The green building movement has spurred a new generation of energy-efficient and high-tech properties. Yet many firms are setting their standards even higher. Driven by climate change concerns, architects and designers are increasingly in pursuit of projects with little to no carbon footprint. Their efforts couldn’t come at a more urgent time. Buildings account for nearly 40 percent of annual greenhouse gas emissions due to energy use and carbon-intensive materials like steel and concrete, and annual emissions continue to rise as the global building stock grows.
More than 600 firms have joined the 2030 Challenge, an industry initiative to design new buildings and major renovations carbon neutral—meaning they reduce or offset operational emissions until the net result is zero. To support the goal, the American Institute of Architects (AIA) has developed tools to help track progress and evaluate decisions. “Climate change is an all hands on deck crisis, and everyone has a role,” says Tate Walker, OPN Architects’ director of sustainability, who co-chairs the AIA’s carbon neutral effort. “Architects have the skills to envision what a good future looks like.” Here, we look at four firms leading the way through innovative design, sustainable materials, and renewable energy investments.
For Oslo-based multidisciplinary firm Snøhetta, the future of sustainable design looks a lot like its Powerhouse Brattørkaia. Completed last September, the angular office building overlooks a fjord in central Norway. Nearly 33,000 square feet of solar panels blanket the upper façade and pentagon-shaped roof, which is steeply angled to capture as much daylight as possible. The complex is designed as carbon negative, with panels that will produce far more clean electricity than the building consumes. The goal is not only to cancel out its carbon emissions from over 60 years of operation, but also those created during construction and demolition phases.
In fact, Snøhetta and other industry partners developed the Powerhouse standard to designate super-efficient projects. Up next, the circular Svart hotel, at the foot of the Svartisen glacier in Norway, has a mission to reduce its energy consumption by 85 percent compared with new hotels. “Our ambition is to exceed [carbon] neutrality, both to light the way and to help compensate for parts of the building industry that will undoubtedly be slower to adapt,” says Aaron Dorf, a director at Snøhetta’s New York office. “We don’t yet get to decide the carbon neutrality of our own work, though we are urging clients and partners on all of our projects to do more to address climate change.”
When HOK began designing Royal Caribbean’s 350,000-square-foot headquarters in Miami, the team mulled a decision to extend floors past the windows. Deep overhangs might block daylight and waterfront views for office workers, but the extra shade would cool the building. The team crunched the numbers. Models showed that, without shading, the building would need to increase cooling systems by 13 percent, adding considerable costs; alternately, designers could cut the wall-to-window ratio in half. The overhangs won.
Anica Landreneau, who leads HOK’s sustainable design initiatives, says that modeling how, where, and when buildings consume energy is the key to driving smart design decisions. The Royal Caribbean office, which is slated to open in 2024, is shaped like a boomerang to allow daylighting across a higher percentage of floor space, while its overhangs keep the sun’s heat in check.
Meanwhile, at the New York-Presbyterian David H. Koch Center in Manhattan, the building’s skin includes triple-paned insulated glazing with a slatted wood screen, which helps reduce solar glare and cools the building while providing privacy shading.
Landreneau says that extra costs, complexities, and client preferences pose a challenge to carbon neutrality. HOK has achieved about a 60 percent reduction in its portfolio’s predicted energy use since joining the 2030 Challenge, with only a decade left to reach its final goal. “We’re continuing to work on that,” Landreneau says. “If we don’t, we won’t get anywhere.”
At the Goldsmith Street residences in Norwich, England, timber frames support walls filled with recycled newspapers. The 100-home project, designed by London studio Mikhail Riches, faces south to soak in plenty of daylight. Community gardens, which bring neighbors together, also capture rainwater. The low-rise, high-density development is the largest UK project to meet the exacting standards of Passivhaus, a voluntary initiative for designing ultra-low energy buildings. Last year, after winning the RIBA Stirling Prize for Goldsmith Street, the firm said it would work only on zero carbon projects going forward.
“As architects, we have a chance to be leaders in this field, and as eternal optimists, we see this as an opportunity to develop new design approaches,” says Oliver Bulleid, director at Mikhail Riches. Until recently, the firm primarily focused on reducing energy usage from building operations, like heating and water. Now, architects concentrate more on curbing emissions from construction materials. Clay Field, an affordable housing complex in Suffolk, employs frames of sustainably grown timber and is insulated with a mixture of hemp and lime. Both materials can help trap carbon in place, rather than release it into the air.
“Older buildings are often built with local materials that are assembled very simply and address both function and climate. This approach is inherently sustainable,” Bulleid says. “We enjoy studying and understanding what works well historically and using this to inform our design approach.” He says the firm is finding that well-designed, low-energy projects often cost only slightly more than those meeting minimum sustainability standards. As more local city councils declare climate emergencies and set zero-carbon building goals, Mikhail Riches is partnering with authorities to help create more affordable, sustainable communities.
Texas architecture firm Lake Flato strives to design buildings that reflect the local culture and climate. From an environmental perspective, that means figuring out how to reduce energy consumption and source local materials. “The strategies you use to get to carbon reductions are going to be different in the hot, humid U.S. South than in Upstate New York,” says Heather Holdridge, sustainability director and an associate partner in the firm’s San Antonio office. “Those are the kinds of challenges that we’re grappling with.”
As a 2030 Challenge participant, Lake Flato uses the AIA’s complementary tools to track carbon emissions from its building operations. But the firm is increasingly focused on measuring and understanding the embodied carbon in construction materials. For Bunkhouse Group’s Hotel Magdalena in Austin, the architects opted primarily to use mass timber—engineered wood products with a lower-emissions profile that also lock carbon in panels, posts, and beams. The 47,000-square-foot property will be the first mass timber boutique hotel in North America upon its completion this spring.
At the Lodge at Gulf State Park, a Hilton hotel in Alabama with interiors by Looney & Associates, Lake Flato found other ways to reduce the project’s footprint. Each guestroom has operable windows that are directly tied to thermostats, so guests can naturally ventilate their rooms without unnecessarily using heating or cooling systems. The hotel also captures condensate from air-conditioning units, which in turn fill up the swimming pool to reduce the use of potable water. Holdridge says her team has learned that carbon-neutral buildings can’t exist without carbon-neutral occupants. “They need to understand how their behavior impacts it,” she says. “You have to have the owners and users engage with that goal.”
Photos and renderings by Ivar Kvaal, Eric Laignel, Frank Oudeman, RAS Photography, Tim Crocker, and Julie Soefer Photography
This article originally appeared in HD’s March/April 2020 issue.