The challenges of adapting the vast inventory of existing critical buildings to withstand the effects of extreme climate events are distinct from the relatively easier task of designing new structures for resiliency.<
INTRODUCTION
With substantial parts of the New York City metro area’s power grid down and with Superstorm Sandy’s floodwaters disabling emergency power, at least 4 major NYC hospitals (Bellevue, Coney Island, Manhattan VA, and NYU Langone) were forced to evacuate all patients and to completely shut down. Coler at the north end of Roosevelt Island transferred some patients to its sister Goldwater at the south. The same level of vulnerability took down four major data centers supporting the telecommunications networks in Lower Manhattan. A police station was abandoned when it flooded and a wall collapsed. In Brooklyn and Queens, 29 nursing homes were severely damaged; despite receiving instructions to shelter their populations in place, they were unprepared to endure the storm and its desolating aftermath. Individual buildings, as well as city- and region-wide systems, were also unready. They still are.<
Building owners have a four-fold responsibility when climate-driven disasters strike:<
- Protecting occupants and users from death, injury, and suffering;
- Avoiding the evacuation of occupants if possible;
- Protecting buildings and their contents from damage;
- Ensuring that buildings can operate during and after the event.
Current building technologies offer the ability to construct new buildings and retrofit existing ones to better withstand the anticipated impacts of climate change. However, the challenges of adapting the vast inventory of existing buildings to those standards are distinct from the relatively easier task of designing new structures for resiliency. There exists a vast body of technical standards that can be put in place, or adapted for the local situation as it is coming to be understood. But a sobering aspect of the new paradigm is the rapid increase in dangerous conditions, such as rising sea levels and more powerful storms, as well as the ever-deepening science of the likely effects of climate change. Building standards and disaster planning will need to be revisited and updated frequently.<
KEY CONCEPTS AND FINDINGS
Owners of all commercial and institutional buildings—existing, in construction or planned—can begin now on a four-part process to meet their responsibilities in response to climate disasters. Owners should:<
- Conduct vulnerability assessments of their buildings in anticipation of the likely effects of extreme climate events;
- Identify the specific technical standards their buildings must meet, and the technologies and products available to do so;
- Update operational plans to keep their buildings working during disasters, and to quickly recover functionality afterwards;
- Create implementation plans to put in place the remedial actions indicated by the three preceding steps.
Assessing Vulnerability
First, the specific impacts buildings might experience during climate-driven disasters should be determined. The potential effects on a given location can be inferred from published flood-zone and wind maps, as well as historical and modeled future weather data. As noted in the Introduction, however, the increasing severity of recent and anticipated climate events reveals much existing data to be inadequate, and highlights an urgent need to update and reach consensus on such standards.<
Second, the critical roles of specific buildings should be established. A building, or a portion of one, should be considered a critical facility if it is required to withstand the effects of a disaster and remain in operation, whether to safeguard the activity conducted within it, or the lives and wellbeing of its occupants, other disaster victims, or emergency-services personnel. Critical facilities include, for example, hospitals, police and fire stations, data centers, evacuation shelters, and buildings or portions of buildings that provide essential support to them. Other vulnerable buildings should be required to withstand a climate disaster without failure of structural components, including façade elements, though they need not remain functioning and are likely to be evacuated during the disaster; these should be considered protected facilities rather than critical.<
Third, survey building systems. Essential building systems comprise the design features, technologies, and equipment necessary to support continued operations. For critical facilities, for example, these include emergency power systems, water and ventilation systems, vertical transportation systems, and food storage and preparation facilities. For critical facilities, the survey should assess the ability of essential building systems to continue functioning during a disaster. For protected facilities, the survey should evaluate the ability of the building structure and façade to survive intact.<
Meeting Updated Technical Standards
Two building components—structure/facades and internal systems—are key to resisting climate-driven threats whether from flooding, wind, snow, or extreme temperatures. Simply put, the goal is to assure that a building’s physical structure remains intact and relatively undamaged by the forces of a disaster, especially the structural system and the building envelope, including fenestration.<
Façade and structure: Current New York City and State codes specifying design requirements for snow resistance and flood resistance do not require changes. For wind load design, however, requirements should be upgraded to ASCE/SEI 7-10; this code provides ultimate wind-speed values and introduces maps that incorporate the risk categories. For example, for Occupancy Category III and IV buildings, which include those posing a substantial hazard to human life in the event of failure, such as schools, hospitals, and critical facilities as defined above, this code requirement corresponds to wind speeds with only a 3% probability of being exceeded in 50 years.<
Systems: We studied a range of building system and utility issues, including the vulnerability points of electricity, IT, gas, water, and steam services as they enter a building; the location and protection of mechanical equipment; emergency equipment to provide for and back up supplies of water and power; fire alarm and firefighting systems; and elevators. We reviewed these in the context of three facility types—commercial and institutional; healthcare; and other mission-critical buildings—and for both new and existing structures. Examples of options for making these systems more resilient are shown here.<
In general, a new critical building must meet higher performance standards than a commercial building, since its services are to be available before, during, and after a climate-driven event; new critical buildings should comply fully with new standards. Existing buildings demand more flexibility in determining the best corrective action. A realistic approach for an existing building is generally a best-practice standard, with some latitude in offering equivalent solutions. In some cases for existing buildings, even those deemed critical in function, evacuation may be the only feasible action to permit compliance.<
Developing Operational Plans
While many New York City-area agencies and institutions have disaster plans in place, in general these need to be updated to reflect the increased risks our region is now understood to face. Moreover, disaster planning should always consider buildings and their particular vulnerabilities and requirements.<
Before An Event
Not all disasters can be foreseen, but for some—in particular, weather events—there may be substantial warning and the ability to anticipate specific effects like flooding. Building owners’ advance operational plans should address a range of issues, including the evacuation and relocation of occupants, building shutdowns, and the possible extended relocation of occupants afterwards. For critical facilities, emergency equipment and supplies should be accommodated, temporary relocations should be envisioned, and advance arrangements should be made with the NYC Office of Emergency Management for disaster-zone access for essential personnel.<
During An Event
Planning should consider the provision of security for evacuated buildings; in Class E high-rise buildings, the risk of a fire-detection system failure requires particular attention. Hospitals by definition are both especially vulnerable and uniquely essential during disasters, and disaster planning for them creates distinct obligations. For example, hospitals should plan for surge capacity for emergency and inpatient departments, the capability to house and feed stranded staff, and provisions for “passive operational survivability,” such as natural ventilation during power failures and electric generation capabilities independent of the City’s grid.<
After An Event
Plans for continuing or resuming operations in the wake of a disaster should consider that normal transportation and supply routes will most likely be disrupted. Therefore, back-up supplies and the on-site storage capacity for them are necessary. Emergency-supply agreements made in advance with vendors may be advisable. Portable emergency trailers housing heating or electrical generators, water or oxygen supply, and sewage or waste containment may need to be accommodated as well.<
Clean-up and decontamination may require, for example, pre-negotiated arrangements with specialized contractors or vendors for mold removal, fuel or sewage overflows, debris removal, disposal of floodwater and the like, and environmental waivers for removing contaminated water and debris to disposal points. Restoration of normal operations may require post-storm inspections of floor and façade walls; testing and remediation of mechanical, electrical, plumbing, and communications systems; drying out of flooded areas; prioritizing of repairs and/or demolition; and even a strategy for abandonment or managed retreat, if a facility is found to be damaged beyond repair.<
Implementing a Plan
Determining A Building’s Risks, Strengths, and Weaknesses
Conducting a vulnerability assessment of a building and evaluating it against updated technical standards will indicate what must be done to make it disaster-ready. This process will also illuminate relative priorities among the risks a building faces and the available solutions, and create a sense of sequence for how to proceed.<
Calculating Available Resources
Implementation of a plan requires evaluating both capital and human resources. Capital resources could be funds from internal sources, such as operating budgets and borrowing; or from external sources, such as grants, tax incentives, and philanthropy. Human resources include the personnel who will be expected to follow the operational procedures developed for withstanding and recovering from an extreme event. They also include a building’s stakeholders who may be potential allies or opponents in preparedness planning.<
Reconciling Needs and Resources
Arriving at a realistic plan will mean reconciling needs with resources. Typically, needs outstrip resources, so that strategic trade-offs and deferments are necessary. These can be arrived at by:<
- Developing a detailed plan;
- Conducting cost-benefit analyses of its elements;
- Determining a timeframe and budget;
- Assembling a team responsible for implementation
Keeping On Track
A progress-monitoring system, and honest assessments of progress, should be part of establishing a building’s preparedness.
Deviations from a plan must be corrected. Standards may change, our understanding of the risks may change, and available funding may change, so periodic re-examination and re-calibration will be necessary. Intervals of four and eight years are realistic to stay up to date.<
POLICY CONSIDERATIONS AND REGULATORY IMPLICATIONS
Because vulnerability assessments are the necessary first step in making buildings resilient, and because no obstacles exist to undertaking them immediately, the City Council should enact a law requiring building owners to conduct vulnerability assessments of their properties.<
A great number of specific changes to current zoning and building codes will be called for if the City and its buildings are to withstand repeated climate-driven and other disasters. In general, these include:<
- An updated building code mandating a more robust disaster resistance capability for all new buildings.
- Hardening and retrofitting of existing buildings deemed vulnerable.
This will be expensive, and in some cases impossible. The building code should provide a mechanism for permitting non-compliance; in such cases, an alternative strategy of evacuation should be required. Critical-function buildings in vulnerable locations must have a plan for Transfer of Service to a protected alternate facility, and these alternate facilities should be required to have the additional capacity and equipment to accommodate such a transfer.<
Zoning for land-uses should appropriately align with new and updated knowledge of flood zones and other risks, which may mean downzoning in some areas; and revisions to zoning and density limits for other areas that may in the future be required to absorb growth previously destined for flood zones and vulnerable waterfronts.<
OPPORTUNITIES AND NEXT STEPS
Long Term<
Innovation in the development of disaster-resistant building design strategies, technologies, and materials is essential. Where applicable, such innovations that already exist or are being implemented in other countries where resiliency planning is more advanced should be adopted or adapted. New York City’s particular vulnerabilities call for:<
- Policies that move toward elimination of non-compliant existing buildings that cannot be hardened, and their replacement—with an exception path for buildings deemed of significant historic or cultural value.
- Regional protective systems that enhance, or eliminate the need for, individual building responses.
These should involve making utility, data, and security networks redundant and resilient, and finding regional strategies for maintaining essential services and supplies, such as public transport, food, and fuel, during disasters. In particular, regional networks for maintaining essential healthcare services must be established.<
Medium Term
Numerous scientific, governmental, and professional organizations and collaboratives are exploring the potential impacts of climate change on natural and built environments; these include the Federal Emergency Management Agency, the National Academy of Sciences, the National Oceanic and Atmospheric Administration, the U.S. Conference of Mayors, C40 Cities Climate Leadership Group, and many others. The specific challenges that extreme climate events pose for buildings, cities, and in particular for densely populated areas, illuminated by our experience of Sandy and explored by this and other initiatives in the storm’s aftermath, must be brought to the attention of these research bodies. The goals should include:<
- Better simulation models of water
- and wind behavior on built structures;
- New national reference code for building construction;
- Zoning and planning approaches that bring patterns of development into line with present and emerging knowledge of disaster-prone areas.
Short Term
Advisory bodies have been established at the City and state levels, and among professional associations, to develop recommendations for changes to codes and zoning, façade and structural systems, building systems, and operational requirements. Similar groups focused on disaster-response planning will also have recommendations relevant to the design and operation of buildings. Their valuable findings will need to be aligned and reconciled. In the meantime, building owners should begin assessment programs to determine their risks; undertake voluntary upgrades to their properties; and update operational plans for disaster events.<
A collaborative, integrated design approach to assessing and upgrading critical and commercial buildings will enable these important facilities to remain in operation when we most need them.<
APPENDIXES
Below are additional reports and appendices by individual working groups, individuals and organizations who are part of the Post-Sandy team. They are posted as submitted by the authors and have not undergone review or rewriting by the editorial team.<
Critical & Commercial Reference Materials<
CRITICAL & COMMERCIAL BUILDINGS WORKING GROUP
Co-chairs:
Paul Bello, PE
William Sarama, AIA
Raymond Skorupa, AIA
Joseph Tortorella, PE<
Committee:
Antoine AbiDargham, PE
Rich Cohen, PE
John Decina, AIA
Paresh Doshi, PE, LEED AP
Mostafa Elmorsi, SE, PE
Robin Guenther, FAIA, LEED AP
Jason Harper, AIA, LEED AP
Jonathan Michaeli, PE, LEED AP BD+C
Jonathan Miller, AIA
John Oswarek, PE,
Erin Peavy, Assoc. AIA, LEED AP BD+C, EDAC
Ferhat Salah
Sheldon Steiner, PE
Israel Wertentheil
Emily Zwettler, Assoc. AIA, LEED AP<
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