A STRONGER, MORE RESILIENT NEW YORK

1 a stronger , more RESILIENT NEW YORKC redit: Barry YanowitzCHAPTER 4 | BUILDINGS68 BuildingsA stronger , more RESILIENT NEW YORK691983 FIRMs 100-Year FloodplainSandy Inundation AreaComparison of 100-Year Floodplain in 1983 FIRMs and Sandy Inundation AreaBungalows in New Dorp Beach. Rowhousesin Sheepshead Bay. Office towers in LowerManhattan. Industrial warehouses alongthe waterfront in Sunset york Cityhas a diverse building stock encompassing approximately 1 million structures of almostevery imaginable type and combination of buildings are New york City s homes, workplaces, museums, historic landmarks, commu-nity centers, and places of worship and theyare also critical contributors to the rich and varied character of communities across the , because New york is a coastal city, itsbuildings have long been subject to climaterisks, particularly the flooding associated withstorm surge and sea level rise.

2 In fact, when theFederal Emergency Management Agency(FEMA) released its first Flood Insurance RateMaps (FIRMs) for New york City in 1983, it defined the 100-year floodplain the area thathas a 1 percent or greater chance of flooding inany given year as an expanse that today includes approximately 35,500 buildings withmore than 376 million square feet of these maps demonstrated the city s long-standing vulnerability to flooding, Sandyshowed that New york s buildings are evenmore vulnerable than previously s floodwaters inundated an area that included approximately 88,700 buildings, morethan half of which were located outside the1983 floodplain boundaries that were in effectwhen the storm arrived. These buildings encompassed roughly 662 million square feetof space and housed more than 443,000 resi-dents and 245,000 jobs.

3 (See map: Comparisonof 100-Year Floodplain in 1983 FIRMs andSandy Inundation Area) Sandy s impact is illustrative of the city s grow-ing climate risks. For example, the 100-yearfloodplain, defined on recent Preliminary WorkMaps (PWMs) created by FEMA, now encom-passes more than 67,700 buildings, nearlytwice the number of buildings in the 1983 FIRMs. In addition to the risks that the PWMs in-dicate these buildings now face, many of theseproperties also will be subject to significantnew Federal flood insurance requirements. However, even the revised FEMA flood maps donot reflect the full risk to New york City s build-ing stock. That is because these maps arebased on historical storm profiles and do nottake into account potential changes in coastalstorms or projected sea level rise, which, basedon recent high end projections for sea level rise,could expand the size of the city s floodplain toinclude more than 88,000 buildings by the2020s and more than 114,000 buildings by the2050s (see Chapter 2, Climate Analysis).

4 Theyalso do not take into account other risks thatclimate change could exacerbate, includingstorm-related wind protection measures are a significantand critical part of the City s efforts to protectbuildings from current and future climate risks(see Chapter 3, Coastal Protection). While thesemeasures should reduce the effects of stormsurge, destructive waves, and sea level rise, theywill not eliminate completely those impactsunder all potential storm conditions, and theyalso will take time to design, fund, and , they address only part of the challenge fac-ing New york City s building stock. It is thereforeequally important to supplement coastal protection measures by pursuing resiliency atthe building level, offering multiple approachesto protect a wide range of the city s structuresagainst the full spectrum of climate risks. That is why this chapter proposes a two-partstrategy for the city s building stock that is inkeeping with the overarching goals of this report to reduce the impacts of climatechange, while also enabling the city to bounceback quickly when such impacts are felt.

5 Thetwo-part strategy seeks to strengthen newSource: FEMA MOTF 11/6 Hindcast surge extentCHAPTER 4 | BUILDINGS70and rebuilt structures to meet the highest avail-able standards and to facilitate the retrofittingof as many existing buildings as possible so thatthey become significantly more RESILIENT thanthey are today. This approach will benefit a fullrange of buildings those that are and may become vulnerable; those that are new and preexisting; those that are residential and non-residential; those that were impacted bySandy and those that were not. How the Building System WorksAny understanding of the vulnerabilities of New york s buildings must start with an under-standing of the types of structures in the cityand how they are Characteristics and Uses of NewYork City s Building Stock New york City s buildings can be categorized bythe following attributes, all of which are relevantfor resiliency: physical characteristics; building use; and building age.

6 (See photos: Common Building Types AcrossNew york City)New york s buildings can be categorized bybuilding height, construction type (as definedby the Building Code), and proximity to otherstructures. Building height ranges from low-rise(1 or 2 floors) to mid-rise (3 to 6 floors) to high-rise (7 floors and up). Meanwhile, there aretwo main construction types: so-called com-bustible buildings that are built using lighterstud-frame construction or wood joists on ma-sonry bearing walls; and non-combustible buildings that use steel or masonry and concrete frames. Buildings in New york also canbe characterized by their proximity to eachother: they can be detached (freestanding);semi-attached (sharing a wall with anotherbuilding); or attached (sharing walls on at leasttwo sides with adjoining buildings).(See table:Categorization of New york City Buildings byPhysical Characteristics)Finally, buildings in New york also can be categorized by their age.

7 This is a key factor because it correlates to the rules applicable atthe time of the building s construction andtherefore the type of construction used. Ever since Peter Stuyvesant instituted the firstbuilding regulations in New york in 1648 (ap-pointing fire wardens to inspect buildings for firehazards), the City s regulations governing theconstruction and the location of buildings haveevolved, ensuring that new buildings meet Common Building Types Across New york CityAttached 1- and 2-Family HomeDetached 1- and 2-Family HomeLow- to Mid-Rise Mixed-Use BuildingHigh-Rise Commercial BuildingHigh-Rise Multi-Family BuildingLow- to Mid-Rise Commercial BuildingBuilding Height Low-rise: 1 or 2 floors Mid-rise: 3 to 6 floors High-rise: 7 floors and upConstruction Type(as defined by the Building Code) Combustible buildings: built using lighter, stud-frameconstruction; or wood joists on masonry bearing walls Non-combustible buildings: built using steel, or masonry and concrete framesProximity Detached: freestanding Semi-attached: sharing a wall with another building Attached: sharing walls on both sides with adjoining buildingsCategorization of New york City Buildings by Physical Characteristics Credit: Alexandros WashburnCredit: John Hans LeeCredit: DOB/Samantha ModellCredit: Wikimedia/Beyond My KenCredit: DCPC redit: Wikimedia/Jim HendersonCredit: DOB/Samantha ModellLow- to Mid-Rise Industrial BuildingA stronger , more RESILIENT NEW YORK71increasingly high safety standards.

8 While thisapproach has improved building safety overtime, the corollary of this is that many olderstructures in the city were built according to codes that leave them more vulnerable to extreme weather events than buildings con-structed to more modern Framework for New YorkCity s Building Stock Buildings in New york City are governed by awide variety of rules and regulations. Two Cityagencies share primary responsibility for over-seeing New york s buildings: the Department ofBuildings (DOB) and the Department of CityPlanning (DCP).DOB regulates construction standards to ensure safe and lawful building use. DOB ac-complishes its mission by enforcing severalcodes and regulations, including the City s Con-struction Codes (of which the Building Code isa part), the Electrical Code, and the Zoning Res-olution. DOB also is responsible for enforcingthe New york State Multiple Dwelling Law,which governs the habitability of multi-familybuildings in New york City.

9 DCP, meanwhile, establishes citywide regula-tions for building use, density, and bulk throughthe Zoning Resolution. DCP also initiates plan-ning and zoning changes for individual neigh-borhoods and business districts to promote theorderly growth and development of the changes to the Zoning Resolution initiatedby DCP require the approval of the City PlanningCommission and the City addition to DOB and DCP, many other Cityagencies play critical roles in overseeing NewYork s building stock. These include the Fire De-partment of New york (FDNY), the Departmentof Housing Preservation and Development(HPD), and the Board of Standards and Appeals(BSA). (See table: City Agencies That RegulateNew york s Building Stock)Thanks to the efforts of these agencies and oth-ers, New york has a long history of working toimprove the resiliency of its buildings. For example, the building codes and land use lawsenacted in the 1960s (including a new ZoningResolution passed in 1961 as well as criticalbuilding code revisions that culminated in anew Building Code in 1968) contained manymeasures that, while not explicitly designed toprotect buildings from climate risks, did seek to make buildings generally safer, and thus alsohad the effect of improving flood protection.

10 As larger buildings continued to be constructedto accommodate the city s growing population,the City amended its Building Code to increasefire protection requirements in areas with highconcentrations of residents. This resulted inheavier buildings that were constructed of non-combustible materials such as steel, concrete, and masonry materials that also re-duced vulnerability to structural damage duringstorm surge and flooding events. Over time,older, light-frame buildings in central portionsof the city tended to be replaced by bigger,heavier buildings, while light-frame, low-densitybuildings remained more common on theedges of the City began actively and deliberately incor-porating resiliency into its building regulationsin 1983, when FEMA first released its FIRMs forNew york City, which set the boundaries of the100-year floodplain (see Chapter 2).