Posted 7/23/2012 12:00 am
Updated 1 year ago
Energy-efficient building techniques that were once considered faddish or experimental have become standard as builders and owners in Arkansas and beyond have realized the long-term savings to be had.
Nationwide, 92 percent of companies said that operational savings influenced their decisions to undertake energy-efficiency projects, according to a recent study by McGraw Hill Construction.
In Arkansas, the desire to improve energy efficiency is showing up in the use of an integrated design approach, building to certifiable standards without necessarily getting the certificate, employing ongoing energy services, retrofitting existing buildings and in the demand for high-performance homes.
"If you start smart ... a green building doesn't have to cost more," said Mary Laurie, sustainable initiatives director at Nabholz Construction Corp. of Conway. "But it takes an integrated team."
Having architects, engineers, contractors and interior designers work together from the start of a project results in a variety of ways to save that don't have additional upfront costs and can vastly improve the energy efficiency of a building. One example: the orientation or siting of a building.
Choosing to elongate a building, orient it in an east-west direction on the property and put most of the glass on the north and south sides, where it doesn't get direct sunlight, uses a method of design called passive solar. This not only takes advantage of natural light, but uses solar energy to retain heat in the winter and reflect it back in the summer, said Clint Whitley, a certified architect and the sustainability coordinator at Cromwell Architects Engineers Inc. of Little Rock.
Even an interior designer's choice of a light paint color to reflect light can help decrease the lighting load on a building and make a difference in the energy required for ventilation because lights throw off heat.
"Sustainability is all about teamwork," Whitley said. "Small decisions on the front end can have huge repercussions throughout the building."
Certifiable but No Certificate
Green building may once have been considered a fad, but with energy efficiency the goal, industry leaders agree that sustainable building practices are here to stay whether they come with a Leadership in Energy & Environmental Design certificate or not.
"It's at the heart of the way we build buildings. We choose sustainable elements whether or not the project is seeking certification," said Bill Hannah, CEO of Nabholz Construction Services of Conway.
As interest in energy efficiency continues to grow, owners are considering life-cycle cost breakdowns and asking for the upgrades they know will save them money in the long run, even though they may cost more upfront.
But, Laurie said, she asks herself, How many people are going to be willing to pay the extra money it takes to get a LEED, Green Globe or one of the many other certifications when they could instead put that money into additional sustainable elements in their building?
Whitley said, "There is additional cost for the management of it [a LEED project], but in general the buildings that we do probably would achieve LEED certification just by default."
Unfortunately, he said, some people treat LEED like a checklist because the process includes a list of points to check off. Ideally, Whitley said, a project should be designed holistically. "What really matters and what is really going to have an impact on this project," he said, should be more relevant than certification.
"LEED has been fantastic in getting the industry to change," Whitley said. "Now, codes are starting to catch up. States are starting to introduce green building codes; even our state is starting to embrace this idea. And as these states, organizations and cities start to adapt these green practices as a norm, I think in a perfect world LEED goes away and it just becomes what we do because it's good design."
Ongoing Energy Services
Some companies that build high-tech, energy-efficient buildings don't necessarily have to keep engineers on staff to maintain their systems and keep them running in tip-top shape. Companies such as Cromwell offer ongoing energy services, monitoring existing building systems and tweaking them for optimum efficiency.
Last year, Heifer International, one of the state's beacons of sustainable building, experienced some reliability and efficiency problems with the 9-year-old systems at its Little Rock headquarter. The nonprofit commissioned Cromwell's energy services department to take a look under the hood and make some adjustments. "It's just like a car: It's going to need a tune-up," Whitley said.
Now, as part of the ongoing energy services, Cromwell's office monitors a computerized "dashboard" with user-friendly graphic displays of information about Heifer's ventilation and hot, chilled and gray water systems.
Other energy services include building simulations and energy modeling, which calculates estimated energy use for different systems, energy audits, building testing for air tightness and indoor air quality as well as thermal imaging to locate where insulation may be lacking.
Retrofitting Existing Buildings
Building a new building isn't the only way to go green. Industry leaders agree that there has been a shift from constructing new green buildings to making energy-efficient improvements in the HVAC systems, insulation, lighting and windows in existing buildings in Arkansas.
Nabholz recently completed a major renovation of the Federal Building at 1111 Main St. in Conway and is pursuing its first LEED certification for the core and shell of an existing building.
"Some interesting aspects of this project: It had asbestos that had to be remediated," Laurie said. "And, get this: It was built in 1969 without a single bit of insulation. We've had to go back in and build onto the insides of the walls to be able to put in insulation. We've also replaced all the single-pane windows with low-e energy-efficient windows." Low-e means low emissivity, which refers to a coating on the glass that helps control the amount heat transferred by sunlight.
Builders can add all the expensive alternative energy systems like geothermal or solar panels they want, but most often in existing buildings, retrofits to heating, ventilation and air-conditioning systems, insulation, lighting and windows are what make sense.
"In heating or cooling, sometimes it doesn't matter what the energy source is; you have to think of all the components together for high efficiency," said Hannah. "It's a combination of all platforms. In and of itself you may not achieve what you want out of an alternative energy system. Overall what you are looking for is efficiency."
Many of the trends in commercial building are making their way to residential building as well. The reason to buy a green home is the same as it is for commercial structures: energy efficiency.
According to a McGraw-Hill Construction study of residential builders, 83 percent said a focus on energy efficiency was what made green homes built today more environmentally friendly than they were two years ago. And green home building has doubled nationwide in just three years from 8 percent in 2008 to 17 percent in 2011.
"There has been a shift away from green for the sake of being green to core principal of energy efficiency," said Keith Wingfield, owner of River Rock Builders in Little Rock.
"People assume from an energy-efficiency standpoint that all new homes are created equal - and nothing could be further from the truth," he said. "My challenge as a builder is to build the most energy-efficient [structures] for the least dollars."
Products alone are not necessarily the answer, he said. However, understanding what they do and not overdoing it can make a difference.
Using a combination of polyurethane spray foam insulation and less costly cellulose insulation is a good example of how to get the most energy efficiency for your money, Wingfield said. Because the polyurethane foam expands and provides a good air seal, using 1 inch of it will work to provide the seal, and to provide the insulating thickness needed he uses the cheaper cellulose.
Keeping insulation at the right depth and ensuring air and moisture barrier joints are taped are low-tech but important practices, Wingfield said. Other methods he employs in the quest for energy efficiency include using infrared cameras to find gaps in insulation and building envelope pressure tests to check for air tightness. Both practices are similar to those offered as part of ongoing energy services for high-tech energy-efficient commercial green buildings.
Wingfield also conducts duct-blast tests to determine the percentage of leakage in a newly installed HVAC system. Some new systems can have 30 percent leakage, which isn't good because the system may never shut off or may require a larger system to compensate for the leaking. There will always be some leakage, he said. But when conducting the duct-blast test, Wingfield said, he looks for less than 10 percent leakage to achieve energy efficiency, though he often can reduce leakage to 5 percent.
Choosing to make $10,000 worth of energy-efficient upgrades can create a high-performance home and the costs will be recouped in energy savings in just a couple of years, he said.
(A roundup of new techniques in sustainable construction.)