Impressive as PNC Bank’s unveiling of its LEED-Platinum office tower—“the greenest in the world”—was for green building aficionados at the Cleveland Museum of Natural History, how engineers plan to translate lessons to the Museum’s building expansion project was just as ripe a topic.
Denzil Gallagher, Principal with BuroHappold Engineering, whose firm is working on both the bank and the museum projects, explained how nature can be helpful in doing some of the heavy lifting.
“Passive first,” said Gallagher. “It means we look at the building’s form, shape, context in the city, what enclosures look like, what we can do to shape it, and how to orient it to take advantage of or shield it from the sun.”
Design before bringing in high-end technologies—like the Tower’s energy recovery ventilation unit and its water recovery / bio-recycling system that will reduce water use by 72 percent. Their goal is to reduce energy use by 50% of a conventional building.
First, they “twisted” the building, just so, from the axis on the downtown Pittsburgh street grid, in order to better face the sun. The engineering marvel, though, is a double-glass facade that uses automated dampers that will open and shut to capture or release air warmed by the sun up to 120 degrees Fahrenheit. Two shafts at the center and a “solar chimney" at the roof will work with gravity to move the warm air either out or inside depending on the needs of its 2,200 occupants.
Analysis showed that 42% of the calendar year are in the ideal temperature range in the city to use outside air, Gallagher said. This marks the first modern high rise in the U.S. to work with natural ventilation, he added.
The building “breathes” noted Harvey Webster, Director of Wildlife Resources at CMNH and the evening’s moderator. “That also has to give it a greater sense of health for its occupants.”
Indeed, health and occupant satisfaction is a major driver, said Kate Zettl, Energy Analyst for PNC, which owns the largest portfolio of green buildings in corporate America. Along with natural air, the building’s narrow width (35 feet) provides 92% of the inside with daylight, which helps to boost productivity and reduce the need for artificial light, said PNC Sustainability Analyst, Angelica Ciranni.
A space that models the outdoors and blends with nature are just as important for the Museum, said GreenCityBlueLake Director, David Beach, as indicators of energy and water use. The Museum has set targets to reduce energy by 25% and water use by 35%.
Like PNC, the Natural History Museum is tracking a new green building rating system known as the Well Building Standard, said BuroHappold Associate Principal, Sarah Sachs, which has a special focus on air quality, natural light, healthy food offerings, and more people-focused elements.
The Museum will also demonstrate sustainability in planting its Perkins Wildlife Garden with native plants, a wetland, and a bioswale and build furniture and fencing from wood recycled from the old garden. The Museum also released an RFP looking for an installer to place a solar PV array on top of its new parking deck, Beach said.
“Buildings account for 50 percent of our carbon emissions,” he concluded. “If we don’t get buildings right, we’ll never get to our climate change obligations.”