47.5 MB - The Whole Building Design Guide

With the advent of building codes requiringFor further information on designingglazing protection in wind-borne debrisglazing to resist blast, see the “Blastregions, a variety of shutter designs have enteredthe market. Shutters typically have aSafety” resource pages of the NationalInstitute of Building Sciences' Buildinglower initial cost than laminated glass. However,unless the shutter is permanentlyEnvelope Design Guide (www.wbdg.org/design/enve-lope.php).anchored to the building (e.g., an accordionshutter), storage space will be needed. Also,when a hurricane is forecast, costs will be incurred each time shuttersare installed and removed. The cost and difficulty of shutterdeployment and demobilization on upper-level glazing may beavoided by using motorized shutters, although laminated glassmay be a more economical solution. For further information onshutters, see Section 3.6.2.2.3.4.3.3 Non-Load-Bearing Walls, WallCoverings, and SoffitsFor buildings not constructed using concreteroof decks and concrete or CMU walls (asrecommended), shelters can be constructedwithin buildings for occupant protection.FEMA 320—Taking Shelter From theStorm: Building a Safe Room Inside YourHome (2004) describes how restroomsand storage rooms can be designed forsheltering inside new and existing buildings.It is recommended that wood-framed andpre-engineered metal buildings in areaswith a basic wind speed of 100 mph orgreater, that will be occupied during ahurricane, have a designated storageroom(s), office(s), or small conferenceroom(s) designed in accordance with FEMA320 to protect the occupants. AlthoughFEMA 320 is intended for residentialconstruction, the guidance is suitable forsmall shelters inside critical facilities such asfire and police stations. For large shelters,FEMA 361 criteria are recommended.In order to achieve enhanced missile resistanceof non-load-bearing exterior walls, thewall types discussed in Section 3.4.2 (i.e., reinforcedconcrete, or reinforced and fullygrouted CMU) are recommended.To minimize long-term problems with exteriorwall coverings and soffits, it is recommendedthat they be avoided to the maximum extentpossible. Exposed or painted reinforced concreteor CMU offers greater reliability (i.e.,they have no coverings that can blow off andbecome wind-borne debris).For all critical facilities located where thebasic wind speed is 100 mph or greater thatare not constructed using reinforced concreteor reinforced and fully grouted CMU(as is recommended in this manual), it is recommendedthat the wall system selected besufficient to resist complete penetration ofthe wall by the “E” missile specified in ASTME 1996.3-106 MAKING CRITICAL FACILITIES SAFE FROM High Wind