Energy-Efficient Strategies Help Property Owners Save Money and the Environment.
Energy efficiency may be earth-friendly but it also offers bottom-line savings and a competitive edge.
For example, the 73,000-square-foot Ridgehaven building, headquarters for the San Diego Environmental Services Department, realized an annual energy savings of $80,000 a year after an environmental renovation. The 48-story, 1.6-million-sf office tower at 4 Times Square in New York cut energy use and greenhouse gas emissions by 40 percent after its energy-smart redesign. Non-polluting fuel cells and rooftop solar panels have contributed to the property's annual energy savings of $500,000, which is expected to pay for the efficiency measures within five years.
In addition, a number of cutting-edge real estate investment trusts “see a competitive advantage at being able to offer a lower square-footage charge on the basis of having lower operations and maintenance charges,” thanks to energy conservation, says Joseph Romm, founder and executive director of the Center for Energy and Climate Solutions in Annandale, Va.
The process of making buildings more energy efficient is easier and often less expensive than it used to be, but it requires forethought and planning. At its simplest, applying basic common sense to retrofits and building maintenance can provide substantial energy cost savings. Designing and constructing an energy-efficient building from the ground up is more complicated. Yet in both cases, energy costs are reduced and resale value is enhanced. “It may take several years, but eventually, inefficient buildings will really be looked down upon, and they'll just be increasingly unattractive,” Romm says.
Setting the Stage
Energy efficiency often starts at the site selection stage. “The shape and orientation of the building already establishes up to 40 percent of the energy consumption,” Romm says.
“For new buildings, the most important thing you can do is make use of whatever nature has to offer,” says Huston Eubank, senior consultant and research associate with Green Development Services at the Rocky Mountain Institute in Snowmass, Colo. “And the most important of those is daylight. Electric lighting puts a lot of heat energy into a building — no matter how efficient it is — and that's energy that has to be removed by air conditioning,” he explains.
Builders should consider many elements when positioning a building on its site. “One of my pet peeves is that I see so many big glass office buildings, and the designers and owners apparently don't notice there's a difference between north, south, east, and west,” says Craig A. Melby, CCIM, president of ITRA Palm Beach in Stuart, Fla.
A building's north side poses few problems; it's shaded and there's no glare, Melby points out. Proper landscaping on the south side can shield a low building from summer sun rays and let it receive passive heat in the winter when the sun is low and the trees are bare, he says.
The east and west sides are more challenging. “On the east side, the day is still cool when the sun starts coming in, but then your building starts heating up and there's nothing you can do about that,” he says. “It's low on the horizon, and all the shading in the world won't help that unless you put in special windows and special blinds.” This can be done, but it is more cost- effective to position the building so it faces a different direction, he adds.
“The west side of the building is worst of all — you get a hot afternoon, and the setting sun just comes blasting through the windows. So instead of putting windows over there, that would be a good place to minimize the windows and put in your stairwells or your services or your parking structures.”
These decisions, when made in the planning stages, “don't cost any extra money and make the building much more energy efficient and much more pleasant to work in,” he says.
Melby practices what he preaches; he's currently building a mountain rental lodge using insulated concrete forms that have an R-50 insulation value. The lodge will employ passive solar heating techniques as well: Most of the windows are on the south side of the building and are shaded to cut the heat in the summer and allow sun in the winter.
“The spectacular view is east,” he says, “so everyone urged me to put big picture windows there. But in the summer, I'll have so much heat pouring through those windows, the lodge will heat up, and in the winter, I'll lose so much, it'll be cold. So I did put in some windows — small and well placed — so I do see some of that view, and I put my porch on the east side. But not the big picture windows.”
Shedding New Light
Lighting is an essential element in energy conservation, primarily because it also affects heating and air conditioning use. “A lot of lighting design is a remnant of a time — even just 20 years ago — when most office workers wrote on unilluminated horizontal surfaces rather than illuminated vertical surfaces,” Romm says. The incorporation of computer terminals into the everyday office means workers are dealing with much more glare. “That glare represents wasted energy, and it undermines productivity,” he says.
Today's lighting fixtures are much more efficient, even more so than those that are just 3 or 4 years old, he says. “And there's better lighting controls that allow rooms not only to go dim when people aren't in them, but for them to dim when it's sunnier.” A costlier solution but one that improves worker productivity is to give workers direct control of their light levels.
To increase energy savings, Romm recommends reducing the number of existing fixtures; replacing 4-foot fluorescent lighting fixtures with more-efficient lamps, control ballasts, and optical reflectors; replacing incandescent bulbs with compact fluorescents; and installing sensors to turn off lights in vacant rooms and photocells to adjust light to changing outdoor conditions.
The U.S. Department of Energy followed this strategy in 1993 in its Washington, D.C., headquarters and reduced lighting electricity use by 60 percent, he reports. The DOE saved about $400,000 a year and reported more employee satisfaction with the upgrade as well.
“A three-year payback, typical in lighting retrofits, is equal to an internal return rate in excess of 30 percent,” according to Greening the Building and the Bottom Line: Increasing Productivity Through Energy-Efficient Design, an RMI publication.
Lighting maintenance could save commercial building owners $20 billion a year, as well as lead to improved productivity and enhanced safety, according to Cary S. Mendelsohn, chairman of the National Lighting Bureau in Silver Spring, Md. Better maintenance could cut 10 percent to 20 percent of the 1 trillion kilowatt hours of electricity used by nonresidential sources every year. The waste includes light that's absorbed by dirt and dust, old bulbs and tubes no longer working to their capacity, and extra lighting capacity where it's not needed, he says.
Here Comes the Sun
In addition to using efficient fixtures, building owners can increase natural light by using skylights and lightshelves — exterior and interior fittings that reflect and redirect light.
“Good daylighting requires very careful thought,” Eubank says. “The trick is to get the light onto surfaces in the room. You don't want to light people; you want to light the ceiling, you want to light the walls.”
Building position and minimal windows on the east and west sides accomplishes part of this. Then, “you need strategies to control how light comes into the building,” he says. “If you have windows on the east or west, it's very tricky to do, but if you've got them on the south, you can have lightshelves both outside and inside; on the north, maybe just inside. The sunlight hits the shelf, and the light bounces and hits the ceiling, and hopefully is dispersed across the ceiling. The depth of the building you can light by daylight is determined by the height of the ceiling. So anything you can do to make the ceiling higher is a major benefit.”
One way to maximize ceiling height is to use underfloor heating, ventilation, and air conditioning systems — an energy-efficient method that's gaining in popularity. “Then you only have to run sprinklers and wires overhead; not ducts. You want the flow of air to start from the floor and move up to the ceiling,” Eubank says.
Another benefit is that floor space can be reconfigured. “When air comes from the ceiling, you are very constricted as to how you can set up dividers; you have to make sure everyone has the right amount of air. When it's under the floor, it's about as modular as the phone jack or the power cable, so you can end up putting the vents pretty much anywhere,” he says.
In Working Order
Older buildings require a different approach to energy savings. Every owner or potential owner should check existing equipment, energy use, and insulation to ensure maximum efficiency and cost-effectiveness. A variety of energy-modeling tools and software programs currently are available, including many available through local utility companies and equipment manufacturers such as Carrier and Trane. In order to optimize energy-efficient design, Eubank says, RMI recommends a computer program that models all elements of the building and its mechanical systems, and then simulates their operation throughout a full year, using weather data for the location for an entire average year. The granddaddy of these programs, he adds, is DOE2, created by the DOE, although there are simpler programs such as Energy Ten.
One idea gaining favor for older buildings is to commission the building, a process Eubank describes as “sort of like an energy audit on steroids.
“A technician and an engineer who are familiar with the operation of the equipment go in and test each piece of equipment to make sure that it's functioning the way it should,” he says. “And you typically find way more savings than it costs to do that study. We just don't think about it, but over time, these things stop working the way they're supposed to.”
Building owners also can save money by installing energy-saving equipment that's appropriate for the building's heating and air conditioning load. Energy management systems that adjust heating and cooling as they're needed (instead of running continuously) can make big changes in energy use and costs. However, it's important to first make other energy adjustments — lighting, windows, and office equipment — since so much of a building's heating and air conditioning use depends on these factors, Romm says.
Windows also are a key area for energy savings, which can be achieved through glazing, low-emissivity coatings, and low-conductivity gas. Such “superwindows” are expensive, but because their insulating values are so high, they save energy by reducing the size of the heating and cooling systems and allowing more daylight into the building.
Eubank cites a case study in which RMI was consulting a corporate owner renovating a 200,000-sf, 13-story office building. The 20-year-old structure had a glass curtainwall with inadequate insulation for its Chicago-area climate, and the owner was considering reglazing the whole building (which had a dark double-bronze glass as well as a gray sun-blocking film — a gloomy combination for its occupants), as well as renovating the air conditioning system.
RMI found that by installing improved windows, the building would be insulated three times as well, let in six times more daylight, and block excess solar heat. Combined with installing more efficient lighting and office equipment, the building's cooling load could be cut from 750 tons of air conditioning capacity to fewer than 200 tons. The cooling system could then be replaced — rather than simply renovated — with a smaller cooling system that was four times as efficient and $200,000 cheaper, which could not only pay for the other improvements but also cut the annual energy bill by $1.10 per square foot, a 75 percent reduction.
However, the owners vetoed the energy saving measures and stuck with their original renovation plan. The building then proved difficult to lease and was eventually sold at a distressed price.
But Gene Carr, CCIM, president of Carr & Associates in Atlanta, took advantage of energy savings when retrofitting a 15-year-old local office building two years ago. After replacing some equipment and performing simple maintenance, Carr brought down the building's summer energy consumption by 42 percent. (See sidebar.)
Assembling a Green Team
Finding the right architect, engineers, and designers to create the best design for a particular building is another challenge. While plenty of architects claim the “green” label, owners and developers need to know what to ask for. “You need to look at the integrated design picture,” Eubank says, which means that the designer looks not only at the equipment being upgraded but also how it affects other building elements.
Architects often lack the incentive to explore options to build in energy efficiency because they don't necessarily share in the long-term energy savings. This is why Eley Associates, a San Francisco architectural and engineering consulting firm, developed “performance contracting” for new construction. A performance contract lays out a target goal for energy consumption, then builds in methods to evaluate and measure performance after the building is in use. The design/build fee is then partially contingent on meeting the performance goal.
Although the operating cost savings have steered many toward energy efficiency, incentives also have become a powerful motivating tool. State and local utilities offer a variety of programs to promote energy-efficient design. The challenge, of course, is scouting out what is available in a particular state. “Start with your engineers,” advises Cheré LaRose-Senne, legislative analyst for the CCIM Institute. “They're going to know what's required, and what the incentives are.” A number of states also have incentives for newer alternative energy sources such as solar cells and wind turbines, Romm adds.
Owners and builders also have a national standards program, launched in March 2000, to help measure and build in energy efficiency and environmental sensitivity. Leadership in Energy and Environmental Design is a rating system developed by the Washington, D.C.-based U.S. Green Building Council, a consortium of some 800 organizations, including environmental groups, product manufacturers, architect and design groups, and building owners.
LEED is designed for rating new and existing commercial, institutional, and high-rise residential buildings. It grants credits for satisfying criteria ranging from water-efficient landscaping to chlorofluorocarbon reduction in HVAC equipment to thermal comfort. Buildings then are certified based on the number of points they earn: certified, silver, gold, or platinum.
Buildings registered during the design phase receive USGBC technical assistance and are certified upon completion. LEED currently has about 2.3 million sf of building space in the 16 projects that have been certified through the program; another 49.8 million sf — 244 projects — have been registered. USGBC also offers LEED training workshops and professional accrediting exams to help recognize green building specialists.
“The LEED system is a really powerful tool,” Eubank says. “If you're interviewing architects or doing a request for proposals, you can say, 'I want this to achieve a silver level.' Or take it even further and say, 'I want 50 percent less energy usage than standard office practice.' Then the team knows upfront going into the design that's expected.”
Buildings also can apply for the U.S. Environmental Protection Agency's Energy Star label. Like the LEED program, Energy Star also uses a scoring system as a “Statement of Energy Performance” for each building, which, says the EPA, “can help you formalize performance expectations to support leasing, building sales, appraisals, insurance, staff management, and energy/O&M service contracts.”
“It's amazing to see how many design firms are claiming green expertise, and it's very satisfying,” Eubank says. “And I don't think it's a flash in the pan. What I do hope is that it's a sea change in the way buildings are designed and that eventually green architects may be out of a job — which is fine, because it rightfully belongs in the everyday practice of engineers, architects, and other designers who work with buildings. It's almost like we're correcting something that went wrong 40-50 years ago, when air conditioning became prevalent and electric lighting became prevalent. The pendulum swung that way for a long time, and now I think it's coming back to a more rational look.”