IECC 2009 contains a number of changes impacting lighting for commercial buildings, including:
• Forced choice of compliance with entirety of IECC or 90.1
• Required circuiting for independent control of lighting in “daylight zones”
• Revision of additional retail display allowances
• Added exemptions to interior lighting wattage that must be counted for compliance
• Splitting the exterior power allowance using a system of outdoor lighting zones
• Clarifications and practical application language changes