In the rush to recover from Hurricane Harvey, those of us along the Texas Gulf Coast are focused on repair and getting back to normal. However, we should take this opportunity of renewal to spend time to assess and prepare for future disasters. Whether repairing or building new, every project should use the many tools available to assess current and future risks and take steps to make our buildings more resistant to future shocks.
Resiliency has become the popular focus of sustainability recently in response to climate change accelerating, meteorological events becoming more severe and sea levels rising. Several recent initiatives have responded to this urgency of resilient design. The US Government issued Executive Order 13653: Preparing the U.S. for the Impacts of Climate Change that dictates all federal departments must develop plans for climate adaptation. The Department of Defense has quickly adopted the guidelines as the military often operates in areas with extreme climates and limited resources. The Rockefeller Foundation’s 100 Resilient Cities Initiative is placing Resiliency Officers in 100 cities throughout the world to deal with minimizing these impacts.
LEED introduced three new pilot credits in 2016 to address the need for lessening the impact of disasters on buildings. The pilot credits were developed in accordance with the Resilient Design Principles from the Resilient Design Institute. One overarching theme is that “diverse and redundant distributed systems are the most resilient”. A breakdown in one can be compensated for by another.
The pilot credits are currently being updated by USGBC and are not available online nor as a credit on a LEED project. But the process and tools are valuable resources for any project. I have summarized them here and list every tool used to inform the pilot credits in the links following the article.
IPpc98 Assessment & Planning for Resilience
The intent of this credit is to proactively plan for the impacts of disasters as well as long-term effects such as climate change. The first step is to assess the current risks to the project site using the assessment tools and the Assessment and Planning Workbook (link below). These can also include man-made threats such as terrorism, but the credit lists flooding (LEED uses the 500-year flood plain as a metric), hurricanes, tornados/high winds, earthquake, tsunami, drought, wildfire and landslides.
After identifying the top three current hazards for the project site, you must achieve one of the two following options:
Climate resistance planning is assessing the future vulnerabilities of the region to climate change regarding sea level rises, increased flooding, temperature and precipitation intensity. They encourage the use of local or regional studies if available. Also, use of the NOAA’s U.S. Climate Resilience Toolkit is recommended.
Emergency preparedness planning is evaluating the project’s emergency preparedness using the Red Cross 123 Assessment Forms and prepare a facility description form identifying those features of the building.
IPCpc99 Design for Enhanced Resilience
The intent of this credit is to create buildings that can resist the top three identified hazards in the risk assessment. This pilot credit offer options for almost all hazards. Option 1 is to implement mitigation strategies for each hazard-specific risk. For example, to address flooding, teams would follow ASCE 24-14 Flood Resistant Design provisions, place the lowest occupied floor five feet above FEMA Base Flood Elevation, follow FEMA 55 for MEP systems, foundations meet Coastal Zone V and sewer connections include backflow preventers. Earthquakes need to achieve a silver rating using the ARUP REDI rating system. Droughts need to reduce water use per LEED’s Water Use Reduction for Outdoor AND Indoor Water Use credits by at least 60%. Option 2 is to follow the FORTIFIED for Safer Business design criteria for the specific risks. This credit is a tremendous resource with numerous reference standards.
IPCpc100 Passive Survivability and Functionality During Emergencies
Your building has survived the initial hazard. This credit now ensures that the building “will maintain reasonable functionality in the event of an extended power outage or loss of heating fuel”. Functionality includes thermal comfort, access to potable water, and back-up power. The building should provide two of these three options. Habitable zones can be created that will serve the entire building population so the entire building does not have to meet these requirements.
Thermal resilience is a “livable temperature” for seven days in the typical extreme peak week of cooling and heating. Livable is by no means comfortable. For cooling in non-residential buildings, this would mean not exceeding 18 degrees F SET-days above 86 degrees F SET. Strategies to maintain this livability include natural ventilation (one of the issues that made New Orleans hospitals unlivable after Katrina), high-performance glazing systems, passive solar design, SHGC reduction and reflective roofs.
Back-up power is providing power for fuel-fired heating, fans, water pumps, lighting of 3 fc throughout the building with 30 fc every 500 sf, minimal plug loads, online access, and one elevator. Acceptable power sources are a generator with 72 hours of fuel (piped natural gas does not count), a solar system with 72 hours of battery storage, or a micro-grid.
Access to potable water requirements differ in municipal and rural locations. Access can be limited to water access only on lower floors. Pumps require back-up power or in-building storage of 2 gal per occupant per day.
Strategies from these pilot credits would be wise to consider in all buildings, considering so many of ours are built in vulnerable locations. What can we do to increase the likelihood that our buildings can serve the communities in their time of greatest need, whether that is directly assisting those in peril or accelerating a return to “normalcy”?
LEED Pilot Credit 98: Assess & Plan not available now
LEED Pilot Credit 99: Design not available now
LEED Pilot Credit 100: Survivability not available now
Rockefeller 100 Resilient Cities: 100
Building Green Resiliency Issues: Subscription access only
Resilient Design Principles: RDI
Red Cross Ready Rating: Ready
Executive Order 13653: 13653
DOD Sustainability: Plans
Assessment and Planning for Resilience
Use the resources below to fill out the Assessment and Planning Workbook
US Climate Resilience Toolkit: Toolkit
Flooding Risk: https://msc.fema.gov/portal/search Many areas of Houston are in the FEMA flood plain, especially along bayous.
Hurricane Risk: https://www.fema.gov/pdf/library/ism2_s1.pdf (page 6) Most of the Houston area is susceptible to Hurricane damage
Tornado Risk: https://www.fema.gov/pdf/library/ism2_s1.pdf (page 1) The Houston area is in Wind Zone III
Earthquake Risk: https://www.fema.gov/earthquake-hazard-maps Houston has no risk of earthquakes
https://www.fema.gov/media-library/assets/documents/15212 (for existing buildings)
Tsunami: https://pnsn.org/outreach/hazard-maps-and-scenarios/eq-hazard-maps/tsunami These maps only cover the pacific Northwest
Wildfire: https://community.fema.gov/hazard/wildfire-en_us/be-smart?lang=es The Houston area has moderate wildfire risk.
Drought: https://www.ncdc.noaa.gov/temp-and-precip/drought/historical-palmers/ This is an adjustable time-lapse map showing drought conditions back to 1900. Houston is susceptible to droughts.
Landslides: https://landslides.usgs.gov/hazards/nationalmap/ Houston has low risk of landslides
Houston Region Hurricane Evacuation Zones: http://www.h-gac.com/taq/hurricane/documents/2017-zip-zone-map.pdf Not part of the pilot credits, but vital information for our region.
Climate Resilience Planning: Vulnerabilities associated with climate change:
Sea Level Rise and Storm Surge: https://coast.noaa.gov/digitalcoast/tools/slr
River Flooding Projections: https://water.weather.gov/ahps/long_range.php
Winter Storms: https://www.fema.gov/media-library/assets/documents/98059
Temperature, Precipitation Changes and Storm Intensity: https://epa.maps.arcgis.com/apps/MapSeries/index.html?appid=3805293158d54846a29f750d63c6890e (U.S.)
Design for Enhanced Resilience
Multiple Risks: FORTIFIED for Safer Business Guidelines for resilient commercial properties: https://disastersafety.org/fortified/safer-business/
ACSE Flood Resistant Design (2014) Code must be purchased. Highlights here: https://www.fema.gov/media-library/assets/documents/14983
Executive Order 13690 Federal Flood Risk Management https://www.gpo.gov/fdsys/pkg/FR-2015-02-04/pdf/2015-02379.pdf
FEMA 55 Coastal Construction Manual: https://www.fema.gov/media-library/assets/documents/3293
Tornado/Hurricane: These resources vary on building type and wind zone. Refer to LEED Pilot Credit Design for Enhanced Resilience for guidance.
ASCE/SEI 7-10. All structures in wind zones II, III, IV: publications
FEMA P-361 Safe Rooms. Public use and multifamily in wind zones III or IV: https://www.fema.gov/media-library/assets/documents/3140
FEMA P-431 Safe Refuge. Non-community use in wind zones III or IV: https://www.fema.gov/media-library/assets/documents/2246
Earthquake: ARUP REDi Rating System: Earthquake Design: http://publications.arup.com/publications/r/redi_rating_system
National Tsunami Hazard Mitigation Program: http://nws.weather.gov/nthmp/documents/designingfortsunamis.pdf
FEMA P-646 Vertical Evacuation from Tsunamis: https://www.fema.gov/media-library/assets/documents/14708
ICC International Wildland Urban Interface Code: https://up.codes/viewer/general/int_wuic_2015
2013 NFPA 1144: http://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=1144
Drought: reduce both landscape and indoor (flush and flow fixtures) water use by 60%.
Landslides: Involve geotechnical engineers for all slopes greater that 15% of 6.75 degrees.
PASSIVE SURVIVABILITY AND FUNCTIONAILITY DURING EMERGENCIES
Refer to LEED Pilot Credit for specific details.
Thermal Resilience modeling guidance: http://www.resilientdesign.org/putting-thermal-resilience-in-the-leed-pilot-credits-to-the-test/