Tens of millions of square feet of commercial office buildings were built in Manhattan from the 1950s through early 1970s. Designed in an era when energy resources were cheaper, most were built with single-glazed curtain wall exteriors, a then-modern technology that promised more valuable office space. However, much of the building technology that enabled the development of these curtain-wall structures has been dramatically improved if not eclipsed outright. Many buildings of this era do not meet current code requirements for handicap accessibility, life safety, and wind loading. In addition to being energy inefficient, they are frequently unable to achieve higher office space ratings in the market despite being in prime real estate locations with proximity to transportation hubs. Pressure on New York City’s building stock to achieve higher efficiencies requires particular consideration of the building stock from this era.
The Midcentury (un)Modern study examines lifecycle energy and water tradeoffs in three scenarios applied to a case study building: properly maintaining these buildings; retrofitting these buildings to modern standards; and full replacement at higher floor area ratio (FAR). The results show that all three scenarios improve efficiency. Careful maintenance likely provides cost-effective but not significant performance improvements to the case study building, 675 Third Avenue. Deep retrofits, while theoretically resulting in dramatic improvements in energy performance, were unlikely to be financially viable. Full replacement with upzoning could result in a high-performance building would have nearly doubled occupancy and improved spatial quality, health, and safety while reducing overall energy use.