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Adopted Rules: Closed to Comments

Adopted Rules Content: 

 

 

Statement of Basis and Purpose

 

This rule is promulgated pursuant to the authority of the Commissioner of Buildings under Sections 643 and 1043 of the New York City Charter and Section 28-103.19 of the Administrative Code of the City of New York.

 

The current reference standard American Society of Civil Engineers CUAScE·) 24, as modified by Section BC G501.1 of the New York City Building Code, does not mandate freeboard above the Base Flood Elevation ("BFE") for buildings in Structural Occupancy Category I or II. As per Section BC G201.2 of the New York City Building Code, the BFE is the elevation of a flood that has a 1-percent chance of being equaled or exceeded in any given year.

 

This rule amends this reference standard so as to require freeboard of up to two feet for these categories of buildings, depending on the type of building and the type of flood risk.

 

As defined in the regulations of the Federal Emergency Management Agency relating to the National Flood Insurance Program, 44 C.F.R. 59.1, the term "freeboard• is a way to represent a measure of safety concerning flooding, usually expressed in feet above a flood level for purposes of flood management. Freeboard requires a building to be elevated higher than the BFE. Freeboard aims to compensate for the many unknown factors that could contribute to flood heights greater than the floods predicted for a particular area, such as waves, bridge openings, and the effect that development has on ground water absorption.

 

In accordance with Table 1-1 of ASCE 24, as modified by Section BC G501.1, buildings in Structural Occupancy Category I or II include the majority of new construction in New York City, including 1- and 2-family dwellings, apartment houses, retail stores, and office buildings.

 

This rule requires freeboard of up to two feet for new, substantially damaged or substantially improved buildings that are located in areas of special flood hazard. The rule brings the New York City Building Code into alignment with the latest edition of New York State Uniform Fire Prevention and Building Code (2010) by requiring two feet of freeboard for 1- and 2-family dwellings, and into alignment with the latest edition of ASCE 24 (2005) by requiring one or two feet of freeboard for other Structural Occupancy Category 11 buildings and for Structural Occupancy Category I buildings with certain flood risks.

 

This rule will result in new construction and substantial improvements that exceed the BFE, preventing loss of life, property and business interruption in cases of flooding.

 

 

Effective Date: 
Fri, 05/31/2013