The IgCC establishes a baseline for new and existing construction regarding energy efficiency, water efficiency, site impacts, building waste, material source efficiency and other sustainability measures, acting as an overlay to existing model codes such as the International Energy Conservation Code (IECC) and the ICC-700 National Green Building Standard.
A green building model code is sensible when one considers governments around the country are requiring a LEED rating for public construction. The IgCC provides a series of sustainability requirements in code language that is adoptable, usable and enforceable, and references ASHRAE 189.1 as an alternate compliance option. It is intended to complement rating systems like LEED. As of the time of writing, Florida, Maryland, North Carolina, Oregon and Rhode Island and a number of cities have adopted the IgCC in whole or in part.
What’s in it for lighting? How is the IgCC different than the IECC?
Electrical power and lighting systems in new construction and remodeling projects is covered in Section 608. The lighting aspects enhance compliance with the IECC. Most of these aspects are related to lighting controls.
Indoor and outdoor lighting systems that must remain operational even when the lighted area is unoccupied must be reduced to a step between full power and OFF to save energy during these unoccupied periods unless the application is specifically exempted. Alternately, outdoor lighting systems can be controlled by occupancy sensors or be self-powered (solar). Applications include corridors, enclosed stairwells, storage and stack areas not open to the public, parking garages, and all outdoor lighting within two hours of conclusion of facility operations.
Exterior façade, sign and landscape lighting, meanwhile, must be automatically turned OFF within one hour of facility operations stopping up until one hour of operations resuming. If facility operation is continuous, decorative building façade and landscape lighting must be turned off from midnight to 6:00 AM.
Automatic daylight harvesting controls and plug load controls are required in certain spaces. If the building is located in a region where a power provider offers a demand response program, and it does not produce its own onsite renewable energy to satisfy 20 percent or more of its electrical demand, then lighting in certain office spaces must be capable of reducing the total connected lighting load by at least 15 percent, with some exceptions (Section 604).
Light fixtures that use fuel gas, unless installed in a must be included in lighting power calculations using a formula converting BTU/hour into a wattage equivalent.
Section 409 covers “light pollution,” imposing a maximum outdoor system light level based on lighting zone, in turn based on population density; the higher the density, the higher the outdoor light level that is acceptable. Additionally, maximum backlight, uplight and glare ratings for outdoor light fixtures are assigned for each outdoor lighting zone.
The building must be metered (with individual metering per tenant in tenant-occupied buildings), per Section 603. The information must be collected and reported, with a category for interior and exterior lighting used in occupant spaces and common areas.
Section 506 requires low-mercury lamps, with some specialty lamps being exempted. Linear bi-pin fluorescent lamps are limited to 5mg of mercury per lamp; long-life lamps are limited to 8mg. Pin- and screw-based compact fluorescent lamps are limited to 5-6mg per lamp depending on wattage.
Section 808 presents extensive requirements for daylighting.
Chapter 9 covers commissioning, with additional requirements in Section 608. Before the certificate of occupancy is issued, a field inspection must be conducted to verify that all lamps, ballasts and lighting controls are installed in accordance with approved construction documents. The lamps must be re-verified at 18-24 months of post occupancy. Site lighting must be verified as complying with Section 409. Lighting controls must be calibrated by the system installer or commissioning agent, and re-calibrated at 18-24 months. Operations and maintenance documentation must be turned over to the owner for all lighting systems, including technical inspections, manuals, fixture relamping and cleaning plan, lamp disposal information, and programmable and automatic controls documentation (including final settings).
Chapter 10 covers existing buildings. The current language of the code as of the time of writing required daylight harvesting controls in daylight zones. Additionally, exterior lighting shutoff must use either a time switch or a combination of a photosensor and a time switch.
Appendix A provides a list of advanced electives that jurisdictions can implement for more aggressive levels of sustainability. For example, in one option available to jurisdictions, lighting power densities must be realized that are at least 10 percent lower than in the IECC.