IECC 2009 Overview

Scope of IECC 2009: Section 101 of the Standard describes what buildings and building systems (e.g. lighting) are covered under IECC 2009.  While the IECC 2009 covers both commercial and residential buildings, this summary shall only include the commercial buildings.

Lighting Scope: Section 505.1 of the Standard points out that lighting within certain dwelling units are exempt from this section of the Standard.

Interior Lighting Power Allowance: Section 505.5.2 of the Standard describes the methodology by which a user may calculate how many watts may be used for the interior lighting:

• This method allows the user to look up (in Table 505.5.2 of the Standard) the allowance in watts per sq.ft based on building types (e.g. 'Office'); this allowance is then multiplied by the area of the building type to come up with the interior lighting power allowance.   Additional considerations include:
  • When a building has more than one building type, each building type must comply separately.
  • The standard describes when the user may claim additional allowance, in the case of retail situations, while using display accent lighting.

Exterior Lighting Power Allowance: Section 505.6.2 of the Standard describes a process similar to the method described above.  Individual area types are looked up in Table 505.6.2(2) and the listed allowance is then multiplied by either the square feet (e.g. of a parking lot) or linear feet (e.g. along street frontage) of that area.  Additional considerations include:

• Some area types are tradable in that the user may borrow watts from one area and use them in some other tradable area.
• Some area types are 'nontradable'; the watts in those areas are use-it-or-lose-it.
• Section 505.6.2 contains a list of exterior lighting that exempt from this section.

Installed Interior/Exterior Lighting Power: Section 505.5.1 of the Standard is then used to determine how many watts have been actually installed for the lighting.  Additional considerations include:

• The installed interior lighting power is calculated separate from the exterior.
• In general, the input watts to the luminaire must be used for these calculations, not the lamp watts.
• This section of the Standard contains a list of interior lighting that does not have to be included in this calculation
• The resultant requirement is that:
  • the interior lighting power allowance must be no less than the installed interior lighting power, and
  • the exterior lighting power allowance must be no less than the installed exterior lighting power

Mandatory Provisions:

• Lighting Controls:
  • Space Control: the lighting in each individual space must be separately controlled with a manual control
  • Light Reduction Controls: occupants must be able to reduce the light levels, in a uniform pattern, by at least 50% 
  • Auto Shutoff: the lighting in all buildings over 5,000 sq.ft, with certain exceptions, must be on auto shutoff with occupant override and holiday scheduling
  • Daylight Harvesting: is required per section 505.2.2.3 of the Stnadard
  • Sleeping Unit Controls: section 505.2.3 of this Standard mandates certain controls for all permanently wired lighting and all switched receptacles 
• Tandem Wiring: in certain situations, section 505.3 requires that the ballasts of linear fluorescent luminaires be tandem wired.
• Exit Signs: Section 505.4 sets an upper limit on how watts internally illuminated exit signs may use.
• Exterior Building Grounds Lighting: for exterior lighting not under the control of a motion sensor or exempted under section 505.6.2, Section 505.6.1 sets a minimum efficacy for the lamp(s) being used.