Green Buildings Don’t Have to Compromise Longevity, Maintenence
By Loren Snyder - June 2008 - Green
Environmental awareness has been increasing steadily since the 1970s. In buildings, that has meant CFC-free chillers and low VOC paints, recycling programs and products with recycled content. And in the past few years, it has meant a boom in the construction of green buildings.
But as interest in the environment has increased, green has become fashionable. Companies tout their efforts to become sustainable in expensive advertising campaigns, popular magazines offer advice about green life style choices, and a growing array of products promise low environmental impact the way food companies tout low fat or low sodium.
At the core of the idea of green is good intent. But problems can arise when good ideas become fashionable. And as sound as the concept of sustainability is, facility executives and the design community run the risk of getting caught up in what can amount to hype, with potentially detrimental effects on building performance.
Ultimately, for the concept of sustainability to work in a given structure, facility executives need to be mindful that building systems operate as a whole, not as separate entities. They also need to watch for misguided specs from designers. For example, systems that work in cold, dry climates may fail prematurely in warm, humid ones.
Finally, each organization has different requirements when validating what “green” means; organizations that are aware of their internal needs and mandates are much more successful in achieving sustainability than those that aren’t.
There is a growing consensus that sustainability should be at the heart of the way buildings are designed. But in the quest to create increasingly more sophisticated, sustainable buildings, it is possible to lose sight of exactly what makes buildings environmentally responsible. The problem, some observers say, is that the design process can be transmogrified into marketing schemes with promises that don’t always hold true once a building is built. Tim Pennigar, the project manager of structural systems for Duke University Health System, cites the emphasis on cool roof membranes as an example of the problems that can arise.
“The emphasis is good, but then we see that they are put into an assembly that won’t last more than 10 or 15 years, because they weren’t thoughtfully designed into a system,” Pennigar says.
A wide range of green products has come to the market during the last 10 years. That’s been a boon to green construction. But just using green building materials isn’t enough when a conventional design and construction process is used.
“Ultimately, there’s something fundamentally wrong with the way that we design buildings,” says Pennigar. “The next step is to move past specific products. They need to be integrated.”
Green design experts agree that integrated design is at the heart of a well designed green building. And a truly integrated design process should involve all members of the team — including operations and maintenance staff. Tasked with the duties of keeping systems running long after architects and designers move on to other projects, operations staff are vital to identifying potential pitfalls during the design phase.
A good first step, says George DuBose, vice president at Liberty Buildings, is a thorough integration of the design and construction of the building envelope with the design and installation of the HVAC system.
“Typically these are designed in a vacuum,” DuBose says, “and that can lead to problems.”
Others agree, saying that the construction of green buildings requires more thought than has previously been given to buildings during the last half century, whether they’ve been green from the design outset or not.
“Put behind you what you’ve done for the last 20 jobs,” says Scott Frank, partner with Jaros Baum & Bolles. “Get in the habit of saying, ‘How can we do this differently?’ Ask ‘Why not?’ at every turn. Worship common sense. And be sure every decision and recommendation you make is backed up by rigorous engineering.”
Sustainability, Durability, Suitability
It is not enough to specify or approve products simply because they are purported to be sustainable or can help earn LEED credits. Rather, facility executives should be clear about the larger implications of the term “sustainability.”
According to Pennigar, one starting point for most organizations, including his, is to determine a team definition of sustainability.
“It’s a loaded term that can evoke great delight or glassy-eyed cynicism among members of your construction team,” says Pennigar. “Largely, users of the term have a material and toxicity focus, or an emphasis on renewable natural resources. Clearly, these are vitally important issues.”
But the concept of sustainability includes environmental considerations that extend well beyond the characteristics of individual materials. Based upon the interaction of various building systems, facility executives should weight questions about inherent durability, maintainability and flexibility of the component parts — including adaptive reuse.
“A LEED-applicable roofing system that fails prematurely because of inferior quality or misapplication does not look very sustainable buried in a landfill,” Pennigar says.
Green design is more than just using materials with low VOC emissions or a high percentage of recycled content, as useful as those can be in a well-thought-out green design strategy. In some cases, re-using materials already on hand is more beneficial for the environment than purchasing the latest green materials and disposing of the old.
On the Duke campus, a 2007 roof replacement managed to salvage 90 percent of the insulation, diverting 718 tons of solid waste. Salvaged materials from this effort included 296,000 board feet of XPS insulation — all of which has been reused in new roofing construction on two Duke buildings.
Facility executives responsible for high-performing buildings also need to work with architects, designers and operations staff to help ensure that all mechanical systems are operated as intended.
One problem, according to HOK Project Architect JoAnn Brookes, is that facility staff might not fully understand how modern, complex building systems operate.
In high-performing buildings, inadvertently changing ideal building performance setpoints can wreak havoc. Brookes cites the case of a previously balanced building in which HVAC setpoints were adjusted. The building ended up with an energy-robbing cold plenum.
Other experts contend that, in the push for new energy-efficiency capabilities, designers and facility executives can create additional problems — often with water vapor inside the building membrane.
Pennigar points to an example from his campus: “We often seem to have tension between the demand for interior air quality and energy conservation. HVAC building control elements included in LEED are sometimes in conflict with real-world conditions in an occupied building, although some of these conflicts are currently being addressed in new iterations of LEED guidelines.” Many experts note that buildings in hot, humid climates require more conditioning of air than buildings in other places. Doing that means using more energy, but failing to do it can mean problems with occupant comfort or moisture getting into building components.
Avoiding Problems With Green Designs
In discussing suitability, facility executives, architects and engineers need to remain mindful that HVAC systems which work — for example — in dry northern climates might cause premature and catastrophic failures of envelope insulation systems located in warm, humid climates.
“So many green design strategies are driving putting more air into buildings,” says DuBose, “and this can cause problems.”
Similarly, Pennigar contends that the term vapor barrier — a design strategy often used in green buildings — should be stricken from design vocabulary.
“Air leakage or vapor convection has hundreds of times more capacity than vapor diffusion for the transport of moisture within a wall assembly,” he says. “In the real world, the idea of constructing an exclusionary barrier to anything is folly, and design energies would be better focused on strategies to eliminate or control air infiltration, realizing, of course, that 100 percent exclusion is impossible.” For Pennigar and others, it makes far more sense to focus on closing holes, gaps, and spaces in the building envelope than to worry about vapor barriers.
Pennigar also admits that Duke has traditionally used architectural firms from northern regions of the U.S. — not all of which have understood the mixed year-round climate in North Carolina.
Another problem that Pennigar sees is reuse of existing plans, saying that some plans appear to be “cut-and-paste” jobs that are recycled from previous designs and that do not give careful consideration to site design and needs. Rigorously applied engineering standards would combat that problem, but Pennigar admits that adhering to those standards may be difficult.
“There are pressures from without and within to move paper, fast-track design, and that leads to unrealistic time frames and deadlines,” Pennigar says.
The bottom line: proper green design may take a bit more time on the planning and design front.
For facility executives in an existing building, DuBose recommends that retro-commissioning be performed to determine and fix any building-wide performance problems. “These include things like poor pressurization issues, dehumidification issues, and chronic water-intrusion issues,” he says.
For new buildings, DuBose recommends using green strategies that also conform to the climate where the building will be situated. He further recommends that facility executives ask for help, and rely on peer review activities to monitor and assist design development.
Pennigar agrees. “At the very least, buying a few hours of consultant time to simply review a set of design development drawings can be of tremendous value to an owner or manager — either to affirm competency or to raise a flag for closer scrutiny of a designer’s skills.”
The value of that approach isn’t limited to green buildings. Recently, a leakage path was isolated at the intersection of four dissimilar cladding systems on one of the buildings on Duke’s campus.
“While we encourage creativity, we do ask that the designer invest at least as much energy in making our buildings as reliable and durable as they are engaging and beautiful,” Pennigar says.
The same thing can be said of green design. A building that isn’t suitable, durable and maintainable doesn’t qualify as being sustainable.
Engage Operations Staff
But the onus is not entirely on the designer. It’s essential for facility executives to get operational staff involved in the design process. Operational and maintenance staff care for buildings after the architects’ and designers’ work is done. They need to have access to plans, because they can tell designers if, for example, an access panel to a piece of mechanical equipment would be hidden behind drywall. But it’s up to the facility staff to speak up, realizing how important their input is to the longevity of the facility.
“The final chapter of this story,” Pennigar says, “is when operations managers realize their importance in the maintainability of modern buildings.”
Loren Snyder, a contributing editor for Building Operating Management, is a writer who specializes in facility issues. He was formerly the magazine’s managing editor.
DESIGN FOR SUITABILITY
A Modest Proposal
Form vs. function is an age-old debate. One potential unintended consequence of designing photogenic buildings is that, mechanically speaking, operations and livability can be compromised. Organizations should certainly seek engaging new buildings, but should not lose sight of the vital nature of service and function.
The same holds true for green buildings. Tim Pennigar, the project manager of structural systems for Duke University Health System, suggests a novel way to circumvent this potential pitfall.
“What if owners started basing their design team selection on positive feedback from facility managers living in the prospective design firm’s award winning buildings? I think we assume that service and function is standard operating procedure in building design.”
— Loren Snyder