Contractor turns new page in green building

M.A. Mortenson, the big construction company that built the new Minneapolis library, reused or recycled 95 percent of the old downtown library in the process -- not counting the books.

The project offers a prime example of the "greening" of the American building industry, thanks to rising energy and materials costs, as well as environmental considerations.

"We didn't adopt this mission for marketing purposes," said Dan Mehls, a Mortenson construction executive who oversaw the $138.5 million library project. "It's the right thing to do and where customers want us to go. They do not want to waste money, material, energy or pollute."

It's more economical in the long term to sell or recycle the old materials that are made into new steel, glass, road base and other material.

"We could have spent less upfront constructing that library," Mehls said. "It would have cost a lot more over time in energy and other operating costs. Sustainability is here to stay."

Mortenson expects the new 340,000-square-foot library to use only about three-quarters of the energy used annually by the older, slightly smaller library.

The new structure was designed by architect Cesar Pelli and Mortenson engineers to be nearly a third more efficient than the state energy code requires.

The library incorporates insulated glass and shading that uses the sun as a heat supplement in the colder months, roof gardens to mitigate summer heat and capture storm water, an under-floor ventilation system that should reduce heating and cooling costs by up to 20 percent, state-of-the art mechanical systems to increase efficiency and enhance indoor air quality and a high percentage of recycled content in the well-insulated building, according to an analysis by the Architectural Alliance.

Mortenson, still family-owned after 52 years and one of several national contractors based in the Twin Cities, including Opus and Ryan Companies, this year expects to report about $2 billion in revenue from its six regional offices. That makes it about the 35th-largest in the country.

The firm was founded by the late Mauritz Mortenson Sr. His son, M.A. Mortenson Jr., is the boss today. Mauritz Mortenson's father was a Swedish immigrant laborer.

Mortenson has received attention in the building industry for constructing the St. Mary's Duluth Clinic -- one of the first health facilities in the country to meet standards of the U.S. Green Building Council for Leadership in Energy and Environmental Design. Health care facilities are laggards in the industry, said Robert Cassidy, editor-in-chief of the trade magazine Building Design & Construction.

"Hospitals should be leading the way in providing patients, their families, doctors, nurses, technicians and office staff the ultimate sustainable experience," Cassidy wrote recently. "The reasons -- or excuses -- are all familiar: Hospitals are already heavily regulated. Hospitals are extremely complex structures. Hospital boards and CEOs are risk-averse. Hospitals suck up enormous amounts of air and water -- they're energy hogs -- so they can't possibly be made green."

The Green Building Council said building construction and operations account for 36 percent of U.S. fuel consumption, 12 percent of water consumption, 65 percent of electricity and 30 percent of greenhouse gas emissions. There's big savings and money in retrofitting and building anew efficiently.

Mortenson -- still digesting the office building boom of the late 1990s that has resulted in 20 percent vacancy rates in the Twin Cities and elsewhere -- has moved windward for growth. The company's biggest business: wind farms. Since 1998, Mortenson has constructed 45 wind-power plants in 16 states and Canada that generate 3,172 megawatts at peak capacity -- roughly enough to power 3 million households.

The company recently promoted Ken Sorenson, a Mortenson veteran, to run the Minnesota region. Mortenson is seeking higher visibility as it expects to bid on publicly funded stadiums for the Minnesota Twins and University of Minnesota.

In addition to the Wells Fargo Center downtown, Mortenson built the much-buzzed-about Walt Disney Concert Hall in Los Angeles, the Xcel Energy Center in St. Paul, Coors Field in Denver and the Walker Art Center.

The library, built with the help of $15 million-plus in private donations, met budget, despite some extra upfront expense for energy-conserving materials, Mehls said.

Neal St. Anthony • 612-673-7144 • nstanthony@startribune.com