Over the last decade, the green building movement has dramatically transformed the building sector in the United States by introducing more sustainable products and techniques while continuously raising the bar on building energy efficiency. Today, that bar is officially recognized by the industry at large with the International Green Construction Code (IgCC). Released this past March, the IgCC is the nation’s first official model green building code.
“The IgCC is certainly a win for advancing green building and represents a big step beyond programs like Energy Star, LEED, and Green Globes,” says Sean Denniston of New Buildings Institute (NBI), a nonprofit group committed to improving commercial building energy performance. “These programs helped pave the way by introducing new and sustainable practices. But standardizing these practices, as the IgCC does, gives jurisdictions a model to work from when pursuing policies that improve building performance and reduce the environmental impact of buildings.”
Along with several industry partners, NBI participated in crafting aspects of the IgCC related to energy. As an overlay code among the International Code Council’s (ICC) suite of I-codes, the IgCC set a goal of 10% better energy efficiency than the 2012 International Energy Conservation Code (IECC). That goal, experts agree, was achieved. While 10% may seem somewhat nominal for energy efficiency in a green code, the 2012 IECC, which serves as the basis for the IgCC, is roughly 25% better than the 2006 version that many jurisdictions follow today.
In all, cities and states that adopt the IgCC will require commercial buildings to be up to 40% more efficient than most currently used standards. Already though, a number of progressive states and municipalities have begun implementing the IgCC’s provisions for commercial buildings, having done so even before the final version was approved.
“The IgCC is by no means a one size fits all code,” says Denniston. “As an overlay code, it is meant to work in conjunction with a jurisdiction’s existing codes and therefore, as a whole, will be appropriate and unique to individual geographic locales. Still, the IgCC, wherever adopted, will provide the consistency of certain guidelines for green building measures, including those that address energy efficiency.”
Metering A Building’s Performance
Indeed, much of the IgCC is expressly focused on improving building performance, not just in theory but in actual measured fact, with its innovative metering solutions and requirement of meter installation for all fuel types, including on-site renewable energy sources.
In addition to more basic conditions for the installation of whole building meters, the code includes a two layered approach to sub-metering for HVAC, lighting, plug, process, and building operation loads. Unlike other efforts to codify metering and sub-metering, this approach maximizes the benefit of the data gathered while minimizing the effort required in design and construction.
“And, metering systems must be able to be remotely monitored so that facility managers (fms) can view all meters from a single workstation,” says Roger Rotundo, general inspection supervisor for the City of Phoenix, which has already adopted the IgCC. “This will give them a great idea of where exactly the energy is being used.”
Another pertinent provision of the IgCC is the Zero Energy Performance Index (zEPI) which establishes a new standard energy usage metric based on the average performance of the building stock at the turn of the millennium. The idea is simply to fix a reference point that will help inform progress.
“For the last 30 years, each new code has been measured against its immediate predecessor, so a constantly moving baseline makes gauging progress in energy codes very difficult. This renders the percentage gains for individual buildings largely meaningless,” explains Denniston.
With the zEPI scale, in order to meet performance targets, fms will be required to act in some way as a member of the design team to ensure that the intentions for a building are realized when occupied and operated or adjustments are made as needed.
Other Gains For Efficiency
There are several other provisions that provide opportunities for enhanced efficiency in the IgCC:
Daylighting. A concept that has gained many advocates in recent years, daylighting, which relies heavily on the use of natural light to reduce energy consumption, is an important facet of the IgCC. Many whole classes of buildings are required under the code to be designed so at least 25% of the regularly occupied square footage is in a daylighting zone with automatic controls.
Regarding these controls, building operators and fms will be tasked with ensuring this equipment is not obstructed. They should also be instructed on how to monitor the systems, adjust sensitivity, and override controls when necessary.
“But once it’s in place, we have found that the automation for our daylighting systems are working wonderfully,” says Rotundo.
Energy Star. The requirement that most equipment installed as building components be Energy Star rated is yet another significant aspect of the IgCC. Fms are required to keep a list of installed, portable, Energy Star-eligible appliances and equipment, indicating whether they qualified.
Energy reduction for heating and moving water. Another energy saving measure under the code is its requirement for shorter pipe runs, smaller pipe diameters, better pipe insulation, and more efficient fixtures, which is intended to reduce consumption and improve heating efficiency of water. Also, heat recovery from high use applications and improved water heaters promise to reduce energy used by hot water systems. Fms can expect these mandates to result in significantly reduced water consumption rates and lower water and sewer bills.
“This is a huge plus, especially for Phoenix,” says Rotundo. “We’re seeing the [water] distribution itself changing so that it doesn’t contain a lot of unnecessary water, and the hot water gets to where it needs to go much quicker; this means there is less need to run it for long periods.”
Commissioning. The IgCC also includes measures aimed at ensuring a building is constructed as it should be. As opposed to the 2012 IECC, which only requires commissioning of HVAC systems and lighting controls, the IgCC requires commissioning for the envelope and lighting systems in general, in addition to a whole range of non-energy systems now needing some level of testing documentation.
“As a municipality, commissioning is one of the most vital components of the code,” explains Rotundo. “To have the additional evaluation and the additional expertise that we may not possess in looking at the efficacy of each system, that’s extremely important.”
Renewable energy. With the idea that renewable energy is likely to play a growing role in the future of building operations, the IgCC also includes a requirement that buildings produce enough renewable energy on-site to provide 2% of the annual energy usage. But, because not all buildings are physically capable of providing that level of production, the code includes allowances for Renewable Energy Credits, which refers to the purchase of the environmental benefit of off-site renewable energy consumption, as a means for meeting the requirement.
Looking Towards The Future
These and many other components of the code represent a remarkable achievement in green building—the industry wide arrival of a new era in sustainability that will, no doubt, continue to evolve. While the IgCC is a true step forward, it also offers a glimpse beyond its current iteration and into the future.
Like the IECC, the IgCC will be updated every three years. Many experts agree that future versions are likely to include what is known as outcome based compliance paths, which measure actual energy usage as opposed to predicting consumption through model based prescriptions.
The concept had been vetted for inclusion into the current IgCC by a broad coalition of organizations representing the design, fm, and building owner communities—BOMA International, The American Institute of Architects (AIA), NBI, and the National Trust for Historic Preservation are just a few of the members of the review coalition. And while the proposal did not make it into the final version of the model green code, progressive jurisdictions may still adopt an alternative outcome based compliance path along with the IgCC.
“With today’s technologies and design practices, we know that extremely high energy performance in buildings is achievable,” says Jessyca Henderson of the AIA. “We also know that prescriptive energy codes will only get buildings so far in terms of efficiency. The largest gains in energy savings will come from setting performance targets for buildings and allowing the design team in partnership with the owners and fms to meet them,” Henderson explains.
While code language and enforcement mechanisms focus on a building’s physical characteristics, a significant portion of its energy use is still determined by operational characteristics and occupant behavior—factors with which fms are often most familiar.
As it is, prescriptive code structures only regulate physical features of the building which can be addressed during the design and construction process. This represents an increasingly significant limitation to the ability of current energy codes to affect building energy use, especially at the aggressive performance targets being set for codes. Increasingly, these codes will need to address post-construction energy loads.
In the meantime, Denniston suggests that many of the IgCC’s existing provisions, especially those related to metering specifications and performance targets, indicate the trend towards a more comprehensive, measured approach towards overall building performance based on actual outcomes. And although outcome based compliance did not make it into the IgCC, some of the accepted provisions will make for a solid foundation for its inclusion in the future.