A Step Closer to Net Zero

“I think it’s a good change,” says Lynn Underwood, author of Common Code Problems and The Green Home, from Delmar, part of Cengage Learning, and a building code official with the City of Norfolk, Va., as well as fully certified by ICC, where he sits on four national code development committees. “We have allowed buildings to be built for a long time that are very much energy hogs,” he says. “Basically, this code sets a standard for what modern building practices should be. The 2012 IECC and, eventually, the 2015 IECC will require buildings to use much less energy than they’ve ever used before. This whole cycle is moving in a very progressive direction.”

The energy savings in the 2012 IECC meet or exceed recent national calls from the White House, Congress, the Secretary of Energy, and industry leaders to improve the efficiency of commercial buildings. In addition, it will serve as the baseline standard for the International Green Construction Code (IGCC), currently under development (see Filling the Gap). “This is our first step,” says Eric Makela, engineer and program manager at Pacific Northwest National Laboratory (PNNL), Richland, Wash., working under DOE’s Building Energy Codes Program (BECP), which was funded in 1993 in response to the Energy Policy Act of 1992 and mandated that DOE participate in the model national codes development process, helping states to adopt and implement progressive energy codes. “Our next step will be 50%.”

The changes to 2012 IECC came about as part of a collaborative effort among the New Buildings Institute (NBI), a White Salmon, Wash.-based nonprofit organization working collaboratively with commercial building professionals and the energy industry to promote better energy performance in buildings; The American Institute of Architects (AIA), Washington, D.C.; and the DOE. The organizations submitted a comprehensive proposal, based on NBI’s Core Performance protocol, a direct approach to achieving energy savings in commercial buildings that addresses measures such as cooling, lighting, quality assurance, and renewable energy standards, according to NBI.

In addition, several other key proposals that contribute to the savings were approved independently (see 2012 IECC Primer). “It was truly a collaborative effort among DOE, NBI, and AIA,” says Makela. “But they were certainly not the only parties involved in this process. We had around 27 other contributors who participated in helping us form this proposal.”

Other participants include the International Association of Lighting Designers (IALD), Chicago; Atlanta-based ASHRAE, the organization for heating, ventilation, air-conditioning and refrigeration professionals; and building envelope and window manufacturers. “We were able to get a lot of input from a lot of different parties and gain a consensus on the proposal,” says Makela. “I think what we ended up with were very usable provisions in the code that I think we’re going to get good compliance on.”

The little things

Over the last three to five cycles, much of the energy savings in the revisions to the IECC were achieved through reductions in lighting power densities, according to Jim Edelson, senior project manager at NBI. “You have to install a certain amount of fixtures, and in those fixtures you can only install a certain kind of ballast and lamp, moving from incandescent to fluorescent to more efficient fluorescent and eventually onto LEDs or some other technology,” says Edelson. “That was the main mechanism by which codes have reduced the lighting power usage of buildings.”

In fact, one revision in the base part of the code for 2012 is an option for calculating lighting power densities. The 2009 IECC provides lighting power densities for the whole building. The latest version of the code provides an option for a space-by-space calculation. “There was always a complaint that there wasn’t enough flexibility on a space-by-space approach for calculating lighting power densities,” says Makela. “So we added that into the 2012 IECC. Now there will be two options, which should make a lot of lighting designers happy. They’re getting some flexibility.”

However, lighting power reductions can only take the codes so far. “There are technological limits,” says Edelson. “You have to deliver a certain amount of light. So the most important strategy that needed to move into codes, which has been in voluntary programs for a long time, is control strategies. That’s why there’s a significant change in the lighting control requirements in 2012 IECC because that’s where the bulk of the opportunity is.”

In addition to lighting controls, 2012 also includes additional requirements for daylighting and new requirements for daylighting controls. “Probably the most significant change in 2012 IECC is the extensive use of daylighting and daylighting controls,” says Edelson. “Engineers and designers will see a lot more requirements to make use of available daylight within buildings. That’s where a lot of savings come from — the available daylight.”

For example, the 2012 IECC will require all big-box and warehouse-type stores to have at least 50% of the space in their buildings within a daylight zone (meaning skylights), and they will also have to have daylight controls in those zones.

More extensive use of manual sensors will also be required in the 2012 IECC. “We focused on trying to make sure that what was in 2012 IECC was consistent from a lighting control standpoint to that of what is in ASHRAE 90.1 2007,” says Makela. “We added more types of manual controls to be able to shut off task lights and things like that, which have already been in the standard for at least one, if not two, cycles.”

Additional options include daylighting, automatic lighting shutoff, a lighting control system, and occupancy sensors. “Because of federal mandates for equipment efficiency, we couldn’t touch HVAC equipment efficiency, which was unfortunate,” continues Makela. “So we had to be creative in how we looked at this. We tried to expand the choices.”

For this level of reduction of energy use in commercial building it comes down to these little improvements, says Underwood. “All the things that we’ve taken for granted all these years are really tightened up in the 2012 IECC,” he says. “The changes address these small areas of improvement for each different kind of usage — how commercial buildings are used or maybe even misused. I think the 2012 reflects all that.”

Multiple choice

As building codes require lower levels of energy consumption, more flexibility is needed to reach the goals. To that end, the 2012 IECC contains a section that gives builders great flexibility among three different options, including high-efficiency heating and cooling equipment, a package with lower lighting power densities, or renewable power generation, such as solar photovoltaic (PV), wind, solar thermal, or geothermal (from the heat of the earth, not from a heat pump). Each of these items measures in the 3% to 4% savings range. “We wanted to give a little bit of flexibility on how you got to the 30% reduction,” says Makela. “We tried to make sure they were all fairly equal.”

With the renewable energy option, there was concern about where a device would fit on a high rise, for example. That’s why the code includes the other options. “What this code does for the first time is makes a requirement that every building meet one of three requirements,” says Edelman. “Renewable energy generation isn’t required, but a building has to choose one of these three options, and we expect a certain percentage of them to choose a renewable option.”

Although he’s a proponent of renewable energy, Underwood appreciates the flexibility in this code cycle. “I’m not in favor of mandating that someone has an alternate energy-generating device, although I strongly support it,” he says. “I just don’t think that particular aspect ought to be mandated, but I do think it should be strongly encouraged.”

Keeping track

An entirely new section in the code covers the process of testing and commissioning. “Daylight controls are notorious for high failure, or disconnect, rates, so that’s why we have this commissioning and acceptance testing requirement,” Edelman says. “We want to make sure once those daylight controls are installed, they’re being operated as intended.”

Once controls are installed, they will have to be tested according to a protocol. “You can install all these wonderful automatic controls, but if they’re not set up correctly and don’t function right, we’re not going to get any savings,” Makela says. “That will at least ensure that what is installed will work correctly. We think this is something that has been missing from the code for quite a while.”

However, this protocol may cause problems for building inspectors, according to Underwood. “From the perspective of a building official, requiring a building to be commissioned could present a problem,” says Underwood, who is particularly concerned about the terminology.

In the 2009 IECC, the testing requirement can be fulfilled by a “means” for air balancing and testing prior to issuing a certificate of occupancy. However, the revision requires the actual proof of commissioning once the certificate of occupancy is issued. “Normally, these processes happen after a building is finished and when people are actually using the building — because you don’t know how many people will be in one area or zone until they get in and start using it,” explains Underwood. “The 2009 code lets us do a certificate of occupancy, as long as there’s a method of performing the process. However, in the 2012 IECC, it says that we can issue a certificate of occupancy before the commissioning, which then has to happen within 90 days. Building officials are going to go back within the 90-day period to establish the building’s been commissioned. This could be problematic across the country, if people don’t give the commissioned results to the building official in that period of time.”

Despite this potential problem with commissioning, the process will help buildings achieve a reduction in energy use and may also be used for compliance reporting after building occupancy. Computer modeling of the 2012 IECC shows more than 30% better energy efficiency, on average, than the ASHRAE 90.1-2004 model code. Yet, actual performance of the buildings once they’re built and occupied may be more difficult to determine. The funding for the U.S. government’s program, the U.S. Commercial Building Energy Consumption (CBEC) Survey, is currently suspended.

“The performance of buildings is one of the major issues nationally,” says Edelson, who cites that NBI appreciates all independent efforts to collect data. “Going forward, we encourage programs, such as U.S. Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED) effort, to collect more information and document their buildings’ performance.”

Still, even private collection of that information remains scarce. “It’s kind of spotty information at this point in time,” says Makela. “I haven’t heard of any plans in my department to start doing that, even though it would be a really great piece of information to have. You can always do computer simulations to project energy usage, but until you actually hook up the meters and really start looking at what the building’s doing, you’re not sure how accurate your models are. A measure of actual energy is going to be a lot more viable in the future.”

Adoption issues

When adopting their own energy codes, states typically adopt the full-published IECC or develop a state-specific amended code. “Jurisdictions and adoptions vary across the country based on how the state government or the state constitution is organized,” explains Underwood. “Some states are called Dillon’s rule states, and some states are home rule states.”

For example, Virginia, a Dillon’s rule state, works from a state-adopted code and every city, county, and town has to enforce exactly that code. However, New Mexico or Arizona, both home rule states, may adopt a state building code, but its cities may adopt their own code. “The City of Phoenix has had the Phoenix code since about 1930,” notes Underwood.

Currently, 45 states, Washington, D.C., and the U.S. Virgin Islands use an edition of the IECC (Map)(click here to see Map.). Only about 25 of those states currently follow the 2009 IECC, the most recently published edition. “We see the effort in various forms,” says Edelson, who explains that the leading states, such as Massachusetts, have already adopted a very similar code as their “stretch” code, whereas other states like California, for example, already have a code with similar energy savings goals, but in a different format, such as Title 24. “They’ve developed their own independent code, so they won’t be adopting IECC.”

DOE is not only mandated to work with ASHRAE on Standard 90.1 and the IECC on their code, but also to help states adopt and implement new codes. The American Recovery and Reinvestment Act of 2009 provided a new goal for DOE’s building codes efforts — 90% compliance with energy code requirements for each state.

“Our marching orders from the BECP is to promote the adoption of the 2009 IECC and ASHRAE 90.1 2007, so we are pushing hard to get states to adopt those,” says Makela. “After the push to adopt 2009 IECC, we’ll be looking at states to adopt the 2012 IECC. ”

SIDEBAR: Filling the Gap

The gap between existing construction codes and green rating systems will soon be filled, according to the International Code Council (ICC). Programs, including the U.S. Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED), were not designed to act as regulations. Therefore, in 2009, ICC launched the development of the International Green Construction Code (IGCC), “Safe and Sustainable: By the Book,” committed to developing a model code focused on new and existing commercial buildings addressing green building design and performance.

The IGCC references ANSI/ASHRAE/USGBC/IES Standard 189.1-2009, “Design of High-Performance Green Buildings, Except Low-Rise Residential Buildings,” as an alternative compliance option. The code addresses residential construction by referencing ICC 700-2008, “National Green Building Standard,” developed by the National Association of Home Builders and the ICC.

More than 2,000 organizations and individuals, including hundreds of green building experts, have integrated their work into a usable, enforceable document, addressing every type of building in a manner that is flexible enough to meet the needs of diverse jurisdictions. IGCC sponsors include: The American Institute of Architects (AIA); ASTM International; the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE); USGBC; and the Illuminating Engineering Society (IES).

IGCC follows ICC’s development process. Public Version 2.0, which was published on Nov. 3, 2010, is available from the ICC website at http://www.iccsafe.org/cs/IGCC/Pages/IGCCDownloadV2.aspx. The issue date deadline is early 2012. These documents are available as adoptable language or as resource tools in the development or revision of green regulations at all jurisdictional levels, and are designed to integrate with existing I-Codes to create a new regulatory baseline for green construction.

SIDEBAR: 2012 IECC Primer

The 2012 IECC contains many important, first-ever technical features. In addition, changes were made to the 2012 IECC to make the code more consistent with the International Residential Code (IRC), also published by the International Code Council. Several modifications were also made to make the IECC more consistent with ASHRAE 90.1. Therefore, the 2012 IECC will contain two distinct, separate, and comprehensive sections of energy provisions for commercial buildings and low-rise residential buildings, each with their own transformations.

Four key areas of improvement to the residential section of 2012 IECC include:

• Reduced leakage in duct systems and building envelopes, verified by testing. The proposal requires that all ductwork be inside conditioned space, sets new leakage limits on the ductwork, and adds a new requirement for testing the air tightness of the building envelope. As an alternative, homes with high-efficiency HVAC equipment are exempted from the requirement for ducts inside the conditioned space and are subject to less stringent duct and whole-house testing requirements.
• Improved envelope insulation. Fenestration U-factors (including skylights) are reduced in most zones. Wood-frame wall insulation is increased from R-13 to R-20 in zone 4, and ceiling insulation levels are increased on zones 3 and 5.
• New provisions to limit energy loss from domestic hot water pipes. The IECC and IRC currently have minimal requirements for energy efficiency related to water heating. This proposed pipe insulation requirement represents a modest initial investment that will save energy for the life of the home, even through water heating equipment change-outs. The proposed requirements are structured to encourage “short and skinny” pipe runs that will minimize energy losses due to stranded water in pipes. Hot water pipes that are longer and/or larger in diameter will require insulation.
• Larger fraction of high-efficacy lighting. The proposal increases the fraction of lamps that must be high efficacy from 50% to 75%, a reasonable improvement given the advances in efficient lighting and the approaching federal standards that will require efficient lighting by 2014.

Additional minor changes include the definition of continuous insulation; elimination of the high-efficiency equipment option to avoid issues of federal appliance standards preemptions; and clarifications to exemptions involving blower door and duct leakage testing.

The latest edition of the IECC includes six key changes to commercial building requirements:

• Building envelope. Changes include continuous air barriers, significant improvements in most

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  glazing, and enhancements to opaque envelope performance.
• Mechanical systems. Improvements include sections regarding economizers, more use of demand controlled ventilation, and additional calculation procedures for determining loads and equipment sizing.
• Quality assurance. This section incorporates requirements for testing and commissioning of mechanical systems and performance testing of daylight-related controls.
• Lighting controls. Reduces energy needed for lighting based on more efficient illuminating equipment and the use of several lighting control strategies.
• Daylighting and controls. Includes additional availability of toplight sources when combined with automatic daylight controls and comprehensive control strategy for all daylit zones.
• Section 506. Contains three approximately equivalent packages to add to the savings in this proposal. These three options are focused on efficient HVAC equipment, reduced lighting power density plus automatic daylight controls, or on-site renewable energy generation. As energy codes move to higher efficiency levels with new types of strategies, building flexibility into prescriptive codes will offer additional pathways to support market adoption and compliance.

Other minor changes include those addressing: cool roofs; skylight curbs; window-to-wall ratio requirements; options for meeting continuous air-barrier requirements and fenestration leakage rate testing; lighting power densities and lighting controls; minimum equipment size thresholds; and low-sloped roofs.

Source: U.S. Department of Energy