRAE standards can be purchased from the ASHRAE website.
  • For codes specific to a state or municipality, contact the authority having jurisdiction.