Oscillating Synergy: A Mid-Rise Office Tower on the High Line


Oscillating Synergy: A Mid-Rise Office Tower on the High Line


Juan Tejedor & Natasha Chamilakis
University of Pennsylvania


Franca Trubiano
University of Pennsylvania



This project stands out for its fantastical aesthetics and strong graphic capabilities. There is an impressive analysis of resources and a careful consideration of the envelope. It sparks a pertinent conversation about performance and parametrics. The design is energizing and inspiring for its attempt to provide a performative backbone to the geometric exercise of parametric design. The intention to derive the geometry by the desire to regulate light and solar gain should be lauded.


The environmental strategy for this building employs geometry as the primary tool in creating comfortable, well lit office environments. The building is split up into two semi-autonomous systems: a concrete core with sloping walls, and a set of structurally and environmentally independent steel “pods” that fit into the concavities of the undulating core. In the core, fresh air is funneled from the large operable windows through the angled walls into a central chimney where it is exhausted. This provides a constant source of fresh air. The pods, as thermally independent zones within the building regulate light and air through their double skin façade systems: each is equipped with an aluminum lattice that regulates visible transmittance and solar radiation. Depending on the season, the double skin cativity “atria” precondition incoming fresh air. The cavities act as air heating chambers in the winter months, using the sun to warm outside air as it travels into the offices. During summer months, the operable spandrels provide shade while allowing more fresh air to enter the pods and evacuate through upper corners of the pods. The pod geometries are shallow with slanted wall to encourage air circulation from top to bottom.

Situated in Chelsea, Manhattan adjacent to the high line, the building is fully integrated into a walkable, human scale neighborhood with ample access to alternative modes of transportation. With minimal parking and easy access to mass transit and bike routes, the building is eliminates the need for car trips. Entrances at the street and High Line levels encourage pedestrian interaction; shops inside the welcoming and ample lobby allow the building to integrate itself fully into the commercial strip along both 10th avenue and 18th and 19th streets. Public programming in the upper levels, including a theater and art gallery, integrates the building and its workers into the cultural activities of the Chelsea Gallery district nearby. With direct access to the high line, office workers are encouraged to travel away from their desks and spend their lunch hours along the park amenity.

Taking its cue from the High Line, the rooftop garden incorporates a large variation of trees, shrubs and plants that perform important functions such as absorbing excess water, providing shelter for local animal species such as birds, and attracting a wide range of insects, which include pollinators such as bees and butterflies. Raised wooden pathways that meander through these areas engage visitors while also protecting the flora from foot traffic. Many of the species on the garden are chosen for their practicality and sustainability; a majority of them are native to the Northeast and perform well under the seasonal conditions of this region.

Taking into account the climate of New York City, the building maximizes the use of passive design strategies where possible. An autonomous daylighting system which varies in density and openness based on the direction of each facade properly shades interior spaces at all times of the year. The building is designed to maximize passive ventilation where possible. Its massing also addresses the wide range of local temperatures through the integration of the concrete core, which buffers the thermal range, and the use of office “pods”, which allow for local climate regulation. LIGHT The intricate aluminum mesh facade has varying degrees of thickness (ranging from 1” to 4”) and density, which was calibrated according to results of daylighting shoebox tests. Attention was given to preserving views while optimizing daylight to minimize electric light use for every orientation.

The building’s water system relies for a large portion of its supply on captured rainwater, which is filtered inside a blue roof system integrated into the roof garden. Greywater then travels downward and supplies the toilets, meeting 60% of the building’s water needs. Municipal water supplies the sinks, but this water is then captured and fed into the toilet greywater system. Overflow during rainy months is fed into the municipal sewer system for treatment. In this manner, the building captures and manages 80% of its runoff and eases the burden on the New York storm water system.

The design employs daylight and ventilation as the primary means to heat cool and light the majority of office spaces, and as detailed in the included diagrams, reduce dependence on external energy. Additionally, rainwater accounts for nearly all of toilet usage, which accounts for 45% of water demand. Supplemental gas fired electricity generated on site supplements natural heating and cooling. New York State includes a significant portion of renewables in its energy mix; any non-renewable energy used by the building is purchased as carbon credits.

Building materials were selected to ensure longevity, durability, and minimal maintenance. The core was designed as a concrete structure because of its excellent thermal mass, which decreases the amount of energy needed to heat and cool interior spaces. Concrete is also locally produced and used, has low emissions of carbon dioxide, and maintains well in harsh weather. The office “pods” are composed of steel frames, low-e glazing, and ETFE insulation. The ETFE and steel are corrosion resistant, light weight, and flexible, while the low-e glass ensures that the interior remains warm in the winter and cool in the summer. The results of hygrothermal analyses of this construction indicate that the building assembly is resistant to the development of mold, ensuring both the longevity of the materials used in the building and the health of its occupants.

Flexibility is maximized through the modular design of the building. Although the “pods” are currently programmed as office spaces, they can be removed from the core for the purposes of modification, repair, and replacement. In addition to flexibility, the durable concrete and steel construction of this tower will allow it to last past the typical sixty year life of most buildings and evolve with the changing needs of shifting demographics.

The process of developing this project highlighted the importance of the connection between simulation and design. Models were created based on our observations about light and air, which were then tested in the simulation software. The feedback loop created between these tools enabled the project to be developed and calibrated in a more rigorous way than would have otherwise been possible. Thus, most important lesson derived from this project is the power of using scientific tools and analytical methods to measure design. The ability to interpret results derived from these tools is crucial, as is the ability to allow these results to inspire innovative design.