CHALLENGES
The conversion of existing buildings to residential program is not new. New York City has seen waves of conversions over the years: Soho and its famous loft conversions, the Financial District following 9/11 and again after the closures of super storm Sandy, and now after COVID. Past conversions were driven by economic considerations to minimize changes to the base building envelope and structure. Legal light and air requirements drive apartment layout and are often not compatible with the deep lease spans typical in postwar office buildings (or Soho warehouse lofts). The resulting apartment layout is either tailored towards a luxury product with double sized loft style rooms or towards a pack ‘em in shotgun style apartment approach where each unit is a skinny puzzle piece winding its way across the lease span in a 10 ft strip to reach its sole window. The extra depth of the lease span is used for walk through galley kitchens and awkward home offices which are often used dangerously as interior bedrooms with no access to light or air.
Floor Layout
New apartment buildings often follow the ~ 65ft deep double loaded corridor bar building typology with ~28ft deep apartments on either side of a central corridor. Office buildings often have 45-60ft lease spans (the distance between building core and façade). From an apartment layout point of view, an ideal conversion would entail stripping off the outer layer of the office lease span to bring the units into the efficient idealized range. This has historically been cost prohibitive.
Facade
The new climate regulations add an important new factor with improved energy efficiency requirements and reduced life-cycle carbon emissions. Many of today’s underutilized office buildings were built from 1950’s through 1980’s and have single pane glazing and poorly insulated facades at the end of their useful lives. It is now necessary to replace the building façade as part of these conversions which opens up the opportunity to find a balance between minimizing massing adjustments and optimizing quality apartment layouts. A new approach to conversions is therefore now viable whereby surgical adjustments to overall building massing can be made which drastically increase the quality of the apartment spaces. Floor area cut out at lower floors could be replaced with additional floors above if it can be cleverly arranged to fall within existing structural capacity or if structure below can be selectively strengthened to carry the extra floors.
Elevators
Office buildings require approximately twice as many elevators as residential buildings for similar floor area. Tall office buildings often have a zoned elevator approach where the low, mid, and high zone elevator banks run express from the lobby level to the zone of floors they serve. In an office building with three zones of elevators, it would be likely possible to likely eliminate one full zone of elevators. The existing elevators would need to be modified to stop at new floors and the old elevators would either be deconstructed and filled in or more likely simply closed up and lost as shaft space. An efficient conversion will need to consider where the elevator banks currently drop off and adjust the floor plan layout to take advantage of the extra leasable space. Should additional floors be added as part of a residential conversion, either a new elevator shaft and system will need to be installed to service the new floors or one of the old shafts would need to be extended, the elevator machine room relocated to new roof level, and the elevator ropes replaced for new lengths.
INITIATIVES
The building is situated at the intersection of Hell’s Kitchen – a predominantly residential neighborhood – to the west, New York’s Theater District to the south, the Midtown core to the east, and Central Park to the north. Like the Time Warner building – the approach is to embrace the complexity of these neighborhoods with a project that acknowledges that large sites in the center
of the city can and need to address many challenges simultaneously.
The addition of nearly 1,800 units of housing will help to support local businesses, activate streets and public spaces in the evening, and in that process create/nurture the kinds of amenities that office tenants are increasingly gravitating towards. Moreover, the market rationale for additional housing is clear with median rents in Manhattan climbing well past pre-pandemic levels. But it’s not simply enough to deliver housing production without consideration for the quality of the housing that is produced and the experience of the public realm.
The flight to quality in the office market is a reminder that cities like New York need to continue to deliver on the quality of the experience because that’s why people and companies are here. Our proposal is not a simple conversion of ‘office’ to ‘housing’ but a re-creation of an ambitious, dense, creative, and energetic community in a different form. This form is the new MIDTOWN GREEN, a mixed-use development including apartments with work-from-home layouts, office floors with outdoor space, community facilities, and retail, food and beverage. These uses are self-sustaining and contribute to the qualities of ambition, density, creativity, and energy that once characterized Midtown and remain as the guideposts for dreaming what it could become.
Converting extra deep Midtown office floor plates of the 1960’s to one which meets the legally required access to air and light for residential units is a geometric challenge. Many conversions have been done with Financial District office buildings but they tend to have their cores on the side and shallower floor plates than the monoliths of Midtown. Those buildings are often solved with an interior courtyard meeting the minimum requirements but offering compromised unit layouts. In addition, a building such as 1633 Broadway, at over 40 stories, does not lend itself to a central courtyard.
Our approach is to carve in from the outside and use the relieved structural capacity to build above. This load re-distribution approach facilitates unit layouts on the 25ft structural grid with generous yet not wasteful square footages as is found in Soho loft conversions. The apartment layouts take the NYC Dept. of Housing Preservation & Development design guidelines as the starting point and take advantage of the existing floor area to add comfortable work/study spaces. Internal core area that is unused due to elevator decommissioning or vertical zoning is converted to bicycle and tenant storage. The double-height mechanical floors that are no longer needed as a result of the decentralized HVAC system are converted to amenity spaces and access to terraces which result from stepping the building back as it rises. Lower floors are kept at their maximum possible build-outs (minimum carve-out) and are convertible between office and residential occupancies with an HVAC system that can accommodate both. The final result is an office-to-residential conversion without wasted floor area, many desirable corner units, and much added long-term value.
SUSTAINABILITY STRATEGY
Sustainability is fundamentally embedded in the project, from the reuse of most of the existing building to upgrading and electrifying outdated operational and systems. This proposal goes farther by integrating holistic sustainability strategies into the design. Sustainability here consists of five categories: Energy and Emissions, Embodied Carbon, Water, Indoor Environmental Quality, and Site and Landscape.
The project will include all-electric, energy efficient systems, a high-performance façade with integrated shading elements, material re-use and low carbon new structural components. Water will be conserved through low flow plumbing fixtures, potential water reuse between use types, and storm water management. The project will promote wellness through healthier materials, views to the city, and an optimized floor plate that affords optimal daylighting and potential for natural ventilation. The unique step back design offers multiple outdoor landscaped spaces, providing opportunities for native plant selections, pollinator garden species, and access to the outdoors for occupants deep in the heart of the city.
Living and working at Midtown Green will incorporate the best the city has to offer in terms of location and transit access, bringing a density back to midtown where existing services already exist. With the effective interventions, this proposal will bring a holistic sustainability and wellness vision to the office to residential typology.
