In the United States, residential and commercial buildings account for approximately 41 percent of all energy consumption and 72 percent of electricity usage, according to the U.S. Energy Information Administration’s Electric Power Annual. Buildings can increase their energy efficiency through the use of energy efficiency standards, which set minimum efficiency requirements for new and renovated buildings. The adaptation and enforcement of building energy codes and standards are wide reaching, helping to lessen the impact of energy, economic and environmental challenges.
According to Architecture 2030, 75 percent of the buildings in the U.S. will be new or renovated by 2035. Since most of a building’s operation and environmental impact is determined by decisions made prior to its construction, energy efficiency standards provide an opportunity to assure savings through design, technology and construction practices. Those cost savings are beneficial to both the building owner and tenants. For the building owner, “if you improve the energy performance of your building, you can reduce your monthly utility costs, and also reduce any cost for the initial capital expenditure for equipment,” says Dave Evers, vice president of research and development at Butler Manufacturing, Kansas City, Mo.
However, as Bob Zabcik, director, research and development at NCI Building Systems, Houston, notes, many times it is not the building owner who is paying the bills. Since the building’s energy efficiency may not be as important to the building owner as its tenants, as in lease space, compliance is one way to ensure the important changes are done that will continue to improve the energy efficiency of the nation’s buildings.
Up until the release of the 2006 International Energy Conservation Code (IECC), there wasn’t a whole lot of change in building codes. However, in recent years, “the level of stringency has increased, and it’s increased quickly,” Evers notes. “Up through 2006, not much changed. And then in 2009, there was a pretty big jump. And then in 2012, there was an even bigger jump in the stringency requirements. So quite rapidly, it’s changed.”
The newer standards are more complex and more stringent than ever before, requiring contractors to change the way they’ve done things in the past. The listed and prescriptive assemblies are more complex and in some cases, more difficult to install. For example, “insulating the building envelope, for a lot of contractors, up until the last five years, hasn’t changed much, and now suddenly, it’s changed,” Evers says. “So they have to get used to the idea that they can’t keep doing what they’ve been doing.”
Another problem is that some local code officials do not fully understand the changes to the energy codes themselves, leading to spotty or inconsistent enforcement. “There’s a tremendous amount of misunderstanding from building officials to architects to owner and builder, all the way around the loop,” notes Zabcik. While people may understand what the energy code is trying to do, there’s a lot of misunderstanding in how it works, and how to get to the end goal. “That’s easily the biggest challenge that the industry faces,” he adds. “A tremendous amount of education needs to happen, and there’s a fair amount of reluctance in the marketplace to learn it.”
Education and Training
Educating contractors is the best way to avoid any confusion with the more complex energy codes. “Don’t try to paint with a broad brush, and don’t try to take short cuts, or just simply look at R values and think bigger is better,” Zabcik recommends. “This is quite often not the case. Different systems and constructions in the code are evaluated differently, and different parts of the country are evaluated differently.”
“A lot of the approaches that the code offers are oversimplified to the point that they are specifying unbuildable assemblies for certain buildings,” Zabcik explains. When questions arise, the important thing is to call the manufacturer, or insulation supplier, and find out what they offer that meets the same performance level of the assembly that’s being described in the R-factor tables. “You don’t have to, nor really in a lot of cases should you, try to match the prescribed assembly itself. Instead, you’re trying to match the performance of the prescribed assembly. That’s the idea of the U-factor compliance path, and that doesn’t even get into envelope trade-offs, which are really critical to get complete flexibility-you’ve got to have this in order to design the system that you need to be designing.”
Butler holds webinars and training sessions to educate the building contractors on the changes, and not only the changes, Evers says, but what options they have to comply. “A lot of contractors are used to just going through the check box, or the prescriptive code requirements, and that’s one way of doing it, but there are a variety of ways,” he says. “For instance, if you have tested assemblies, different insulation assemblies, you can use those.” Evers adds that there is a government program called COMcheck that helps with compliance, while providing some trade-offs for different assemblies, allowing buildings to be fine-tuned.
For NCI, Zabcik notes, “the biggest thing is training ourselves and preparing ourselves to be the experts.” Zabcik adds that he readily makes himself available to customers, architects and building owners to talk them through some of the energy code processes. They’ve also trained an internal staff of energy code experts at each of the company’s brands to do site-based management, helping out at the builder level. “Every business unit of ours operates little differently, and they have different market positions, so they want to attack problems a little differently,” he explains. “So we’ve trained our internal staff to do some sitebased management to get some of that education across to the builders.”
A Need to Innovate
The biggest opportunity, Zabcik says, is that energy code compliance displays a great need to innovate. From innovating both the products and the approaches, the opportunity lies in creating new systems that perform better at a lower cost.
One way to do that is by going to a whole systems construction. “The metal building companies all control not only structural steel, but the exterior roof and walls, the cladding systems, daylighting systems, etc.,” says Evers. “It’s not like in the conventional world, where the designer picks and chooses and makes up their own assemblies on a per-project basis. The metal building manufacturers can now actually integrate the system with the structural, panels, insulation, daylighting, and so on, as a complete package, which they can replicate. By being able to use the system on more than one project, they can also afford to make investments in the products and in the development and testing of those products, so that it becomes cost-justified for the manufacturer.”
At Butler, they’ve invested in testing assemblies to provide contractors with a good line of options for different assemblies at different levels of performance. “In some cases, contractors can actually achieve higher levels of performance at less cost than the pre-defined, or prescriptive, assemblies that are in the code,” Evers explains.
With Butler’s IAS-accredited Guarded Hot Box test, roof and wall assemblies are replicated to test the actual heat flow through the system, giving contractors a better handle on the building envelope performance. Another tool that Butler offers to Butler Builder dealers is its E-Valuate tool that provides a variety of roof- and wall-assembly options based upon a building’s location, local utility costs, and construction costs to see which system offers the best payback and benefits.
The 2015 IECC is just around the corner, and for Evers, it appears there might be a chance for things to level out a bit. “I think the opportunity there is to get the state and local code officials to better understand and more uniformly enforce the recent changes, as opposed to continuing down the path of stringency,” he says. It’s also an opportunity to take a look at some other features, such as daylighting and air infiltration, equipment efficiencies and lighting systems, and see what else can be done to increase a building’s energy efficiency.
Zabcik believes that one thing we will be seeing more of in the future is envelope conditioning, which takes a look at how the building envelope is performing even before the interior finishes are done. By having a testing agency do tests for air and water infiltration, possibly with infrared thermography, it’s possible to ensure that the building is performing the way that it is supposed even before it’s completed.
He also believes that within four or five years, it may be required to energy model a building just to get a building permit. “As the building codes get more complex and stringent and tools get easier to use, energy modeling is going to become a more attractive option to show compliance.” Along those lines, Zabcik also believes that more attention will be paid to condensation modeling and moisture remediation to reduce latent loads and help ensure long-term performance.
“Energy modeling really frees the hand of the designer,” Zabcik says, “because it’s a true performance- based metric to show code compliance. It frees the hand of the designer because it doesn’t have a lot of requirements on how the designer is going to get there. It just sets a performance level that the building has to have. And whatever methodologies the designer wants to employ to get there, it’s up to him. And that’s really how any code should work.”