47.5 MB - The Whole Building Design Guide

3.3 CRITICAL FACILITY DESIGNCONSIDERATIONS3.3.1 General Design ConsiderationsThe performance of critical facilities in past wind storms indicatesthat the most frequent and the most significant factor inthe disruption of the operations of these facilities has been thefailure of nonstructural building components. While acknowledgingthe importance of the structural systems, Chapter 3 emphasizesthe building envelope components and the nonstructural systems.According to the National Institute of Building Science (NIBS),the building envelope includes the below-grade basement wallsand foundation and floor slab (although these are generally consideredpart of the building’s structural system). The envelope includeseverything that separates the interior of a building from the outdoorenvironment, including the connection of all the nonstructuralelements to the building structure. The nonstructural systems includeall mechanical, electrical, electronic, communications, andlightning protection systems. Historically, damage to roof coveringsand rooftop equipment has been the leading cause ofbuilding performance problems during wind storms. Special considerationshould be given to the problem of water infiltrationthrough failed building envelope components, which can causesevere disruptions in the functioning of critical facilities.The key to enhanced wind performance is paying sufficient attentionto all phases of the construction process (including siteselection, design, and construction) and to post-occupancy maintenanceand repair.3-32 MAKING CRITICAL FACILITIES SAFE FROM High Wind