Posted: November 01, 2011
Sustainable construction: A century-old concept
New technology has spurred energy savings, but the best architects and builders have always sought efficiency
By Stephen Titus
In the earliest days of former Gov. Bill Ritter's tenure, he issued an executive order requiring all state-run universities to reduce energy and water usage 10 percent to 20 percent by 2012.
The private sector was way ahead of him, with new materials and technologies that could easily reach these goals and more. Campuses around the state responded, and today many are already there with some, like CU Boulder, going beyond and already employing ways to save twice this amount.
Sustainable construction and architecture techniques are a hot topic these days, but architects who have been around a while point out that they are nothing new. The best in this business have always sought the most efficient, livable design and even the oldest of those structures are still around today. What has changed is demand for energy efficiency and an overall reduction in resources and waste.
This has led to a drop in prices for materials and techniques that, when applied to age-old wisdom and new-age technology, produce energy-efficient structures that just a decade ago would have been impossible to build on a "normal" budget. These materials and techniques are now used in nearly every new building under construction today.
"The cost of green building is going down," said Sarah Armstrong, manager of business development and marketing for Colorado-based FCI Constructors. "Building materials, like low VOC paints and carpet and recycled content material, is nearly matching the price of standard (materials). The demand is so high, the cost is going down significantly over three or four years ago."
Even buildings labeled as affordable housing are meeting the highest green-build standards and doing it on a tight budget. FCI Constructors built the award-winning Renaissance Riverfront Lofts. Designed by Page Southerland Page Architects in Denver for the Colorado Coalition for the Homeless, Renaissance Riverfront Lofts blends seamlessly into the neighborhood at Interstate 25 and Park Avenue. It's a five-story apartment building for the homeless and those in need of affordable housing. It was recently completed to LEED Gold standard (Leadership in Energy and Environmental Design,) which is well beyond many of the high-end loft projects in the Platte River valley.
Designing buildings with an eye toward the local environment and to take advantage of passive solar heating and natural ventilation has been part of the design equation for the past 100 years or more. Philadelphia architect Charles Klauder designed buildings on the CU Boulder campus in the early 1900s with local limestone that was good at holding heat in the winter and avoided expensive shipping costs associated with materials from outside the state. He oriented buildings, and the windows and doors, to take advantage of natural ventilation and shading. His choice of materials and architectural style set the format for nearly every future building on the campus.
"Building orientation, mass of the buildings, how shade affects the structure, this was intuitive to the design," said Chris Carvell, design principal with Page Southerland Page. "It's a high-plains desert. How would you provide buildings that extend cover and shelter, that would respond to both winter and summer climate issues?"
Carvell was involved in the design of the CU Boulder mathematics and engineerng library. Architects in CU's Department of Planning Design and Construction have made sustainable design and building construction a focus for the past decade and are laying the groundwork to make all future structures on the campus at or near net-zero energy consumption, which means they create or reuse energy and water resources in a way that reduces the need from outside sources to almost zero.
"I think it's an aspiration more than a goal," said Paul Leef, director of Campus Design and Construction. "We take a very businesslike approach when looking at the design of our buildings, looking at life span and return on investment. Our basic goal is to pursue what we call LEED Gold Plus. This goes beyond Gold but focuses on water conservation as well."
Williams Village North was built to LEED Gold Plus standards, and the new biotechnology center, currently under construction, is on track for LEED Platinum, the highest rating. Moe Tabrizi, campus sustainability director, said there are eight buildings on campus built to LEED Gold or higher and another eight under construction that will meet or exceed those standards. He said these buildings are 30 percent to 40 percent more energy efficient than simply code-compliant buildings. With a campus-wide annual utility bill of about $25 million, the potential savings are enormous.
"For example, Wolf Law (School), I think the premium that went into LEED and sustainable features was $300,000, and the annual utility savings is $250,000 per year," Tabrizi said. "That's a 1.2 year payback, and these buildings will be here for 30 to 50 years."
Tabrizi added that some of the water conservation techniques like recycling gray water or roof runoff for flushing toilets have not yet been implemented due to arcane water law in Colorado. He's working with the city and state to gain approval for the systems he believes will further reduce costs if they can be expanded to other buildings. Techniques like light sensors that turn off lights and adjust heat or cooling levels when a room is empty or automatically lowers the shutters if a room is overheated from the sun are also important components of the plan.
But the cheap, low-tech practices are also part of the equation. Heightened awareness through the use of signs and stickers reminding students and staff to reduce energy consumption and report waste is making an equally large impact and creating more environmentally aware students and faculty. These are used in older buildings as well, along with light sensors and other technology that can be retrofitted to every structure on campus.
Perhaps most surprising, CU has made the most expensive and high-tech changes like using photovoltaic electricity generation and geothermal heating with funding from outside the university.
"Our claim to fame is we have designed, financed and implemented these without money from campus budgets. We've paid for these with rebates and tax credits," Tabrizi said.
Tabrizi and Leef say the goal going forward is to have all new buildings at or near net-zero energy consumption in 10 years, and in 20 years to be carbon neutral.
"Is it possible? Yes. Is it going to be a big challenge? Yes. Is it going to happen overnight? No. It will take some time," Tabrizi said. "I think in 10 years a lot of people will talk about net zero buildings; 10 years ago no one knew about LEED. Now it's the standard."