Fragment 05:

Union Station Bus Terminal

Who would have imagined ten years ago that inter-city bus travel would be as popular as it is today?  This document touches upon how the cache of American bus services is changing and with this change comes new demands on historical bus stations.  The consolidation of bus service in Washington DC fostered new program needs at historically prominent Union Station. Studio Twenty Seven Architecture’s solution responds to the constraints of the site and fulfills the requirements of the project brief, addressing the needs of the passenger population. But it also takes the project to a higher level. We used the project to raise questions about the nature of travel in the 21st Century. In the process we also developed an innovative method to build a geometrically challenging structure on a limited budget.  The result achieves Union Station’s desire for design excellence and it adds a new, small, but important icon within its walls.

Fragment is an episodic publication of Studio Twenty Seven Architecture. Each issue is dedicated to a singular idea, project, or element associated with the Art of Architecture published to foster future dialogues on architecture.

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Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Built in 1908, Washington DC’s Union Station is an icon of the turn of the 19th century and the golden age of rail transport. Today, with a new turn-of-the-century not far behind us, Union Station is as vital as ever, even as the city and its transportation infrastructure continue to evolve. Maintaining Union Station’s position as Washington DC’s preeminent transport hub requires that we welcome change. Maintaining its importance as an urban icon requires that we embrace architectural evolution, while respecting history. The Union Station intercity bus transit pavilions, opening this summer of 2013, met both these challenges.

Under the visionary leadership of Congresswoman Eleanor Holmes Norton, the Union Station Redevelopment Corporation (USRC), invited the nation’s intercity bus carriers to make Union Station their single point of embarkment in Washington. Previously, most carriers were disbursed around the city, dropping off and picking up from designated curbside spots that provided no shelter, amenities, or clear wayfinding for passengers. Bringing these operators into the Union Station fold would mean a better travelling experience for passengers, and clearer city streets for all.


Beverley Swaim-Staley
President & CEO
Union Station Redevelopment Corporation

Additionally, the new location within the Union Station garage complex would allow for easy connection with national, regional and metropolitan rail systems, as well as easier access to sightseeing buses, and shuttles servicing the capital’s universities. Union Station had already had remarkable success providing space for new urban transport models such as Zipcar and Car2Go car sharing, the Bikestation storage and repair facility, and Capital Bikeshare programs. It seemed a natural fit to embrace the increasingly popular intercity bus carriers as well.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

The only problem with bringing the buses to Union Station was the parking garage where the passengers would embark. The structure, an imposing concrete mass spanning a large portion of the rail yard, was purely utilitarian on the interior. There was no facility where passengers could buy tickets, grab a snack, and wait where they could see the buses coming and going. This facility was built for machines, not people; it would need an injection of humanity.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

A shortlist of qualified architects was invited to submit their ideas. The problem had no easy solution. The site was neither interior nor exterior. Open to the air and the elements, the proposed solution had to provide a welcoming, comfortable, enclosed yet fully visible, environment within an aging structure that was neither warm nor inviting. The project could only occupy a small portion of the second floor of the parking deck, at a location dominated by escalators and limited by the movement of trains passing below.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

This document explains the successful design by Studio Twenty Seven Architecture. Their solution responded to the constraints of the site and fulfilled the requirements of the project brief, addressing the needs of the passenger population. But it also took the project to a higher level. Studio Twenty Seven used the project to raise questions about the nature of travel in the 21st Century. In the process they also developed an innovative method to build a geometrically challenging structure on a limited budget. The result achieves Union Station’s desire for design excellence, and it adds a new, small, but important icon within its walls.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment


Concept I: Coffers and Columns
Method: Prefabrication

The coffer is an ubiquitous architectural element in Washington DC. Union Station’s iconic coffered ceilings are a classic example, a perfect application of this detail by the station’s architect Daniel Burnham. Our design approach abstracts the coffer to its essence and builds a new, whimsical space using the resulting extruded forms. These minimal coffers become columns, supporting and framing the proposed activities and programs of the redeveloped bus deck. The result is a new iconic element that playfully references the Beaux-Arts architecture of Union Station.


Studio Twenty Seven Architecture Union Station Bus Terminal Fragment


Concept II: Customized Universality
Method: Repurpose industrial modules

Using the modularity of the buses themselves as inspiration, the design team investigated ways to employ recycled shipping containers as program spaces. Each unit would be customized in a manner that made it unique while fulfilling its designated function. The models created for Union Station could then serve as templates to create others that could be deployed at intercity bus embarkments nationwide.


Studio Twenty Seven Architecture Union Station Bus Terminal Fragment


Concept III: Viewers and Views
Method: Site built light construction

This design approach proposes a new division of space that is both interior and exterior, using a grade change at the periphery of the plaza to open up new vistas. An observation deck winds around a new suspended volume that delineates the ticketing lobby, bathrooms, and offices. The deck gives views over the drama of the Amtrak platforms below, but also of the bus deck, creating a waiting area that is about more than just waiting for a bus, it is about the theatricality and excitement of travel.


“Cause in my head there’s a greyhound station
Where I send my thoughts to far off destinations
So they may have a chance of finding a place
where they’re far more suited than here”


Death Cab for Cutie, Body Meets Soul

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Who would have imagined ten years ago that inter-city bus travel would be as popular as it is today? Since its heyday in the immediate post-war years, traveling by bus had steadily gone out of fashion as air travel became more convenient and less costly. Long-distance bus travel became the mode of last resort, and once-grand art deco and mid-century-modern bus stations became synonymous with urban decay and empty downtowns. But since September 11, 2001, with the imposition of new security regimes at airports, and increasing fuel costs globally, bus travel has had resurgence. Small, agile bus companies plying routes between specific cities tapped into a new market: the young, carless urbanite too busy to arrive at the airport two hours ahead of a flight, and too frugal to pay two hundred dollars to fly from New York to Boston. Competition spawned innovation and soon numerous carriers were offering wifi, movies and bike transport, all for a fraction of the cost of flying. The long-established legacy carriers soon got on board with the new generation, and by the beginning of this decade bus travel was back.


Todd Ray, AIA, Principal
Studio Twenty Seven Architecture

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

For cities, this presented a problem. The business model of the new, smaller carriers worked in part because they lacked the overhead of dedicated bus stations. Passengers were picked up and dropped off right on the street at specific locations. As more carriers popped up and their popularity surged, the number of buses idling for passengers became a new cause of congestion. Many cities have been unable to solve this problem. New York, for example, already has two large, overflowing bus terminals and the smaller inter-city carriers continue to embark from curbside. Washington DC, however, has been saved by Union Station.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Beginning in the summer of 2012, Union Station became the new central location for intercity bus travel in the nation’s capital. The transit center is located in an existing parking garage, suspended above the rail yard, and removed from the facilities and amenities of the majestic Beaux Arts masterpiece next door. Studio Twenty Seven Architecture was asked to design a solution that would provide amenities to the bus traveler without requiring them to leave the bus deck.

The design process began with research. Why this sudden need to aggregate intercity bus service into one facility? Why has bus travel become increasingly popular? What is the nature of travel, and what makes bus travel different?

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

While there are obvious economic reasons why bus travel makes sense, its recent success is based on factors other than cost. The return to popularity of bus travel is, in many respects, part of a larger phenomenon that can be roughly categorized as a collective search for tangibility, authenticity, solidarity, and a sense of place. This phenomenon also includes recent cultural shifts such as the return to high density living, shared asset models (Bikeshare, Zipcar), local food movements, and collective boot camp workouts. This shift coexists with technology that seems to offer the inverse – isolation under headphones and behind hand-held screens that endlessly distract. Somehow, in this mediated yet questing space, bus travel fits in. Bus travel is acceptable again because it has been reframed. Bus travel now has a new set of semiotics, and a new cultural ethos has embraced it.

Travel is, by nature, placeless. And placelessness has a two-fold meaning as it relates to travel: the placelessness of motion and the placelessness of points of departure and arrival. The first relates to the mental state we enter when we travel. It is a state that seems almost genetically programmed, as if we are channeling our nomadic, hunting and gathering ancestors. We search for signs and codes in our environment that help us understand where we are, even as that environment sweeps past. The unique codes become landmarks in our minds, the common ones merge into the background. This activity is both exciting and meditative. But the faster the mode of travel the more difficult it becomes to place oneself. This placelessness exists on a continuum. Travelling by bus is somewhere in the middle of that continuum as we now know it. Bus travel is more tangible, and more properly scaled to our inherent understanding of the world, than faster modes.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

The second form of placelessness is a byproduct of modernity, as some cultural critics and geographers have claimed.  1 It is the placelessness of dross scape, the highway median and contemporary commercial environments. This placelessness exists because of the speed of development and the needs of market economies. The design prerogatives that brought us the shopping mall, the highway strip, fast-food and fast-fashion interiors, have also spawned placeless homogeneity in the places where travel happens. The experience of one airport merges with another. Our innate impulse to find codes and signs in our environment goes unused because all the codes and signs are the same as the last placeless place we were in. We end up stimulated yet bored, and the experience of travel is cheapened.


Studio Twenty Seven wished to respond to these two forms of placelessness in designing the bus deck pavilions. We wanted to appeal to the placeless mental state that is excited and challenged by travel, but subvert the placelessness of transition spaces common to airports, train stations, and parking garages. And we wanted to speak to the cultural shift that has made bus travel popular again.


1. Edward Relph, Place and Placelessness (1973); Yi-Fu Tuan (1974), Anne Buttimer (1976), and others.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

We started by searching for a metaphor that signals these intentions, and we settled on that of a Zen rock garden. The most obvious connection was to the pure physicality of the site: a grey parking deck striated by travel lanes and dividing strips, in which we wished to strategically place small, iconic pavilions.


Secondarily, the meditative nature of the Zen garden, its implied field of movement sweeping around static formations, plays on the idea of travelers moving through the space, and alluded to the simultaneously exciting and meditative nature of travel.


Finally, our rock garden would not be a precious space, viewed but not touched; rather it would be a gritty, bustling space. A space where the theatricality common to the street would be in constant play in the garden, as trains and buses provide a continuous stream of new travelers and new interactions.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

In this garden there are three pavilions. One of the pavilions serves as “rocks” in the field. This is formed from two natural, ovoid shapes, merged together to create a complex geometry. This pavilion contains the ticketing and shopping kiosks, two programs that would fit easily into a non-orthogonal form.


Another pavilion is the rock garden’s “pochi,” or meditation porch, over-looking the neighboring arrangement. This pavilion serves as a waiting space, with a wood and glass enclosure for hot and cold days and a bamboo-encircled open air deck for mild days.


The last pavilion contains restrooms. Due to trains running below, this pavilion had to be set off at a distance to accommodate its plumbing. Because of this, and the pavilion’s purely utilitarian function, we decided that it should simply say what it is. A recycled shipping container would serve as the armature for a discreet comfort station.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Once we were committed to this design, the biggest challenge was constructing the merged ovoid pavilion. There are many examples of successfully executed complex architectural geometries out there in the world today, but few of them were done quickly and on a small budget. The design team attempted multiple approaches to the problem, but the most cost effective was also the most traditional: enlisting a shipbuilder. The details of this part of the project are explained in an accompanying essay, but suffice to say the integrity of the overall approach hinged on the success of this particular component. Without it our Zen garden would revert back to a parking deck.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Lastly, we wanted an element that referenced both the Beaux-Art symbolism of the Daniel Burnham designed station next door, and contrasted with the semiotics of the logo-laden shopping and food courts it contained. We knew that the ovoid pavilion would have to be carved into to provide entry points and fenestration, so we took the opportunity to use those carving “planes” as a messaging surface. This surface would serve the same function as the classical frieze on Beaux-Arts buildings, where a story might be told in statuary, or the names of iconic personages might be inscribed. The design team settled on Death Cab for Cutie lyrics, translated into Morse code dots and dashes, and programmed into a 3D router. The resulting surface was painted a bright yellow and applied wherever the ovoid was carved out.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

The final composition transforms a placeless place into a place for placelessness, where waiting for a bus inspires excitement for travel, incites the pleasurable theatricality of the street, and provokes a deeper reading of the signs and codes of the traveler’s environment. We hope that our project will help continue the renaissance of long-distance bus travel and add to the tradition of inspired design that Burnham’s Union Station, and the sleek bus depots of the mid- 20th Century represent.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Jonathan Grinham, Project Designer
Studio Twenty Seven Architecture


Since their debut, digital design and fabrication tools have driven innovation in architecture. However, to date, digital fabrication technologies are used mostly for high-profile, large-budget projects. This leaves a nagging doubt as to whether these tools are capable of addressing small scale and limited budget construction projects. For small projects, the gap between possibility and reality looms large. Below we explore three design and construction processes considered by Studio Twenty Seven Architecture to create the complicated geometry of a 500 square foot retail and ticketing pavilion on Union Station’s inter-city bus deck in Washington, DC.

In the end, only one of these processes was used to complete the project. However, we feel it is important to share the research into each alternative approach. Alongside the limitless terrain of virtual, digital landscapes within which many of today’s architectural muses reside, there is a complementary need for real-world applicability of these designs. Standard contract models, the skills of locally available workforce, fabrication technology, and limited client budgets, all conspire to suppress ambitious digitally derived projects. 1  This project successfully mediates the ground between a digital exemplar and traditional analog craft, creating a model for future practice.

As explained in the previous essay, Studio Twenty Seven Architecture was commissioned to design a waiting area, ticketing station and bathrooms, on the first level of a four story parking garage behind Union Station. The garage was recently repurposed as the terminus for Washington’s intercity bus traffic, but it lacked amenities for the passenger population. The site presented logistical difficulties for construction within these conditions, and the project schedule was considered fast track. 2

The decidedly unspectacular and spatially interrupted site suggested that each program piece be small and iconic, dramatic and inviting. To the design team, the transitional landscape of the bus deck called for a figural form, a pavilion that was to be an iconographic object within a field, but also accessible, and tactile, inviting interaction and commerce. The design team employed a metaphor derived from a Zen rock garden that would be a spatial and temporal signifier. Three options for this trope were developed, each based on a slightly different design and fabrication model. The design team felt that the only way to bring this project in on time and on budget was to consider multiple ways to create the project. Below we present each option.


  1. The construction of the pavilion was through a standard AIA Owner – Architect, and AIA Owner – Contractor model. Representative cost comparison used here is for the pavilion shell fabrication only and for baseline comparison purposes the cost do not account for work associated with mechanical, electrical and plumbing trades. All cost models are stated as a percentage of the final cost of construction.
  2. The US Secretary of Transportation mandated fast-tracking for projects with 24-7-365 public-use site operation, on government-owned property.

Model A

In the first design, we sought to create two independent, yet visually interrelated forms derived from a Mobius-strip. The design team developed the geometry from a woven figure-eight form, and then modified the surface articulation by placing sectional variants at three distinct locations based on how the space was to be used. Once the continuous Mobius surface was established, the pavilions were split into two distinct ovoid geometries, resulting in an open surface condition resembling mirrored letter “C”s in plan. This resulted in two, independent, amebic-like structures that share similar form and surface articulation .

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

In this approach building program is shown through sectional manipulation, resulting in compound-curved surface geometries. In order to create buildable surfaces out of fluid forms, we developed a strategy for creating planar quadrilateral panels. We wished to work with a minimum of edges and nodes, which create visual noise; and use flat, planar materials that would be more efficient to construct. We proposed using a multilayer building skin system composed of an exterior rain screen and thermal and moisture controlled load bearing plywood wall system. (Model A, fig 2, 3) Each subassembly was precisely modeled, including material dimensioning, fastener locations, alphanumerical codification of parts, and automation of a CNC cut file.

We expected that each approach to the project would require active collaboration between the owner, design team, contractor, and fabrication subcontracting teams; but the precision required for Model A assumed that the specialized trades would use expensive CNC cutting tools. The contractor sought out local millwork trades that could work with the 3-axis CNC cutting equipment and provide the high level of craft required for the parallel mesh construction. Mistakenly, the contractor assumed sole source responsibility would be cheaper. But having the same millwork specialist fabricate components and do the labor-intensive field assembly proved to be costly. The millwork specialist carried a cost premium – justifiable for precision fabrication, but not for time-consuming assembly. Furthermore, while the millwork specialist had the capacity to program and cut each material type, the complexity of the parallel PQ-mesh system exceeded their 3D modeling aptitude, eliminating the in house production of shop drawings upon which the accuracy of the cut files ultimately rely. Overall, Model A was 225 percent higher than the allowable budget.

Model B

In researching the feasibility of Model A we imagined the project would be built under a standard contracting model. This was, in fact, one of the reasons Model A failed on cost. With Model B we shifted from a typical AEC contractual model to a ‘design assist’ method. In design assist, the architect supplies the subcontractor with fully developed design drawings and 3D modeling geometry, but not construction documents. The design assist subcontractor then designs, engineers and constructs all details required for fabrication. The architect provides design intent review and oversight through the shop drawing process.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

The design team collaborated with two fabrication specialists. Each specialist provided a different construction methodology derived from the original fluid form. The first method, fiberglass reinforced panel (FRP) system by a digital fabrication specialist, was derived from open-molded panels formed through 5-Axis cutting methods and suspend on a site-constructed skeleton of heavy gauge framing. The second method, a free-formed steel monocoque construction by an international shipbuilding specialist, was based on 3-Dimensional CNC cold forming of pre-shaped steel sheet. The compound-formed panels were to be reinforced through steel ribs, and assembled on site, (fig 05). Both methods relied on a repetitive, piece-part system to reduce overall cost. With this in mind, the design team re-configured the two pavilions using a single, ovoid geometry inverted about the XZ plane and rotate to produce the impression of two unique geometries. By strategically locating window and door openings, we further reduced the cost by minimizing the number of unique cuts and overall panel count.

Model B provided a more fluid construction delivery model, ensuring quick completion, and reduced liability to the AEC team. However, the reduced liability resulted in higher embedded costs. The Architect-Owner Contract did not allow additional design fees for a design assist contract. Instead, design fees were embedded in construction cost. The use of both molded FRP panels and cold-formed steel proved to be cost prohibitive. Although attempts were made to reduce the total number of molds, the initial tooling for the FRP panel molds carried a 5 to 1 cost relative to material and labor, resulting in a 400 percent construction cost. Additionally, the cold-formed steel structure, while a novel contemporary fabrication technique that provided increased material efficiency through a true monocoque structure, carried inescapably high material cost and design fees for proprietary engineering and programming, resulting in a 300 percent construction cost.

Model C


The final design presents a paradigm shift, by moving out of the digital realm mid-way through the process, and employing traditional craft for fulfillment.  Although digital tools are required for realization of the design, the final construction represents a successful engagement of designer-driven geometric form making and subcontractor trade expertise.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

For Model C, the design team took the twin pavilions of Model B and joined them into a single booleaned ellipsoid. The client had already embraced the ovoid geometry, and was excited by the idea of melding the two forms together. The ellipsoid that resulted could be panelized into strips, or peels. Responding to contractor feedback, we re-designed the pavilion based on a strip-built morphology. This translated into a buildable system by using fiberglass reinforced panels bonded to a fiberglass rib structure. This approach was the most viable on all levels: in the cost model analysis, in spatial and material uniqueness, and simplicity of fabrication and delivery.

This approach essentially “collapses the skin”; in lieu of the costly multi-layered wall assemblies used in modern envelope systems, a single source structural monocoque system was used. The design team worked directly with a marine industry specialist. To meet the budget, the consultant suggested using flat open-molded panels, and pointed out ways to trim costs by reducing the surface-volume to plan-area-ratio. This reduced the time required for field installation, and kept the whole package under the 16-foot maximum highway shipping width. Driven by these fabrication simplifications, Model C became a further evolution of the design both formally and programattically.

The geometry provided quarter-spherical symmetry, which allowed for a controlled number of repeatable flat-formed panels depending on the desired smoothness of the form. To meet the budget, we decided on an ellipsoid based on nine panel templates. Each of the fifty-two panels require for construction could be formed from these nine templates. (see fig 11). Intersecting the ellipsoids allowed the two independent shells to be prefabricated offsite, shipped, then bonded on site.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Figures 8, 9 and 10

Yet, despite our new approach, the skin was still too expensive. To trim the expense we literally trimmed the form, using a stereotomic language of cutting planes to create “pulp” surfaces where the volume was sliced away like a fruit.  These became legible as entries and pedestrian throughways by expression of color and texture at the sliced conditions – the form’s proverbial ‘pulp’.  The resulting ‘pulp’ condition at the slices created an opportunity to introduce a new surface texture.  The team explored multiple  surface pattern options, generated by contour lines made by a 2-inch diameter ball end mill on a 3-axis CNC router.  This technique reduced production time but retained the ability to cut paths with a large width and minimal depth. The final pattern, a ‘dash’ and ‘dot’ pattern, was derived from a Morse Code translation algorithm. It provided a visually compelling texture generated from contextual lyricism, made with cost effective tooling. (fig 09.)


The shift from digital to trade craft required a shift away from conventional contract-specified processes as well.  While the ellipsoid geometry provided a universal form that could be easily modeled through descriptive geometry and without the exchange of digital files, the subcontractor lacked the in-house modeling resources to reconstruct the intended design.  For this reason, and the abbreviated schedule, the design team provided background drawings for the marine specialist to develop layouts for FRP panels, “pulp” walls and entries, and structural ribs.  CAD files were provided to plot these templates at full size.  The curved shape of each developable fiberglass panel was hand cut using printed paper templates. (fig 12.) These were labeled alphanumerically corresponding to  assembly diagrams (fig 08). This allowed for all molds to be constructed on flat surfaces and the curved frames to be shaped around rib and batten formwork standard to the boat building industry.


Given the abbreviated schedule and the associated cure time of the composite materials, production and assembly required simultaneous processes. Fiberglass molding had to be calculated to match staging of the assembly.  First, the flat, FRP composite ‘Pulp’ end wall shapes were assembled on a steel framed bed – the individual shells would remain attached to the bed for secure shipping and delivery. Second, ‘L’ shaped ribs, molded from architect provided templates were then bounded to each end wall. This assembly of the end wall and rib sections provided a skeleton on which each of the preformed developable FRP panels could then be fully bent into place and bonded to the ribs.  Third, the panels were then trimmed to ensure a contiguous edge condition at each of the end wall conditions. Finally, the two separate shells were shipped to site and bonded along their intersection.


Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Figure 11


Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Figures 12, 13

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Figures 14, 15

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment



Design and construction of the final fiberglass reinforced monocoque structure proved to be a cost effective method that maintained design intent and introduced opportunity for novel open-molded techniques.  Furthermore, lessons learned from both Model A and Models B recognized the fundamental need for a monocoque structure, a proverbial ‘collapsing of skin.’  In contemporary practice and academic research, monocoque structures are idealized as a symbiosis of form and function.  The use of a structurally loaded skin, or a semi-monocoque skin reduces total component quantity, skin assembly complexity, reduces subcontracted trades, and isolates contractual liabilities.


Through intensive research, a complex digital design was realized using hand-crafted fabrication technologies. For small projects, the gap between possibility and reality may be overcome by looking beyond the digital. The Union Station bus deck pavilions  successfully traversed the ground between digital conception and analog realization, creating a model for future practice.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Ed Rahme, AIA, Principal, THINK architecture
Design Project Manager, USRC

Washington DC’s Union Station was built at a historical inflection point. At the turn of the 20th Century the nation was industrializing, and modes of transport were being revolutionized. Today, in the first decade of the 21st century, Union Station stands as an icon of that earlier moment; even as our transportation infrastructure continues to evolve. But beneath its Beaux Arts façade, Union Station is going through a rebirth as a modern, world-class, intermodal transportation hub.

In 1907, the term “mass-production” became part of the collective lexicon. Mechanization was considered the ultimate sign of human progress. It influenced the design and production of all aspects of the built environment, from locomotives to tableware. Machines produced objects faster, more easily and for less money.  Within the culture of art and design, these new technologies posed difficult questions. While some viewed mechanization as a tool to advance the design arts, others saw it as a threat to their character and craft.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Frank Lloyd Wright saw how design in the machine age could capture a new spirit even as it lost the character of the hand. In his 1901 article titled The Art and Craft of the Machine, Wright observed “the machine has dealt Art in the grand old sense a death-blow, no one will deny.” However Wright recognized that machines are tools of the human mind, and could launch a whole new era of design possibilities:

“The machine, by its wonderful cutting, shaping, smoothing and repetitive capacity, has made it possible to use it without waste that the poor as well as the rich may enjoy beautiful surface treatments of clean strong forms…”

Written over a century ago, Wright’s vision for new methods of production could easily apply to a description of today’s computer-driven design and production methods. As Union Station moves into a new century, it is appropriate that future transformations be driven by design and building techniques of our new era.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment
Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Studio Twenty Seven’s design for the Union Station bus pavilions is aesthetically bold and bravely innovative. Our process is emblematic of the current moment. The studio employed the latest digital design tools to create timeless spatial solutions, but used hand-crafted production techniques to build the project. Our process included a detailed examination of the use and function of the space, analysis of pedestrian traffic patterns, lines of sight, vistas and focal points to determine where and how the pavilions might serve to orient people in a complex series of spaces. While our assessment of the space and program is rooted in historical methods of analysis, our design for the built elements advances the discipline of architectural design through the use of leading research and numerically controlled modeling software. Pre-fabrication included 3-D modeling, but in the end the production process relied on practitioners of an analog craft to achieve digital results.

The bus station pavilions herald a new time and new approach to fabrication and construction of buildings particularly appropriate for Union Station. From the majestic solidity of the original Union Station facade, to the buoyant ephemerality of the new pavilions, the juxtaposition of the new within the old continues the storyline of imagination, evolution and advancement.

Studio Twenty Seven Architecture Union Station Bus Terminal Fragment

Union Station List of Images:

Cover image: Transit pavilion detail; image credit: Studio Twenty Seven Architecture

2-3: Union Station main waiting room, 1915; image credit: Library of Congress
4: top: Union Station entry facade, image credit: Union Station Redevelopment Corporation
4: bottom: Union Station rear facade, image credit: Tim Haas Associates
6: Chinatown inter-city bus route map; Graphic from ‘Everything but the Chickens: Cultural Authenticity Onboard the Chinatown Bus’ report by Urban Geography.
7: Satellite image Washington DC; image credit: Google Earth
8-9: Union Station bus deck; image credit: Studio Twenty Seven Architecture
10: Bus deck concept renders; image credit: Studio Twenty Seven Architecture
12: Pavilion 3, interior; image credit: Anice Hoachlander
14: Satellite image Washington DC; image credit: Google Earth; graphic: Studio Twenty Seven Architecture
15: Union Station bus deck; image credit: Studio Twenty Seven Architecture
16: Union Station bus deck; image credit: Studio Twenty Seven Architecture
18-19: Pavilion’s 1,23, exterior; image credit: Anice Hoachlander
20: Waiting deck; image credit: Anice Hoachlander
22-23: Amtrak waiting room, Union Station; image credit: Amtrak
24: Bus deck insertions; image credit: Studio Twenty Seven Architecture
25: top: image credit: Sophia Zelov
25: bottom: Zen Garden; image credit: Thomas Faivre-Duboz
26-27: Union Station bus deck; image credit: Studio Twenty Seven Architecture
28-29: Pavilion axonometrics; image credit: Studio Twenty Seven Architecture
30-31: Pavilion 1,2,3 with waiting deck; image credit: Anice Hoachlander
32-33: Pavilion 1,2,3,4 with waiting garden; all images credit: Anice Hoachlander
36: Pulp studies: image credit: Studio Twenty Seven Architecture
34-35: Pavilion 1,2 under construction ; image credit: Studio Twenty Seven Architecture
38: Waiting garden; image credit: Anice Hoachlander
39: top: Waiting garden; image credit: Anice Hoachlander
37: bottom: Plaza with Pavilions 1,2,3; image credit: Anice Hoachlander
42: Model A; image credit: Studio Twenty Seven Architecture
44: Model B; image credit: Studio Twenty Seven Architecture
46: Model C; image credit: Studio Twenty Seven Architecture
48: figure 8: Unfolded geometry; image credit: Studio Twenty Seven Architecture
49: figure 9: Pulp model studies; image credit: Studio Twenty Seven Architecture
49: figure 10: Final pulp model; image credit: Studio Twenty Seven Architecture
51: figure 11: Panel geometry; image credit: Studio Twenty Seven Architecture
52: figure 12: Workshop cutout; image credit: Compmillenium
53: figure 14: Workshop assembly; image credit: Compmillenium
53: figure 15: Site assembly; image credit: Compmillenium
54: top: Pavilions 1 and 2 delivered by flatbed; image credit: Chris French, Monarc
54: bottom: Pavilions 1 and 2 in place; image credit: Studio Twenty Seven Architecture
56: top: Union Station under construction; image credit: Library of Congress
56: bottom: Pavilion 3 under construction; image credit: Studio Twenty Seven Architecture
58: top: Pavilion construction workshop; image credit: Chris French, Monarch
58: bottom: Pavilion delivery; image credit: Studio Twenty Seven Architecture
59: On site assembly; image credit: Studio Twenty Seven Architecture
61: Sight line study; image credit: Studio Twenty Seven Architecture
62-63: Pavilion 1,2, waiting garden; image credit: Studio Twenty Seven Architecture


Union Station Redevelopment Corporation
Nzinga Baker, Vice President
Ed Rahme, AIA, LEED-AP, Principal, THINK Architecture, USRC Design Project Manager Union Station Parking Garage, LLC
Stephano Dubuc, EPARK, President and Director of Operations
Jack Hall, Project Manager

Pavilion Structural Engineer:
Ehlert/Bryan, Inc.
Stephen Ahart, P.E, Senior Project Engineer
James Leeuwrik, P.E., Project Engineer

Garage Structural Engineer:
Tim Haas
Kevin Carrigan, P.E., CAPP, Director of Engineering

Monarc Construction, Inc.
John Bellingham, President
Chris French, LEED BD+C, Preconstruction Coordinator
Wayne Kirk, Senior Project Manager
Mark Celia, Assistant Project Manager
John Whitson, Superintendent

Information Pavilion




Union Station Project Designers:
John K. Burke, AIA
Todd Ray, AIA
Sophia Zelov
Jon Grinham

Katty Amrimoeini
Craig Cook
Ray Curtis
Andrew Davis
Ben Hoelscher
Hans Kuhn
Claire Lester
Jacob Marzolf
Natalie Mutchler
Jason Shih
Jim Spearman

Thanks to: Beverley Swaim-Staley, Nzinga Baker, everyone at the Union Station Redevelopment Corporation, and Ed Rahme at THINK architecture.


Studio Twenty Seven Architecture is a collaborative design and research practice based in Washington DC. For more information and to stay up to date with Studio Twenty Seven, please visit our website at

Point of Contact:
John Burke, AIA


1600 K Street NW, Suite 800, Washington, DC 20006
All material is compiled from sources believed to be reliable, but published without responsibility for errors or omissions. We have attempted to contact all available copyright holders, but this has not been possible in all circumstances. We apologize for any omissions and, if noted, will amend in future additions.

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