Date: 04-Aug-09
Country: US
Author: Charles Redell

Green buildings are supposed to revolutionize the way the nation's built environment operates chiefly by using less energy. Seeing as U.S. commercial buildings account for about 30 percent of carbon emissions, according to the U.S. Green Building Council, improving the performance of the built environment is a key focus of all green building rating systems. But the green building industry has a dirty little secret: Until recently, few people really kept track of how so-called "high-performance buildings" were actually performing.

The main driver for green buildings in the United States is the U.S. Green Building Council's Leadership in Energy and Environmental Design (USGBC-LEED) rating system. LEED-certified buildings, at the basic Certified level, are designed to use 30 percent less energy than buildings built to standard code. It would make sense to assume that LEED-certified buildings at all levels do in fact perform as advertised.

"We're not seeing the true performance we might have expected [out of LEED-certified buildings]," says Jared Silliker, owner of Silliker + Partners, a green building-focused consulting firm based in Seattle.

A study released in March 2008 by New Buildings Institute (NBI) looked at 121 of U.S. buildings that were certified by the LEED for New Construction (LEED-NC) rating system through 2006. Of those, only 25 percent are performing better than their counterparts that were built to code.

The study, titled "Energy Performance of LEED for New Construction Buildings," showed a great deal of inconsistency in terms of many of the buildings' actual-versus-expected performance. Because performance data is being collected and analyzed for very few buildings, not many designers, building owners or operators even know if their buildings are performing as advertised. It's an issue of increasing concern, especially among insurance companies and law firms.

NBI's study included data on just 22 percent of all LEED-NC buildings certified in the United States in 2006. Getting the data for the worst-performing buildings in the study was very difficult because they were being operated "with no intention," says Mark Frankel, NBI's technical director. "We couldn't find anyone involved in the [maintenance and operations of the] building."

There are many parties that would benefit from having access to such data, however. Owners and operators may be spending more than necessary on energy or could have lower vacancy rates if they were able to show tenants that their bills would be lower. Engineers who understand what circumstances cause a spike in energy use may find it easier to manage those variables before they strike.Finally, building designers that follow the performance of completed, functioning buildings would learn what works and what doesn't, leading to more accurate modeling on future projects. Frankel notes that the accuracy of modeling is not very good, leaving designers in the dark about whether the model led to a building working the way it was intended.

"Architects hand off drawings and walk away and maybe check back in anecdotally," Silliker adds. "If architects could stay involved at a very small level for a little while, then some of those pieces might get caught." He's quick to point out, though, that the blame for a poorly operating building doesn't always fall on a designer's shoulders. It could be because of a problem in the mechanical systems or poor operations. The fault could even lie at the feet of tenants he says.

How to collect, analyze and get the data to the right parties remains a mystery to many despite a plethora of available frameworks. For example, Energy Star's Portfolio Manager provides an overview based on monthly reporting of numbers. This is a great start, according to Frankel, but it doesn't give enough detail to allow for any kind of meaningful troubleshooting. And the building manager has to be willing to input the numbers.

On the other side of the coin are very detailed data collection exercises that cost as much as hundreds of thousands of dollars because of the software and hardware requirements. They also generate massive amounts of data that are difficult to analyze. "No one has the time to sort through all the tons of data and understand what it means," Frankel says.

Things could be changing though. Silliker says he has been working on a project with St. Louis-based architecture and engineering firm HOK to help it track the emissions of its projects. Seattle-based Zimmer Gunsul Frasca Architects is undergoing a similar effort. And Seattle-based GGLO also undertook a multi-year study reviewing and comparing conventional and green developments.

"Gradually they're seeing the importance of knowing what their buildings eventually do," he says, adding it's a step he thinks is being supported by the current economic recession. With less financing available for new construction projects, there's renewed focus on LEED for Existing Buildings certification in the down market. Even new construction is likely to get in on the act however.With the release of the newest version of LEED-NC, often referred to as LEED v3, buildings seeking LEED certification are required to submit operational performance data on a recurring basis as a precondition to certification. If the building is found not to be performing as modeled, it risks de-certification, according to USGBC.

And with more design firms taking the 2030 Challenge and the Living Building Challenge-both of which require detailed energy-use data collection-measuring building performance is becoming a more common practice.

Finally, a recent spate of building labeling requirements in California, Washington, D.C., and Washington state require building owners and operators to make energy-use data available to prospective tenants and buyers.

At the federal level, an amendment to the American Clean Energy and Security Act, which passed the House of Representatives in June, sets up a voluntary building energy label for new homes and commercial buildings that would eventually provide funds to states to label buildings as they see fit.

"I think it's going to change the way we look at buildings," Frankel says about such labels.

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