For the first time in human history, atmospheric CO2 levels surpassed 400ppm, before, two years later, hitting 410ppm, a level that hasn’t occurred for millions of years. Thus, we have increased planetary temperatures 1.5°C (2.7°F) above preindustrial levels as we head toward temperatures that will set off runaway climate destabilization.
The effects are already being felt globally. Countries poor and rich alike have been plagued with hurricanes and other storms exacerbated by excess moisture generated by global warming, causing some island nations to literally drown. Additionally, record droughts, wildfires, snowstorms and cold snaps are affecting the world’s food supplies.
As parts of the global society wake up to the reality of climate change, some in the architecture, engineering and construction (AEC) industry are looking to what they can do to make our buildings and infrastructure more ecologically sustainable, thus reducing the greenhouse gases (GHGs) pumped into the air—or more resilient—and thereby protecting the structures against extreme weather.
We spoke to a number of experts in the AEC arena to learn how the industry is adapting to the changing world brought about by climate change.
The Carbon Footprint of Buildings and Cities
Around the world, construction accounts for about 25 percent of GHG emissions.In terms of infrastructure, large cities consume two-thirds of the world’s energy, resulting in 70 percent of the world’s CO2 emissions.
There are two major ways that the AEC industry might respond to climate change: reducing the environmental impact of buildings and infrastructure (often referred to as sustainable practices) and bracing for the impacts of climate change that are already occurring (often referred to as resilience).
Resilient design considers the impacts of extreme weather—such as flooding, overheating, power outages—and attempts to protect against them.Lisa Dickson,associate principal and director of resilience for the Americas at the Arup Group, noted the necessary changes required in the AEC industry when it comes to climate change:
“There’s an increase in both the frequency and severity of these weather events as we move toward present day. There has been over $1.5 trillion of natural disaster impacts since 1980. This is layered on top of a nearly $4 trillion gap in infrastructure funding needs by 2025, which currently represents 20 percent of the U.S. GDP,” Dickson said. “We fundamentally have to change the way we approach infrastructure to be much more proactive in making it resilient, looking longer term.”
Flooding and Extreme Rain
Dickson pointed out that there is a great deal of focus placed on flooding related to sea level rise and storm surges. More recently, there has also been greater awareness that precipitation-related floods are increasing, are dropping a greater volume of water in more compressed periods of time, and may often be followed by periods of relative drought.
In New York, Arup has helped redevelop 20 acres of post-industrial waterfront on Long Island into Hunters Point South Waterfront Park, where it acts as a storm surge barrier for the largest affordable housing building project in New York City. The park was built with a 100-year-storm elevation, plus an extra seven feet.(Image courtesy of NYC Parks.)
A compounding issue is the fact that many coastal storms, which generate surges, can occur at the same time that intense precipitation takes place on land. While a sea wall could be used to impede the flow of the ocean, it would, unfortunately, also act as a dam for the storm water that would need to be flushed out to a nearby bay.
Based on studies Arup has performed, Dickson had very frank and startling projections for the future, when it came to extreme heat. “Using Boston as an example, looking out to 2070, if you consider summer as occurring between June and August, every day could see temperatures of above 90 degrees [Fahrenheit],” Dickson said. “By 2070, Boston’s entire summer could be an extended heat wave.”
(Image courtesy of the U.S. Environmental Protection Agency.)
These extreme temperatures are exaggerated in cities, where the urban heat island effect (UHI), caused by an increased number of dark surfaces, a lack of vegetation, and the ability of light to reflect off of and absorb into more surfaces in cities with tall buildings. In China, UHI is thought to contribute to climate warming by roughly 30 percent. In turn, cities consume higher levels of electricity, due to the use of air conditioning systems.
One key strategy to reduce UHI is the use of light-colored surfaces, for example, replacing dark roofs with light colors, using reflective materials, or painting roads white to enhance the city’s overall albedo effect—the reflection of the sun’s light back into the atmosphere. This also aids, to a small extent, the planet’s albedo effect, which is being decreased by the melting of the planet’s ice caps. Green roofs, in which vegetation adorns the tops of buildings, can create an albedo effect, while also acting as insulation, absorbing CO2 and providing food.
In a comparison between white and black test plots on the roof of the Museum of Modern Art in Queens, New York, the white surface temperature measured 40°F cooler than those painted black during a period of June to August 2011. (Image courtesy of Gaffin et al.)
Dickson said that extreme heat is having a significant impact on the cooling systems of buildings, as well as on public health and safety. This includes implications for the labor force, as it can affect whether or not people can work outside and whether or not they can bike to work or wait outdoors for a bus.Such extreme temperatures will also have impacts on the tourism industry and the number of people who will visit a city during the summer.
On the other end of the extreme temperature spectrum is the wobbly polar vortex, an area of cold air with low atmospheric pressure that hovers over the Arctic. At the edges of the vortex is the polar jet stream, which is a fast-flowing air current that travels around the planet between the Arctic and mid-latitude regions.
In the past, a large temperature difference between the vortex and the mid-latitude regions would drive the jet stream in such a way that the cold air of the Arctic would be herded at the North Pole. As the Arctic experiences warming faster than other regions on the planet, the jet stream has been wobbling north and south, instead of maintaining its tight circular path around the Earth. This has caused more of the cold Arctic climate to be driven down to the mid-latitudes.
“So, not only are we dealing with the extreme heat during the summer, but extreme cold during the winter,” Dickson said.“What does that mean in terms of financing something with a 100-degree differential?”
Health Care That Weathers the Storm
One Arup client that has taken climate change extremely seriously for all of its facilities is Partners HealthCare, a health-care network in New England. To learn more, we spoke with Dr. Paul Biddinger, director of the Center for Disaster Medicine and vice chairman for emergency preparedness at Massachusetts General Hospital in Boston, as well as the medical director for emergency preparedness at Partners HealthCare.
Spaulding Rehabilitation Hospital in Boston is built 30 inches above the 500-year flood elevation and uses bioswales and granite berms to prevent flooding. (Image courtesy of Steinkamp Photography.)
Biddinger explained that Partners is deploying resilience measures across its more than 30 facilities, including existing hospitals and offices, as well as new buildings. Among these solutions are those related to heavy precipitation, flooding and storm surges. For instance, Partners is making its electrical systems and emergency generators more able to withstand such events. Partners is also looking to Dutch designs to explore flood barriers that can be deployed to prevent ground floor penetrations of flood waters.
“Learning lessons from Sandy and Katrina, we’re moving generators above grade,” Biddinger said. “For those things that can’t be moved above grade, like fuel tanks and fuel pumps, we’re making them fully watertight, trying to make sure that all of the switch gear is appropriately watertight as well, so that all components of the electrical system are resilient to flooding.”
Biddinger explained that Partners is aiming to make some of its facilities places of refuge or “extra resilient,” so that patients who are at high risk in extreme storm events can escape to Partners hospitals. To do so, the organization is exploring putting submarine doors in select below-ground floor areas. This will make it possible to wall off safe places in the basements of buildings for supplies and food storage.
Key-operated windows at Spaulding Rehabilitation Center make it possible for staff to let in natural air, in the eventof an emergency. (Image courtesy of Steinkamp Photography.)
“It’s not necessarily only about protecting the facility during the event but also making sure that for the period of recovery afterward we can continue operations,” Biddinger explained. “A couple of our facilities are in vulnerable areas, so that, even if they’re not damaged by the flooding, they can become isolated, so it’s difficult to get supplies in or out.”
Biddinger pointed out that New England is especially vulnerable when it comes to increasing high temperatures in the future, because the region’snot as accustomed to the phenomena. Emergency generators may not be able to power cooling systems sufficiently. Therefore, Partners is determining how to bring extra power generation capabilities in the case of power loss or brownouts, thus preventing the need to evacuate patients from facilities.
Green roofs and terraces at Spaulding Rehabilitation Center help control storm runoff while also enacting the albedo effect. (Image courtesy of Steinkamp Photography.)
Chicago architecture firm Farr Associates has been implementing sustainability in its practice since before the word “sustainability” even became widespread.
The Yannell House has 96 windows that limit the need for the use of lighting, as well as 48 solar panels, which make the house generate more electricity than it consumes in the summer. (Image courtesy of Farr Associates.)
Farr has been in business for almost 30 years, designing buildings with Leadership in Energy and Environmental Design (LEED)certification. LEED standards—such as conserving water, planting native landscape, specifying paint low in volatile organic compounds—are now so routine in the Farr office that the team focuses more on energy usage and carbon footprint. To do so, the firm relies on the Passive House Institute US (PHIUS) standard.
A diagram of the YannellHouse and its various green features. (Image courtesy of Farr Associates.)
“PHIUS is a very aggressive energy efficiency standard for buildings,” explained Doug Farr, founding principal and president of Farr Associates.“It sets a maximum energy use intensity per capita. It’s really aggressive and [passive houses are] really hard to do. That’s what we started doing with every project we can get away with.”
V-shaped butterfly roofs help to collect rainwater, which is directed to an underground cistern for use in irrigation. (Image courtesy of Farr Associates.)
Farr Associates sets a goal of making every building passive with the aim of attaining net-zero energy. Farr said that his firm can’t achieve that level even a third of the time, but that it guides them toward designing buildings that are as efficient as possible. The passive house standard of PHIUS emphasizes insulation and high-performance windows—virtually eliminating thermal bridging and infiltration from the outside. This ultimately requires much less energy to maintain interior comfort in a structure.
As Farr and his team were conducting research for the recently released book Sustainable Nation, he made observations regarding the use of natural gas to heat homes. “In the past, we’ve been very proud if we reduce energy use in a building by half or 60 percent, but then we would continue to heat the buildings with natural gas,” Farr said. “We would have made a dent on slowing down climate change and introducing GHGs in the air, but when we’d choose to heat with gas in the end, we kind of blew it. The insight I gained writing Sustainable Nation is that what we really want to be doing is stranding the carbon underground. The buildings we use, the vehicles we drive, the grid that we rely on—all of those things need to be carbon free.”
In addition to designing buildings, Farr Associates participates in urban planning. When asked how to layout an urban environment in a sustainable fashion, Farr explained that, first, the city’s planners have to have their priorities in order: focusing first on pedestrians, then bikes, then public transit, and finally private automobiles.
By focusing first on pedestrians, it’s possible to ensure that people in the city will prefer to walk than to drive, ultimately using less energy. To do so, it’s necessary to create small blocks because, according to Farr, pedestrians like to make decisions about the directions they’re going to take.
An illustration of the master plan for Colony Park in Austin, Tex., which was adopted by the city in 2014. The plan designates the park as a walkable residential area with commercial sections, and includes “efficient building design, water conservation strategies, and zero-waste technologies,” according to Farr Associates. (Image courtesy of Farr Associates.)
When deploying passive solar heating, orientation of buildings also matters, but only for small buildings like single-family homes. Surprisingly, Farr said that large buildings tend to be more energy efficient, due to a higher ratio of exterior surface area to interior volume of the building. However, monotonous large buildings are often less engaging to pedestrians than smaller, fine-grained buildings. This is one reason that Sustainable Nation sets the optimal height of a city at about 8 stories.
Farr is also in favor of flexible, distributed electricity, likely using solar power. “Distributed energy is the idea that each building would ideally generateall of the power it needs,” Farr explained. This method has a number of benefits, ranging from reliability and scalability to flexibility and efficiency.
Farr Associates’ portrait of a city in which sustainability is placed at the center of urban planning. (Image courtesy of Farr Associates.)
“What we see in the future is designing buildings to assume that there are all-electric vehicles that get plugged into the garage, whether in the building itself or a separate free-standing facility,” Farr explained. “The batteries in the cars may well be the thing that gets the main building through the night and winter. Thinking about where the electricity comes from, it could be on the roof or it could possibly be no farther than my garage to charge my car.”
The Role of BIM and Climate Change
Given the widespread nature of building information modeling (BIM) in AEC, it makes sense that the software is being increasingly used for sustainability purposes, including for energy management and even a building’s carbon emissions.
A team of researchers based in Canada and Hong Kong conducted a 2016 study into the use of carbon estimating methods within BIM to create real-time, spatial representations of carbon emissions data within a building. Focusing on the carbon footprint of a residential building during the operating stage of its lifecycle, the study’s authors analyzed the carbon dioxide emissions associated with electricity and natural gas usage. This information was then fed back into Autodesk Revit to create a graphical representation of carbon emissions associated with particular areas of the building.
A simple BIM model representing carbon emissions of particular areas of a building based on electricity and natural gas usage. (Image courtesy of Mousa et al.)
In addition to using BIM to manage the environmental impact of a building, the software can be deployed for resiliency measures. As Autodesk and its partners begin to develop the area around the Eiffel Tower ahead of the 2024 Olympics, the company has demonstrated to the City of Paris some applications for BIM that relate to disaster preparedness.
Nicolas Mangon, Autodesk vice president of AEC Strategy & Marketing, said about his visit with the deputy mayor of Paris and the governor of the Paris region, “I showed them how they could use BIM to simulate flooding in the city, if, at some point, they need to evacuate the Louvre and save the Mona Lisa if it gets flooded.”
Other simulations that Mangon showed the city officials were how road closings would affect city traffic, how toxic aerosols might be dispersed during a terror attack, the structural integrity of the buildings and underground facilities, and the movement of people in the streets.
Canadian engineering ﬁrm SNC-Lavalin used CFD to better understand emissions from a blast furnace. (Image courtesy of SNC-Lavalin.)
Vice President of AEC at Dassault Systèmes Jerry Jackson pointed out, in many ways the efficiency that BIM and other tools bring to construction helps to reduce waste in the otherwise wasteful AEC industry.
“In the built environment, it all comes down to resources. The way we think about our mission within AEC as it relates to sustainability is to provide platform universes that can enable project outcomes that are far greater than the resources they require,” Jackson said.
Dassault Systèmes and other software developers boast the ability of cloud-based tools to unite the diverse group of stakeholders in a construction or urban planning project by providing a single location for project data in the cloud. Additionally, it’s often argued that preplanning the project via BIM can help reduce errors, waste and the time needed to construct the building.
CadMakers was able to connect remote stakeholders and model the Tallwood House building with accuracy to a tenth of a millimeter using CATIA and the 3DEXPERIENCE platform on the cloud. (Image courtesy of Dassault Systèmes.)
CadMakers used Design for Fabrication’s CATIA application from Dassault Systèmes’ 3DEXPERIENCE platform on the cloud to model the Tallwood House building with accuracy to a tenth of a millimeter. Within CATIA, the team was able to place and size spaces for pipes, shafts and cabling within clearance and spatial requirements. Many elements, including cross-laminated timber (CLT) panels and glued laminated timber, were constructed off-site, where quality could be more closely controlled. In this way, what would have typically been an unwieldy construction project became more like a highly controlled factory, according to Jackson.
Ultimately, the project was completed about three months ahead of schedule, highlighting the sort of material waste—and GHG emissions associated with it—that can be eliminated through efficiency on the design side of construction alone.
“A dataset that we understand really well is the rate that the U.S. has stopped smoking cigarettes. Now we’re at the rate we were in about the 1940s. One of the findings of Sustainable Nation was thatin Chicago, if we decarbonize the U.S. economy at the same rate of change that the U.S. stopped smoking cigarettes, we would miss our carbon targets by 125 years,” Farr said.“We would decarbonize by 2150 and that’s just way too slow.”
For its part, Farr Associates has initiated a campaign to spur AEC firms in Chicago to reduce their carbon footprint. Farr Associates is hoping to get 50 percent of Chicago members of the American Institute of Architects (AIA) to sign a pledge to track carbon and energy performance by the time that Greenbuild International Conference and Expo occurs in Chicago this November.
Lisa Dickson has a nuanced view of the future of the Earth, its climate and its inhabitants, in part due to her formal academic training as a paleontologist who studied mass and background extinctions. She separates the different possibilities into three major categories: a complete elastic recovery; plastic recovery, in which the environment might not be quite how it was before the industrial revolution; and brittle failure, in which a critical threshold is passed, and the community cannot recover.
Dickson believes that there will be examples of each of those types of recoveries throughout the ecosystem. Given our dependence on resources, our adaptive inflexibility, and the 50 or more years of carbon currently in the atmosphere, she said, “I think that we’re definitely testing our luck in terms of how far out we can push things before we start to get over that cliff and see less plastic deformation and more of a brittle break.”
Events such as Hurricanes Harvey, Maria and Katrina may temporarily grab the public’s attention and are expected to occur more frequently. “The question is how much does the system have to break before we step back and decide to fundamentally change,” Dickson said.
Farr framed his outlook in terms of emotion and action. “Instead of coming away from the research we did on Sustainable Nation with fear—fear of the unknown or fear of whether or not we’re going to make it—I came away with a different emotion: anger—anger at what I was seeing. Anger is something you can act on. Fear is not. Anger is highly motivating. I’m mad that the projection we turned out [was] that it would take 125 years to decarbonize. Them’s fighting words. That makes me mad. I think we can do a lot better.”