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FEMA P-361, Safe Rooms for Tornadoes And Safe Rooms for Tornadoes and Hurricanes Guidance for Community and Residential Safe Rooms FEMA P-361, Third Edition / March 2015 All illustrations in this document were created by FEMA or a FEMA contractor unless otherwise noted. All photographs in this document are public domain or taken by FEMA or a FEMA contractor, unless otherwise noted. Portions of this publication reproduce excerpts from the 2014 ICC/NSSA Standard for the Design and Construction of Storm Shelters (ICC 500), International Code Council, Inc., Washington, D.C. Reproduced with permission. All rights reserved. www.iccsafe.org Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of FEMA. Additionally, neither FEMA nor any of its employees makes any warrantee, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, product, or process included in this publication. Users of information contained in this publication assume all liability arising from such use. Safe Rooms for Tornadoes and Hurricanes Guidance for Community and Residential Safe Rooms FEMA P-361, Third Edition / March 2015 Preface ederal Emergency Management Agency (FEMA) publications presenting design and construction guidance for both residential and community safe rooms have been available since 1998. Since that time, thousands Fof safe rooms have been built, and a growing number of these safe rooms have already saved lives in actual events. There has not been a single reported failure of a safe room constructed to FEMA criteria. Nevertheless, FEMA has modified its Recommended Criteria as a result of post-disaster investigations into the performance of safe rooms and storm shelters after tornadoes and hurricanes. Further, FEMA’s changes also consider the 2014 update to the consensus standard from the International Code Council® (ICC®) and the National Storm Shelter Association (NSSA®), the ICC/NSSA Standard for the Design and Construction of Storm Shelters (ICC 500). This third edition of FEMA P-361 presents updated and refined criteria for safe rooms compared to the second edition’s 2008 criteria. The criteria presented in this publication address how to design and construct a safe room that provides near-absolute protection from wind and wind-borne debris for occupants. FEMA continues to support the development of consensus codes and standards that establish minimum acceptable requirements for the design and construction of hazard-resistant buildings. FEMA also supported and participated in the development of the original ICC 500 and the 2014 edition. Although the ICC 500 took much of what was presented in the first edition of FEMA P-361 and updated and codified it through the consensus standard process, some differences remain between the two documents. The differences between criteria are described at the beginning of each chapter of Part B of this publication. There are also differences in scope; for example, FEMA P-361 includes emergency management considerations and risk assessment commentary that are beyond the scope of ICC 500. When safe room designers, operators, and emergency managers implement FEMA’s Recommended Criteria in their projects, they can feel confident that they are using the best available information to guide the design and construction of a safe room (public or private) that provides near-absolute protection from the deadly winds and wind-borne debris associated with extreme-wind events. Additionally, if the safe room is being constructed with FEMA grant funds, adherence to the FEMA Recommended Criteria described in Part B of this publication is required. Safe Rooms for Tornadoes and Hurricanes i Guidance for Community and Residential Safe Rooms Table of Contents Preface ................................................................................................................................................................................... i Introduction to FEMA P-361 .............................................................................................................................................. xi Part A A1 . Purpose and Background ........................................................................................................................................A1-1 A1.1 Purpose .......................................................................................................................................A1-2 A1.2 Background on FEMA Safe Room Design History and ICC Code Development .................A1-3 A1.2.1 Development of FEMA Safe Room Guidance ..............................................................A1-3 A1.2.2 Development of ICC 500 ................................................................................................A1-4 A1.2.3 ICC 500 Comparison with FEMA P-361 .......................................................................A1-4 A1.2.4 FEMA Safe Room Grant Funding Program .................................................................A1-5 A1.3 Safe Room Terminology ............................................................................................................A1-5 A1.3.1 Terminology ...................................................................................................................A1-6 A1.3.2 Types of Safe Rooms ......................................................................................................A1-7 A1.4 Deciding Whether to Install a Safe Room ................................................................................A1-8 A2 . Extreme-Wind Risk Assessment and Analysis.........................................................................................................A2-1 A2.1 Risk Assessment ..........................................................................................................................A2-2 A2.1.1 Assessing Threat .............................................................................................................A2-2 A2.1.2 Assessing Vulnerability ..................................................................................................A2-9 A2.2 Risk Analysis .............................................................................................................................A2-11 A2.2.1 Analyzing Risk ..............................................................................................................A2-11 A2.2.2 Considering Multi-Hazards in Safe Room Design.....................................................A2-11 Safe Rooms for Tornadoes and Hurricanes iii Guidance for Community and Residential Safe Rooms A3 . Costs and Benefit-Cost Analysis .............................................................................................................................. A3-1 A3.1 Safe Room Costs .........................................................................................................................A3-1 A3.1.1 Design Parameters That Affect Safe Room Costs ........................................................A3-1 A3.1.2 Cost and Size Data from Constructed and Proposed Safe Room Projects ............... A3-3 A3.1.3 New Construction versus Retrofit ................................................................................ A3-3 A3.1.4 Cost of Hurricane Community Safe Room versus Combined Tornado and Hurricane Community Safe Room .............................................................................. A3-4 A3.2 Benefit-Cost Analysis ................................................................................................................. A3-4 A3.2.1 Benefit-Cost Analysis Software ..................................................................................... A3-4 A3.2.2 Determining Project Benefits ....................................................................................... A3-5 A4 . Operation and Maintenance Considerations for Community Safe Rooms .........................................................A4-1 A4.1 Safe Room O&M Plan Objectives and Parameters ..................................................................A4-2 A4.1.1 Safe Room Design ..........................................................................................................A4-2 A4.1.2 Multi-Use versus Single-Use...........................................................................................A4-2 A4.1.3 Duration of Occupancy .................................................................................................A4-3 A4.1.4 Intended Occupants ......................................................................................................A4-4 A4.2 Staffing and Personnel Considerations ....................................................................................A4-5 A4.2.1 Roles and Responsibilities .............................................................................................A4-5 A4.2.2 Contact Lists ...................................................................................................................A4-5 A4.2.3 Staff Training .................................................................................................................A4-6 A4.2.4 Work Shifts......................................................................................................................A4-7 A4.3 Community Outreach and Notification ...................................................................................A4-7 A4.3.1 Identifying Potential Safe Room Occupant
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