In March 2012, the International Code Council (ICC) announced the availability of the International Green Construction Code (IgCC), a new model code for constructing and remodeling buildings to a higher sustainability standard. Acting as an overlay to existing model codes, such as International Energy Conservation Code (IECC) and the ICC-700 National Green Building Standard, the IgCC establishes a baseline for energy conservation, water efficiency, site impacts, building waste, material source efficiency and other sustainability measures in new and existing buildings.
As of the time of writing, five states—Florida, Maryland, North Carolina, Oregon and Rhode Island—and a number of cities had adopted the IgCC in whole or part. Maryland, for example, adopted the IgCC to apply to all commercial buildings as well as residential properties taller than three stories. The Rhode Island Green Buildings Act requires all major public facilities be designed and constructed as green buildings and identifies the IgCC and ASHRAE 189.1, another green building standard, as compliance options.
Section 608—which covers building electrical power and lighting systems in new construction and remodeling projects—enhances compliance with the IECC. Most of these enhancements are related to advanced controls.
Interior and exterior lighting that must stay on even when an area is not occupied must be reduced to a step between full power and off to save energy unless it qualifies as an exception. Alternatively, the exterior lighting 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 and parking garages.
All exterior lighting must be reduced or turned off within two hours of conclusion of facility operations.
Exterior facade, sign and landscape lighting, 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 facade and landscape lighting must be turned off from midnight until 6 a.m.
Automatic daylight harvesting controls are required in certain spaces. Plug-load controls also are required. If the building is located in a region where a power provider offers a demand response program, and it does not produce its own on-site 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).
Lighting fixtures that use fuel gas, unless installed in a historic building, must be included in lighting power calculations using a formula converting Btus per hour into a wattage equivalent.
Light pollution is covered in Section 409. First, the building is assigned a lighting zone based on population density; the higher the density, the higher the exterior light level that is acceptable. Next, using the new backlight, uplight and glare outdoor lighting fixture rating system, maximum BUG ratings are assigned per 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.
Low-mercury lamps are required per Section 506, with some exceptions for specialty lamps. Linear bi-pin fluorescent lamps are limited to 5 milligrams (mg) of mercury per lamp; long-life lamps are limited to 8 mg. Pin- and screw-based compact fluorescent lamps are limited to 5–6 mg per lamp, depending on wattage.
An extensive section (808) covers daylighting requirements.
Chapter 9 covers commissioning, and Section 608 includes some additional requirements. First, prior to issuance of certificate of occupancy, a field inspection must verify all lamp, ballast and lighting control installations are in accordance with approved construction documents. The lamps must be reverified after 18–24 months of occupancy. Site lighting must be verified as complying with Section 409. The system installer or commissioning agent must calibrate lighting controls, and they must be recalibrated at 18–24 months. Operations and maintenance documentation for lighting systems, including technical inspections, manuals, fixture relamping and cleaning plan, lamp disposal information, and programmable and automatic controls documentation (including final settings), must be turned over to the owner.
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, lighting power densities that are at least 10 percent lower than in the IECC must be realized.
A green building model code makes sense 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 such as LEED.
For more, visit www.iccsafe.org.