Are current building codes adequate for extreme weather?

Do current building codes adequately reflect knowledge gained from experience with recent storms and are the codes changing fast enough?


https://facilityexecutive.com/2015/12/are-current-building-codes-adequate-for-extreme-weather/
Do current building codes adequately reflect knowledge gained from experience with recent storms and are the codes changing fast enough?
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Question Of The Week: Are Current Building Codes Adequate For Extreme Weather?

Are current building codes adequate for extreme weather?

indoor air qualityDo current building codes adequately reflect knowledge gained from experience with recent storms and are the codes changing fast enough?

By Bhavesh Patel

Building codes are a compendium of standards designed to protect the health, safety, and welfare of people with respect to the construction and occupancy of buildings and structures. They provide minimum standards of design, construction, and quality of materials to safeguard occupants and property within.

Among the main codes applicable for commercial buildings in the United States are the International Building Code (IBC), a model building code developed by the International Code Council and adopted by many states, and the National Electrical Code (NEC).

The codes are composed of standards and suggestions that can, individually or in groups, be adopted or implemented by a local level of government (state, city, or municipality) with the intent to protect the public.

Updating of the codes is important to take advantage of not only new and evolving technology but also knowledge acquired since the previous edition.   

weather-building-codes
(Credit: Comstock)

The extreme weather events around the country in recent years have shown us how severe and widespread repercussions can be. For example, the high winds, driving rain, flooding, rising sea level, and other effects of Hurricane Sandy in late October 2012, impacted 24 states, with particularly heavy damage occurring in New York and New Jersey. Overall, more than 8 million utility customers lost electrical power. Damage exceeded $71 billion (based on the value of the dollar in 2013) and wreaked havoc on energy infrastructure at many facilities and in numerous communities. At several facilities, there was total loss of electrical power. And since then, there have been many events where extreme weather caused major disruption of business-as-usual at facilities lying in the wake.

Given what occurred around the country, have updated codes and standards been proactive enough to increase the likelihood that power for essential services or even all services could be expected to remain uninterrupted during and after a major event? 

While codes and standards governing installations of emergency backup power cannot be expected to cover every eventuality, updates and additions should reflect lessons learned from Hurricane Sandy and other recent major storms.

For instance, the NFPA 110: Standard for Emergency and Standby Power Systems, 2013 edition, Annex A, paragraph A.7.2.4 says, “EPSS (emergency power supply system) equipment should be located above known previous flooding elevations where possible.” And paragraph A7.2.5 goes on to state, “For natural conditions, EPSS design should consider the ‘100-year storm’ flooding level predicted by the Sea, Lake, and Overland Surges from Hurricanes (SLOSH) models for a Class A hurricane.”

The qualifiers in the two paragraphs – “where possible” and “should consider” – can dilute the effect of the code if the project specifiers are not strict and careful in determining what “possible” can entail. The words “where possible” and “should consider” are not as straightforward in conveying intent as a more emphatic “must” and leaves the door open for less sense of the need to comply.   

Here is another example: The NEC articles 700 and 701 address the capacity for emergency systems and legally required standby systems, respectively. They note that emergency generators have to handle all the critical loads but do not apply to the rest of the hospital, which, in light of extended interruption of normal power, might have to run on generators for extended periods. Therefore, sizing the generator sets according to codes may not be sufficient for a particularly severe weather event. 

Code changes should, and increasingly do, aim to minimize vulnerability of energy systems to disruption from extreme weather events.

As noted in FEMA’s Hurricane Sandy Recovery Fact Sheet #3, published 11/19/2014, FEMA’s Hurricane Sandy Mitigation Assessment Team (MAT) identified 47 recommended actions that are related to building codes and standards.

More than half of the actions have, as of this writing, been partially or fully enacted. 

For example, in New York City, the MAT recommended several improvements to the NYC Building Code for consistency with the National Flood insurance Program (NFIP). Among the recommendations:

  • Adding a “flood zone compliance special inspection” of work related to raising, lifting, elevating, or moving buildings and specifying requirements for construction documents needed for such special inspections (implemented).   
  • An amendment that requires dwellings and most commercial buildings to be elevated at least 2 feet above the base flood elevation (BFE). (endorsed)
  • Requirement that essential facilities be elevated or protected to the higher of the 500-year flood elevation or the elevation required by the American Society of Civil Engineers (ASCE) Standard 24, Flood Resistance Design and Construction. (endorsed)
  • For New York State, the MAT recommended revising the minimum elevation requirement for non-residential buildings to two feet above the BFE. (The New York State Hospital Code is considering revision to require elevation to 0.2% annual chance of a flood.)     

The Building Resiliency Task Force, convened in 2013 at the request of the City of New York, made several recommendations in its June 2013 report aimed at improving building resiliency and maximizing preparedness for future weather emergencies.

The task force put forth 33 proposals to better protect NYC residents from effects of a wide-reaching storm. These included: locating building equipment higher in buildings to avoid damage from floodwaters (implemented); installing sewage valves to prevent backflow into basements during rainstorms and floods (implemented); allowing installation of temporary flood barriers on sidewalks outside certain classes of buildings (implemented); natural gas generators for powering lighting, elevators, fire safety, and other building systems (implemented); quick connects for temporary generators and boilers (implemented). 

Another code change that hopefully will make a difference: in NYC, new hospital and nursing home buildings must include hookups that support quick connection to temporary generators and boilers. Existing buildings, however, have 20 years to comply.

The idea of what is considered 100-year storms in terms of the ability to inflict damage on people and property may have to be revised if communities are to adequately protect against them. For example, sand dunes built at beaches along the New Jersey coast after Hurricane Sandy did not stand up well against three days of battering rain and wind (a nor’easter) during late September/early October while Hurricane Joaquin tracked hundreds of miles east in the ocean. Resulting erosion created dangerous fall-off, requiring many beaches to close and await extensive replenishment of sand to recreate the dunes.

In light of the real-life frequency of intense storms and the repercussions they can bring, facility owners and tenants would benefit from clear and direct dictates in updated codes that spell out changes likely to promote greater resiliency.

weather-building-codesBhavesh S. Patel is vice president, global marketing for ASCO Power Technologies, a business of Emerson Network Power. He can be reached via e-mail at [email protected], or by calling 800-800-ASCO.

Question of the Week: Has your facility been impacted by extreme weather? What changes did you/would you make as a result? Please share your thoughts in the Comments section below.

 

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