By Luke Carothers

Completed in the Spring of 2023, 555 Greenwich is a 16-story office building in New York City that has been drawing attention for its new “circular energy infrastructure” approach to sustainability.  The developer is Hudson Square Properties who tapped consulting engineers JB&B and sustainable design firm COOKFOX to develop and implement practices shared from the Nordic market by Swedish firm urbs.  The result of these partnerships is the most sustainable office tower in New York City.  555 Greenwich also ranks among the most efficient commercial properties nationally.  Unique in its design, the structure at 555 Greenwich was designed to fit seamlessly with neighboring 345 Hudson.  To create a building with such a profound impact on sustainability,  the project team’s approach focused not on individual technological components, but instead on integrating wholly reimagined systems throughout the entire building including DOAS/Geothermal/Radiant Heating, Electrified Energy, and Artificial Intelligence Integration.

The project at 555 Greenwich occupies a space with a history that stretches back four centuries to when Trinity Church Wall Street received land from the Queen of England within the Hudson Square neighborhood of New York City–just north of Tribeca and adjacent to the West Village.  For much of the time since then, this space was occupied by farmland until several large buildings were constructed within the space to house a printing press district.  In 2017, the decision was made to convert the space into commercial office buildings and partner with the Norges Bank.  Around this time, Hines was brought onto the project as a small equity partner; the firm was also the asset and development managers, responsible for concept, property management, and  asset management and engineering.  According to Ben Rodney, Vice President at Hines and ESG Leader for their East Region, the 555 Greenwich project is representative of a paradigm shift in building design in New York City, especially in terms of carbon and sustainability.

For Hines and the teams working on the 555 Greenwich project, the question became whether to build “the best old building, or the first of the new generation of structures in New York,” says Rodney.  Ultimately, the decision was made to build the latter, which was influenced by partner Norges Bank who maintains a mandate to invest globally in sustainable design solutions.  Furthermore, within this mandate to invest globally is to invest in projects that are leading the market.  According to Rodney, this partnership also introduced project teams to AEC professionals from Nordic countries like Sweden and Denmark.  This gave the team working on 555 Greenwich the chance to learn from the kinds of structures that were being built in Nordic countries, many of which didn’t rely on fossil fuel or natural gas infrastructure while being in cold climates.  These structures often rely on energy transfer and storage as well as distributed heat and cooling.  With this perspective, Rodney says the team began thinking about how those concepts could be applied to a building in New York City.  He describes this step in the design process as “starting from a clean slate.”

To imagine these concepts in New York City, the design team worked with four different architects and an architecture competition to settle on a design for the building.  A key part of choosing a design for the building was utilizing the structure’s thermal mass.  This would allow the building to heat and cool itself and occupants.  Rodney says that to achieve this the team relied on using radiant slabs, which meant running tubing within a topping slab to circulate water and add or remove heat as needed.  Another major part of this innovative design was connecting the two buildings structurally, which would allow them to create larger floor plates.  To avoid settlement in the new building, Rodney says the team ended up having to dig down to the bedrock.  Digging these 120-foot caissons allowed the team to install a geothermal well system by running the system vertically along the caissons.  These geothermal wells connect to thermoactive slabs, which are in turn connected to air-source heat pumps on the roof and water-source heat pumps within the building for domestic water to create a circular energy infrastructure.

Although substantial completion of the 555 Greenwich project has concluded, there are still questions that will need to be answered, stemming from the systems that make it such a unique building.  Rodney says that there will be ongoing challenges in fine-tuning the building’s systems to accommodate for balancing these systems with what tenants want.  This includes not only explaining to tenants the differences from a traditional structure, but also “finding the right energy balance with the geothermal and radiant slabs,” according to Rodney, who further notes that the, “balance will change over time, making this an ongoing process.”  The process of finding the right energy balance for these systems can be considered a calculated risk, but its significance in positively challenging the current paradigm for structures in the United States is poised to overcome any challenges in finding this balance moving forward.