The results of two recent studies—one carried out by the NewBuildings Institute {NBI}, the other by CoStar Group—show that greenbuilding standards are not only effective, but also escalate propertyvalues.  The post-occupancy studies, both released in March, attemptedto measure the value of buildings with sustainability features comparedto conventional buildings. They also aimed to demonstrate theeffectiveness of third-party certification programs, specifically LEED,administered by the U.S. Green Building Council {USGBC}, and EnergyStar, managed by the Environmental Protection Agency and the U.S.Department of Energy.

One study confirmed that newLEED-certified buildings use less energy than non-certified buildings.Commissioned and funded by the USGBC, the study was conducted by theNBI, a nonprofit organization in the Pacific Northwest that specializesin providing information about sustainable architecture. Researcherscompared data on energy use intensities collected from 121LEED-certified buildings to statistics from an energy survey conductedby the federal government in 2007.

The NBI study foundthat the median energy-use intensity {EUI, as measured by kBtu persquare foot per year} for LEED buildings is 24 percent better thanthe national average for conventional buildings. When divided intotypologies, office buildings demonstrated the most significantdifference. LEED-certified offices performed 33  percent better, andthose with a Gold or Platinum rating performed 50 percent better. Theseresults underscore one of the study’s other prevailing findings: that,in most cases, buildings perform better as they get higher ratings,between certified, Silver, Gold, and Platinum.

The NBI study results weren’t entirely positive. Surprisingly, theactual EUI performance for LEED-certified, high-energy-use buildings,such as laboratories and data centers, was nearly two-and-a-half timeshigher than what was predicted during their design. The report callsthis “very poor, even on average,” and suggests that performancemodeling is in dire need of rethinking. Andrew McNamara, director ofnew construction services at Bright Power, a New York-based energyconsultancy, says he was surprised by the drastic underperformance ofsome LEED-certified buildings. Projects that were supposed to seeenergy savings of up to 40 percent actually “underperformed code by 60percent.” “The NBI study provides a much-needed comparison of energymodels to reality,” he says.

The Maryland-based CoStar Group, a provider ofcommercial property information, undertook a separate study,investigating green building real estate trends by analyzing propertyvalues and occupancy rates. The study used a pool of more than 1,300buildings, representing about 351 million square feet.  Results showedthat Energy Star buildings on the market commanded an additional $61per square foot. They also showed that rental rates for Energy Starbuildings are $2.40 per square foot higher than those in non-certifiedbuildings—and occupancy rates are 3.6 percent higher. In addition,CoStar discovered that LEED-certified buildings are selling for $171per square foot more than non-certified buildings. In terms of rentalprices, a LEED-certified building fetches an extra $11.24 per squarefoot.