Upgrading the Mechanical Systems in Louis Kahn’s Richards Building


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By Matthew S. Chalifoux, AIA, Principal
EYP Architecture and Engineering, Washington, DC

Louis I. Kahn’s Alfred Newton Richards Medical Research Laboratory (Richards Building) at the University of Pennsylvania holds a unique place in the history of 20th century culture as one of the most influential buildings of the post-war era. Designed 1957-58 and completed in 1961, the Richards Building received international attention for its design before it was even completed, garnering a solo exhibition of the design at the Museum of Modern Art in New York, but its considerable functional shortcomings have been the target of much venom for over fifty years.

In 2008 the Richards Building was nominated for and granted status as a National Historic Landmark (NHL), and with this came a mandate to develop a reuse approach that would improve the functionality of the building without compromising its unique and innovative architectural and engineering expression. At the same time the University took a critical step in rethinking the building program to accommodate dry lab space for the Center for Cognitive Neuroscience. Designed by Kahn to accommodate wet labs and animal facilities the technical requirements of these spaces were always at odds with Kahn’s plan and spatial design. The overlay of systems, while carefully orchestrated in the original design had been augmented in the ensuing years to provide for upgraded technology, resulting in a tangled web of piping, conduit and ductwork that were a significant visual distraction. By shifting to dry labs the systems requirements would be significantly reduced even with the significant power and data requirements.

In 2010 the University hired a team led by EYP Architecture and Engineering to develop an overall plan for the upgrades to the building and to implement a partial renovation of two of the four building towers (Towers C and D). The mandate was to develop a renovation model that would meet the programmatic and functional needs of the scientists, improve the energy efficiency of the building in keeping with the University’s campus wide climate commitment and be sensitive to Kahn’s design for the Richards Building.

 Richards Building from the south, 1965 (Penn Architectural Archives)

Over the years much has been written about the Richards Building, focusing primarily on the plan layout, Kahn’s “servant” and “served” spaces, the studio like lab spaces created with the Vierendeel truss system and the beautifully detailed exterior envelope. While the success of the current project was certainly going to be judged by how these elements were treated, a significant part of the original design and a linchpin of the renovation design solution was the building systems, particularly the mechanical systems. The remarkable story of Kahn’s partnership with structural engineer August Komendant in the development of the Vierendeel truss system, a dominant feature of both the interior lab spaces and the exterior envelope, has been well told. An equal partner in the original design was mechanical engineer Fred Dubin.

The obvious architectural links between the systems and the architectural design are the outside air intakes, or “Schnorkels”, located on the south facade of the service tower and the exhaust shafts located on each of the lab towers. Kahn utilized these system requirements to develop the iconic profile of the building. But the systems layout also influenced the interior layout of the service tower, the size of the lab spaces and the geometry of the Vierendeel trusses. The systems engineering team was an integrated part of the design development evidenced by early design sketches which show not just architecture and structure, but also duct and piping layouts.

EYP and Urban Engineers of Philadelphia proactively explored all options that would offer greater energy efficiency while also offering possible leeway in other aspects of the design, particularly the exterior envelope upgrades. The starting point for the team was the design standard for systems at the University, a variable air volume (VAV) system. The team also evaluated the use of chilled beams, which Penn was also exploring on a separate pilot project, so while there was familiarity with the system there was also a learning curve. Multiple options were studied for both the systems and the exterior glazing. While the most energy efficient model utilized chilled beams and insulated glazing units in new thermally broken frames, this would have meant removing the original bent, stainless steel frames which are a significant character defining feature of the original construction. Energy modeling showed, however, that the reduction in efficiency of a monolithic, laminated glazing system in the original frames was acceptable if chilled beams were used for interior cooling. By approving this holistic approach to the design the University acknowledged the importance of the exterior components, but challenged the team to develop a HVAC design that utilized radically different technology than the original while being visually compatible with Kahn and Dubin’s design.

The team was faced with three primary challenges in developing the new HVAC design.

 Typical lab space as found in 2010 (Andy Wong, EYP)

Routing from the central units to each floor

The original layout of the ductwork from the four air handling units in the penthouse, one for each tower, down through two shafts and out to each floor was both highly efficient in the use of space and beautifully integrated with the architecture. The size of the ductwork was significantly reduced in the new design with the change to a dry lab program and the use of chilled beams. At the same time the phased approach to the building renovation precluded the new design following the original routing. The team used Revit software to layout all of the systems to ensure that they fit properly and as a design visualization with the University. While the renovation now has two towers fed from a shaft location that previously fed just one, the combined ductwork, piping and conduit occupy a zone at the ceiling that is no greater than the original design.

Routing within the Vierendeel trusses in each lab space

A function of the Vierendeel trusses was to provide a horizontal zone within each lab space for the exposed routing of the building systems. Details in the original construction documents provided a clear system for laying out the ductwork, piping and conduit both in plan and section to develop a sense of clarity for the systems that paralleled the structural design. The new design, though significantly different than the 1960 systems honored the spirit of the original. Each component, ductwork, piping and conduit were assigned a specific vertical zone and laid out in plan to coordinate with the structural system, allowing each to read independently of the other. At the same time the systems were designed to provide a level of flexibility to accommodate multiple floor layouts with the objective of minimizing the amount of reworking of the systems required when a lab was remodeled.

 Original “streamlined” ductwork in the first floor lobby (Matt Chalifoux, EYP)

Appearance of the systems components

Every element that went into the building in the original construction was carefully thought through to the last detail, and this was certainly true for the systems. How light fixtures were placed within the structural grid, in plan and elevation, reinforced the horizontal datum of the bottom of the trusses. The ductwork, located in the zone above the lighting, was carefully crafted to be “streamlined”, a phrase that was actually used in the specification. This meant ductwork assembly using slip joints and flush fasteners (no gasketed connections) and suspended using threaded rods set back from the edge of the duct. The end result was a remarkably simple form that seemed to float through the structure. With the chilled beam system we were introducing new objects to the vocabulary of the space that required care in locating them to be certain that the system would be both visually appropriate and functional. A layered design of the new light fixtures and the chilled beams minimized the visual impact of the new components while honoring the original design intent.

The first phase of the renovation, two floors of towers C and D, was completed and occupied in the fall of 2015. The systems have been operational through the winter heating season and are now just approaching the summer cooling season. The visual impact of the renovation has received positive reviews from the local architectural press and has met with approval from the users. The team is working closely with the University to evaluate the performance of the building systems to determine if the projected energy modeling is supported by actual use.

 New lighting fixtures and chilled beam units in a corner bay (Copyright 2015- Esto Photographers, Ryan Rotham)


Mr. Chalifoux is a Senior Historic Preservation Expert with over 30 years of experience in the renovation and rehabilitation of historic buildings. While his projects have ranged in scale from house museums to state capitols they have all included the sensitive insertion of new technology and systems to provide appropriate levels of climate control, life safety and security while also being environmentally sensitive and sustainable. His projects have received local, state and national awards for design, historic preservation and construction.