NYC Accepts the Challenge to Convert Modern Office Buildings

Can “Location, Location, Location” Make Alterations Economically Viable?

As widely anticipated, the Office Adaptive Reuse Task Force made recommendations in January 2023 that included the expansion of the applicability of conversion tools to both a larger geographic area and to newer buildings. But even if all the recommendations are enacted, what challenges would remain to foster more office-to-residential conversions?

Expansion of Existing Conversion Tools

While residential use is allowed as-of-right in most commercial zoning districts, most commercial-to-residential conversions have required a relaxation of regulations governing windows for light and air by the Zoning Resolution’s Article I, Chapter 5  (“ZR 15-00") and Section 277 of the New York State Multiple Dwelling Law (“MDL”).  Essentially, where the typical residential standard requires 30 feet from a window to a lot line or opposite building wall, ZR 15-00 requires 15 feet – and sometimes as little as 5 feet in certain circumstances.  Because most office buildings’ interior-facing windows don’t open onto a 30-foot yard or court, expanding the applicability of these provisions is important but, in many cases, not sufficient – especially as the focus shifts to newer office buildings with deep, repetitive floor plates which often lack interior-facing windows altogether. 

As expected, the task force has proposed to lower the age requirement so that ZR 15-00 would apply to office buildings constructed before December 31, 1990, in all high intensity office districts (i.e., C4, C5 and C6 districts). Currently, ZR 15-00 is only applicable to (i) pre-1961 buildings in Manhattan below 60^th Street and older parts of Brooklyn and Queens and (ii) pre-1977 buildings in the Financial District (Lower Manhattan south of Murray Street). 

Deep Floorplates

As we pointed out this past December, post-1961 midtown office buildings typically contain very deep floor plates – often two times the depth of an office building in the Financial District. This is mainly attributable to two factors: (i) the Financial District was developed on smaller blocks that are not part of the street grid and (ii) Financial District buildings are generally older and contain multiple setbacks above certain heights.  Whereas a Midtown office building has been constructed on a through lot since 1961, it is permitted to cover the entirety of the lot - no yard, court or open area of any kind is required, and a resultant conversion may be overly dependent on street-facing windows for means of light and air.  While ZR 15-00 is effective in relaxing requirements for open spaces upon which windows open on to, it does not address the middle of the floorplate – in some cases 50 to 100 feet away from any window.  Thus, residential conversions of Midtown’s post-1961 office buildings may prove to be more costly than in Lower Manhattan as space in the middle of a deep floor plate either becomes underutilized or necessitates removal with the creation of a new interior court.

Inoperable Windows

While ZR 15-00 relaxes requirements for the location of windows, it does not relax the residential requirement to open such windows.  Due to safety concerns and for the efficiency of central HVAC systems, office buildings constructed after 1961 typically do not have operable windows.  However, Building Code Section 1203.4.1.2 requires that all residential habitable spaces be provided with natural ventilation. While the NYC Department of Buildings may have to ability to vary this section for conversions under MDL 277.16, it has not been done to date. This means that some or all the windows may need to be replaced with operable windows – a costly endeavor as window replacement may also necessitate a recladding of the existing curtain wall.  SOCOTEC's existing building wall experts have provided solutions during building re-positioning projects where window replacement was key to the project's aesthetic and functionality goals.  So it is possible, but may increase the cost of the conversion.

Example: 180 Water Street and Its Implications for Midtown

180 Water Street was the only example of a conversion of a post-1961 office building cited by the recommendations. Constructed in 1971 and converted to residential use in 2015 (during a more favorable economic time than today), this project was able to apply ZR 15-00 due to its location in the Financial District.  Nevertheless, while it was also advantaged by frontage on three streets, the design includes (i) a costly newly created 30’ x 40’ inner court taken from the center of an approximately 120’ x 170’ floor plate and (ii) the replacement of inoperable with operable windows.  This example illustrates that even when subject to the City’s most favorable regulations and other beneficial physical factors, extensive alterations were necessary to facilitate the conversion of office to residential use. 

Can Midtown Make it Economically Viable?

Given that post-1961 Midtown office buildings typically (i) contain floorplates deeper than 170 feet, (ii) may only front on one or two streets rather than three and (iii) have inoperable windows, future conversions of such buildings would need to command a favorable revenue stream to off-set the intensive alterations needed to make such a project economically viable.

Let us help you determine your prospects to convert. The synergies of Code, Zoning, Energy and Envelope can provide a road map.