For the last few years, it seems that resiliency and resilient design have become the buzzwords for the architectural community. From a panel at the last year’s AIA convention to an institute based on its principles, it seems that everyone is talking about resilient design.
So, what is resilient design and how does metal architecture and construction play into it? Metal Architecture took the opportunity to talk to a few leaders in the resilient design community and find out.
Metal Architecture: What is resilient design and how important is this concept to your practice?
Alex Wilson, president of the Resilient Design Institute, Brattleboro, Vt.: Resilient design is a process of creating buildings and communities that will not only be safer in a world of increasing risks and vulnerabilities, but also better adapted to what are likely to be changing conditions with the advent of climate change. Relative to my long-term focus on sustainability, resilient design provides a motivation to create buildings that are more sustainable. With resilient design, for example, we may create highly energy-efficient buildings that will maintain habitable conditions in the event of an extended power outage-those buildings will keep occupants safe, but they will also minimize environmental impacts.
Rachel Minnery, LEED AP, director, built environment policy for the American Institute of Architects, Washington, D.C.: Resilient design recognizes that our world is an interconnected, changing place. Design is a systems-based problem-solving tool. Resilient design strives for environmental, social and economic sustainability with the ability to adapt to known and unknown risks and vulnerabilities. Negative impacts are reduced now and in the future by the choices we make.
Greg Mella, FAIA, LEED AP BD+C,
vice president at SmithGroupJJR, Washington, D.C.: Resiliency is a companion to sustainability. While sustainability seeks to maintain our balance with the environment, resiliency seeks to maintain the durability and integrity of our communities by designing with consideration to the changing landscape that results from climate change. This concept is significant because we want to create enduring architecture. To do so requires us to anticipate the future, as well as the increasing likelihood of disruptions to our communities. Resiliency principles are increasingly informing our practice so that we may create buildings that stand the test of time and provide value to the communities of which they are a part.
Robin Guenther, FAIA, LEED Fellow, principal, Perkins+Will, New York City: Simply put, resilience is the capacity of a system to handle disturbance but still retain its function and structure. It’s a concept that originated in the study of ecological systems, and why some ecosystems survive while others collapse when confronted with the same disruption. Since its origins in the 1970s, resilience thinking has been extended to buildings.
Most recently, to a building’s ability to withstand the challenges of extreme weather. Given the increasing incidences of extreme weather globally and the extensive property damage and, in some instances, loss of life, the concept of climate resilience is extremely important to the design and maintenance of our built environments.
Jeffrey Dugan, AIA, principal at Dattner Architects, New York City: Resilient design really became a high priority for all architects and engineers here in New York City post-Superstorm Sandy. While other parts of the country and places around the globe have experienced similar storms and the accumulative effects of climate change, Hurricane Irene and the subsequent Superstorm Sandy one year later really opened our eyes to the impact of climate change in New York and the northeast seaboard. Since most of our work is in the public realm we have always considered resiliency in design. Building design and material selection for public buildings must be resilient not only to resist the forces of nature but also to accept the intensity of use. Longer building life is a more sustainable built environment, i.e. resiliency = sustainability.
MA: What are some things you have to keep in mind when designing a resilient building?
Minnery: You have to keep in mind not just the direct impacts of design choices, but the impacts of the impacts. Qualities that contribute to a resilient building include durability, flexibility, adaptability and redundancy. Consider the sourcing of materials and natural resources-are they renewing at a rate that is equal to or greater than their use?
Wilson: It’s important to remember that we’re not just designing in response to the last natural disaster-whether a hurricane or tornado or storm surge-we’re designing for a range of future disasters. There is a tendency to focus only on the sort of event that happened most recently. With resilient design, we should keep in mind a whole range of natural and anthropogenic (human-caused) disasters.
Guenther: Extreme weather challenges current practice in a number of ways: the sheer scope and magnitude of weather events-coastal flooding, wind speeds, heat and/or cold waves-is now exceeding the design thresholds that buildings were designed for. The frequency of these events is increasing. We have come to increasingly rely on aging municipal infrastructure, such as power grids, levees or equivalent flood control measures, which are aging and more prone to failure, so that critical buildings NEED to be able to operate regardless of these failures.
I think we need to consider providing building level power infrastructure, and we need to equip buildings to be more passively survivable-meaning, we need to minimize the risks of overheating or freezing that may occur if mechanical systems fail-by designing well insulated envelopes that are appropriately shaded, and include operable windows.
Dugan: Buildings are always designed with context in mind. Environmental factors such as flood plains and seismic zones have distinct impacts to building design with respect to decisions about architecture, structure, building systems and site/civil design. Proximity factors such as adjacencies to man-made structures like vehicular roadways or naturally occurring saltwater bodies also inform our decisionmaking process. The building program and use are equally important. These basic guiding principles existed before any recognition of the importance of resiliency and the broader acceptance of climate change. The key is to continue to ask questions during the design process to better understand context, program and function relative to the level of resiliency to incorporate into a building.
Mella: For projects in low-lying areas and in proximity to the shoreline, we consider the potential impacts to sea level rise, modeling both conservative and worst-case scenarios. The Chesapeake Bay Foundation’s Brock Environmental Center [in Virginia Beach, Va.] sits within the flood plain near the shores of the Lynnhaven River. The building is set back from the shoreline and sits 14 feet above sea level. We recognized that with sea level rise, storm surges that ordinarily would leave the site dry now have the potential to flood the entire site at higher and higher flood elevations.
Another important consideration is the concept of being self-sustaining if a project’s infrastructure is disrupted. In this regard, resiliency pairs well with net-zero energy and water buildings. If municipally provided power and water is lost, the Brock Center can still function, relying on natural daylighting for illumination and natural ventilation for cooling. Its super-insulated envelope allows it to maintain thermal conditions for an extended period of time. Its collected rainwater can continue to meet the occupants’ potable water needs. Its two wind turbines and 38 kW photovoltaic array can still generate power, powering emergency lighting and ventilation. If additional batteries were provided to take the center “off-the-grid,” the center could function very much like it does on a typical day in the face of most disruptions, thus weathering the storms we anticipate in the future.
MA: How can metal building products work in resilient designs?
Minnery: Metal is a strong, durable and malleable product. Certain applications of metal can be easily recycled and reused.
Guenther: Certainly, metal building products have a major role to play in the development of fixed and movable external shading systems that help buildings manage heat gain and loss. Metal roof and wall panel systems can be engineered to withstand high winds, uplift and water penetration in wind-driven rain events. Insulated metal panel systems can provide high levels of thermal insulation as we continue to drive down energy consumption.
Mella: The Brock Center sits within a hurricane zone and its design anticipates many “doomsday scenarios” like crashing waves at its foundation, high-winds twisting the building’s structure, and large and small wind-borne debris crashing into the building’s windows and skin. Steel structural components and reinforcing provided a means to efficiently resist these forces, armoring the design. Beyond metal’s strength, we used metal products for their durability as well. Zinc shingles clad the building’s roofs and were selected for their corrosion resistance and ability to withstand the harsh coastal climate and saltwater spray. Aluminum cladding on the exterior windows ensures these vital elements to the design are enduring and low-maintenance. Metal roofs also proved to be the ideal substrate for the project’s rainwater collection and renewable energy installation. Photovoltaic panels clip to the building’s standing seam roofs without penetrating the exterior envelope. The metal roof and gutters provide an impervious, stable, and smooth surface for collecting and channeling rainwater without promoting the growth of algae.
Wilson: Well-built metal buildings offer some inherent benefits over wood-frame buildings when it comes to storm and flood resilience, but they also offer some challenges. The increased thermal bridging through metal framing in exterior walls, if not addressed with a continuous layer of rigid insulation, can result in lower energy performance, and that could make such buildings less effective at maintaining habitable conditions during power outages or interruptions in heating fuel-and, thus, less resilient. Resilient design takes careful thought, no matter what the building system.
Dugan: Metal building products have always played key roles in the resiliency of building design. Steel or aluminum flood barriers are good solutions for existing structures as typical designs are easily customizable for their applications. Metal building panels provide cost-effective resilient building envelope solutions for many building types. Special metal alloys provide critical protection when building components are proposed for use in proximity to saltwater bodies or to roadways where deciding agents are used. Assembly design and material selection are the two primary factors in the quality of resilient metal building products.
MA: What are some benefits of using metal products in resilient design?
Minnery: When designing for reuse, architectural components can be disassembled and reassembled for flexibility and adaptability. Recycling and reuse reduces waste.
Guenther: Because metal products are inherently fire resistive and strong, metal products will play a greater role in developing solutions for increasing extreme weather. Metal products in wet, coastal regions subject to flooding may be a great choice-ecologically advanced corrosion resistant coatings will need to be developed.
Also, the fact that metal products are among the most successfully recycled building material feedstocks will continue to underpin the development of a broad range of affordable, high-performance products with lower embodied energy.
Dugan: An example is the materiality of a metal product: stainless steel and aluminum alloys provide quality resilient sustainable choices for many building products including bollards, handrails, hardware, doors, windows, building cladding and roofing. Protection, longevity, flexibility, efficiency and cost are the main benefits of metal products in resilient applications.
Wilson: Metal roofing and siding sheds rain and snow extremely well, minimizing risk of moisture damage and decay. Metal framing cannot rot, so if it gets wet it can dry out without lasting damage and without harboring mold or other decay organisms. Metal roofs provide the best option for harvesting rainwater-which can be an important resilience measure, particularly in areas prone to drought. Metal siding and roofing protects buildings from wildfire.
MA: Generally speaking, how does resilient design differ across the nation? Are there regional characteristics that need to be taken into account?
Minnery: Communities across the nation face both common and differing risks, threats and vulnerabilities. Climate and culture will inform design choices.
Guenther: Absolutely. Climate resilience measures in coastal regions, where high winds, rising sea levels and storm surge inundate coastal areas with saltwater more frequently, are totally different from the desert southwest where arid winds drive forest fires that threaten buildings. In the Midwest, high winds, tornadoes and hail storms drive a totally different set of performance requirements for buildings-mechanical fastenings that prevent building elements from becoming projectiles take precedence, as does impact-resistant exterior systems.
In the 2014 fires in Southern California, Palomar-Pomerado Hospital [in Poway, Calif.] cited its metal and glass façade as a significant reason that it could “shelter in place” when fires approached within a mile of the building.
Mella: Resilient considerations are often regional in nature. Take for instance rainfall and future droughts. Changes to regional rainfall patterns are quite evident over the past few years, seeing states like California experiencing historic droughts. Some regions are getting wetter while others are getting dryer, necessitating new regional approaches to core sustainability concepts like stormwater management, xeriscaping and rainwater collection.
The consideration of buildings that function during power losses is also driving architecture to embrace bioclimatic design strategies and passive design, relying on vernacular approaches that shaped architecture long before the availability of cheap, reliable power. An office building in the Southwest should look substantially different from one in the Northeast. Resilient architecture can never be a one-size-fits-all solution.
Wilson: The vulnerabilities faced by buildings and communities differ widely by region. In low-lying coastal areas, storm surge, fueled by storms, is often the greatest risk-and one that will be exacerbated in coming decades with rising sea levels. In the Midwest, tornadoes are often the greatest risk. In California and select other regions, earthquakes are a major concern. California, as we have seen in recent years, is also vulnerable to drought-as are many other regions, even some surprising places like Atlanta as we saw in 2007 and early 2008. Wildfire is a threat in certain Western, drought-prone areas. And some urban areas are perhaps most
vulnerable to terrorist actions that would cause power outages, interruptions in heating fuel and other problems.
Resilient design responds to these vulnerabilities in different ways. FireWise construction practices are far different from wet flood proofing or seismic design, but all are aspects of resilient design.
Dugan: Absolutely. Context is everything, almost. Environmental conditions such as weather and pollution have an impact on the durability of buildings. Proximity to naturally occurring elements such as saltwater bodies relative to corrosion; rivers and deltas relative to flooding; mountains, cliffs and hillsides relative to flash flooding and avalanches; forests and prairies relative to brush fires, deserts relative to extreme weather; volcanoes and seismic faults relative to movement of the earth’s crust; as well as proximity to man-made impacts such as roadways, factories and refineries among others that produce by-products that can impact the durability of structures.
MA: How do resilient design concepts in buildings differ between residential and commercial?
Minnery: The economic and emotional investment is very different and thus the appetite for risk will vary. The building size, use, location and occupancy all play a part.
Wilson: Many of the issues are the same or similar, while others differ significantly. For one thing, residential buildings are lived in, so the issue of maintaining habitable conditions in the event of lost power is extremely important, while commercial buildings can more easily be evacuated. At the macro scale, mixed-use buildings
(residential on upper floors, retail and commercial on lower floors) offer some important benefits relative to density and access to services; these areas will do better in the event of a gasoline shortage or an inability to pump gasoline because they are more walkable, an issue we saw with Superstorm Sandy in 2012.
Mella: Resilient residential buildings can be designed to be self-sustaining to weather the storm, providing safety and comfort for its occupants. Essentially, a residential building will maintain its function during disruptions. A commercial building can be tasked with doing more. An office building may not need to function like an office building during a catastrophic event, instead it might provide shelter for its local community. Commercial buildings may be more dynamic, acting as community centers, providing for those in less-resilient environments during disruptive events.
Guenther: We want residential occupants to be able to shelter in place in their homes during and/or following extreme weather events-so we want the buildings to suffer little to no significant damage and be occupiable with or without municipal utility systems. The more insulated and climate responsive residential buildings are, the better they will be in these instances. New York City, where high-rise construction is common, is strengthening codes requiring operable windows to prevent overheating and ensure adequate ventilation air (as well as emergency power for vertical transportation systems). In commercial buildings, the priority is to prevent damage that will render the building unusable following an event. That means envelopes that don’t fail.
Dugan: Commercial developments may be able to justify a higher level of resiliency than say single-family residential due to the opportunity for a continued return on investment at the commercial level.
Multifamily projects may incorporate a higher level of resiliency than single family as the development itself may be managed by the developer who has a stake in producing a building that is more resilient and more sustainable. Decisions about these levels of resilience above any local code requirements would be made at the outset of the design process and continue to be refined through construction largely due to cost and commitment to the design intent.
MA: How are building programs and assessment tools helping the move toward resilient construction?
Guenther: A new nonprofit called the Resilient Design Institute has developed strong resilient design principles that must begin to inform assessment tools and policies. The insurance industry is really acting as the great leveler of construction standards, which are otherwise locally promulgated and can be highly variable. The new Fortified Standard by the Insurance Institute for Building and Home Safety (IBHS) is interesting.
The federal government is also developing guidance documents-the Climate Resilience Toolkit just launched (toolkit.climate.gov) promises to consolidate a really terrific set of case studies and best practices across all sectors of the economy, ranging from agriculture to buildings. I’ve been working with the Department of Health and Human Services on a resilience toolkit for health care, which will be integrated early next year with the larger toolkit.
Mella: The Resilient Design Institute was formed in 2013 to help promote principles and solutions that allow communities to function and thrive during disruptive events. The Institute has defined 10 principles that illustrate what resilient buildings and ommunities do, and its website catalogues resilient strategies at a building, community, and regional scale.
Wilson: Some green building rating systems, such as the LEED Rating System, are benefiting the transition towards resilience by encouraging higher levels of energy efficiency. Others, like the Living Building Challenge go further, with not only energy, but also water and access to emergency power. In the next few years, special rating system overlays or separate resilience rating systems are likely to emerge.
As for assessment tools, energy modeling tools do a pretty good job at predicting performance, but most do not model what happens to interior conditions in the event of lost power or heat. I would hope to see some improvements with such tools in the coming years. There are some very good resources today for assessing flood risk, with the Federal Energy Management Agency
(FEMA) taking the lead. The IBHS offers excellent guidance on certain aspects of resilience through its Fortified Home and Fortified Business programs.
Minnery: Building programs serve as a guide for making positive design choices. Assessment tools allow a certain level of modeling some results of potential design strategies, thereby increasing the comfort level of implementation.
Dugan: I feel that we have, and architects in general have, always used the program and the design process to infuse buildings with resiliency. Perhaps the most important result of this current focus on resiliency, like the trend towards sustainability is the significance that is placed on this subject in the dialogue between the client and the architect during design. Prior to the recent trends towards resiliency or sustainability, due to cost impacts, it was very difficult to convince clients of the importance of designing with these things in mind.
MA: How are building codes taking resilient design into consideration?
Guenther: New York City, post-Sandy, conducted a significant study on performance of varying typologies of residential and commercial buildings based on loss of grid utilities and have recognized the need to continue to mandate even better thermal performance. They also developed a series of building code revisions (beyond IBC) to improve resilience, from requiring vertical transportation on emergency power to backflow prevention to enhanced water resistance of building materials in flood zones.
Dugan: As our context changes, so do our building codes. In New York this is a direct recognition of climate change. While building codes most notably in Florida have addressed issues of flood and hurricanes, New York is now making similar adjustments for more stringent regulation of how buildings are constructed in coastal flood prone areas. Flood maps are being adjusted which in turn impact the area of application for certain building restrictions that are either already in the code or have been added in recent updates.
Minnery: Building codes are for fire and life safety, and while they strive for quality construction they are not written to protect from property damage. Locating a building properly is the first and often most critical component of resilient design.
Wilson: Energy codes help to improve resilience, but they could go further. I would like to see building codes address the habitability of buildings that lose power or heating fuel-ensuring that they don’t get too hot in the warmer months or too cold in the winter. This aspect of resilience is a life-safety issue, just like fire and earthquake resistance; it’s not just a matter of saving energy or protecting the environment. Building codes could also govern the use of building materials in flood-prone locations-mandating the use of materials can get wet and then dry out without requiring replacement or harboring mold.
*Photos of Coney Island Commons and Spaulding Rehabilitation Hospital by Anton Grassl/Esto, courtesy of Perkins+Will.
*Brock Center Photo/Illustration courtesy of SmithGroupJJR.