Rachel Stone
Express-News Business Writer

A Zachry Construction Corp. building is the first in San Antonio to get one of the U.S. Green Building Council's highest certifications for energy efficiency.

The San Antonio-based company announced Friday that its employment and conference center on the city's South Side got a Leadership in Energy and Environmental Design Gold rating. It is the fifth Gold-certified LEED building in Texas.

LEED certifications are based on a points system that ranks buildings as Silver, Gold or Platinum, which is the highest rating. There is no LEED Platinum-certified building in San Antonio.

Green building is becoming a trend among architects, general contractors and local governments, and San Antonio is catching on. City Council last month passed a resolution requiring that every new city building must earn at least a Silver LEED rating. When the American Institute of Architects held its annual meeting here recently, green building was the convention's theme.

"I think the Zachry company is setting an extraordinary example of what responsible building is," said City Councilman Richard Perez, who took a tour of the building Friday after the announcement ceremony. The building is in his district. "It's a statement on their part saying it can be done."

The company renovated a 20,000-square-foot former warehouse made of brick into what officially is the greenest commercial building in San Antonio so far.

The building is about 27 percent more energy-efficient than a typical office building, according to Zachary officials.

It features a daylight harvesting system, which measures the amount of sunlight coming in through windows and then adjusts the electric lights accordingly. That's a perk that reduces electricity costs and keeps productivity high, since studies show that people report feeling better overall working in daylight rather than under fluorescent lights.

Solar panels provide 5.5 percent of the building's electricity.

Rainwater is harvested for flushing toilets; and a gray-water system collects water from sinks, fountains and showers for landscape irrigation.

The standard asphalt parking lot was replaced with gardens, crushed granite and permeable concrete.

Much of the building was constructed using recycled materials, salvaged goods and renewable materials, including boards made from wheat chaff, cork flooring and fabric wall coverings made from grasses.

The $5 million renovation cost about 15 percent more than a non-green building, said Rene Garcia, head of the company's commercial building division. Garcia noted, though, that the energy savings would offset the extra construction costs within five years.

"The past perception was that you'd have to spend a lot of time and money," he said. "But the industry is catching up, and we found that the market is leaning toward supporting green building."

Zachry wants to encourage its clients to build green, he said.

"We wanted to learn about the LEED process, and we wanted to get the highest rating we could," Garcia said.

The work of a construction company typically is to demolish old buildings and to put up new ones, which creates waste.

In Zachry's LEED-rated building, 90 percent of the materials were salvaged and donated to churches and nonprofit groups or sold for reuse after interior demolition. That saved 679 tons of waste — more than 11/2 times the weight of a Boeing 747 airplane — from becoming landfill.

Kell Muñoz Architects redesigned the building, which opened in April 2006 and took about two years to complete.