"The Patent Office Building, an American cultural treasure and National Historic Landmark..."

The design solution for the enclosure of the Patent Office Building Courtyard offers a remarkable oppurtunity for the Smithsonian Institution, and its chosen architects, to re-confirm the building's unique institutional and architectural pedigree - "America's temple to the industrial arts" - by adding a dramatic contemporary chapter to the building's history.

Fortuitously, the building's original purpose - the display of inventor's models submitted with patent applications - embodies a spirit of technical and artistic progress that the existing building will share with the newly enclosed courtyard.

"The courtyard addition should support a state-of-the-art museum facility, set a standard for architecture, and signal a commitment to design and innovation," according to the building program. Eric Owen Moss Architects intends to follow in the American tradition of invention established by Alexander Graham Bell, Thomas Edison, and architects Robert Mills, Thomas Walter and others, that will "distinguish the museum for the next millenium."

FIELD OF RODS

The roof design that encloses the Patent Office Building courtyard is poetically and technically unprecedented: a dense vertical amalgamation of glass and steel rods of varying lengths offers an ever-changing presence of light and sky viewed through a spectacular, seurat-like field of shinning points. Simultaneously the composite structure reaffirms the prominence of the original courtyard experience -- the granite and sandstone walls that form the "great room", now sharpened and re-focused in a new, reflected light.

The iconic roof is not simply dramatic. In pragmatic terms, the field of rods is both a courtyard enclosing volume, and a versatile, multi-purpose composite that simultaneously provides structural, technical, and staging services for the great room.

STRUCTURE

The field of rods are lifted on 8 steel columns positioned on the original building foundation line that parallels the courtyard walls. 4 steel vierendeel truss frames span the columns and are integrated into the field of glass rods. These frames form the principle vertical load carrying elements.

Perpendicular to this primary structure is a series of deep cable trusses, the principle feature being the large glass tubes that both create the main visual shape of the roof but also form the compression struts for the trusses. The lower chord of these secondary trusses is a draped cable that follows the shape of the lower surface. In order to resist the small uplift wind loads, these cables need to be lightly stressed and attached back to the existing structure at the east and west walls of the courtyard. The upper chord of the truss is formed by the roof rafters, allowing an efficient visual and structural integration of elements.

The use of glass as a strut is a novel application but one which uses glass in it most efficient manner – in compression. The tubular shape, apart from its aesthetic, is also a very efficient strut shape. The large number of fins, the use of laminated glass and the requirement for the tubes to be split all contribute to a multi-redundant structure that will remain in place and have a significant load carrying capacity even in the unlikely event of a breakage.

The composite roof serves the great room as a horizontal proscenium, spanning the courtyard with catwalks for workers to install acoustic and exhibit hangings, providing a variety work stations for lighting, projection, and multi-media equipment, and most uniquely, bridging the floor below as a sequence of structural glass trusses spanning east-west between the 4 column supported steel trusses.

ACOUSTICS

The proposed design of the glass ceiling and tube array provides an integrated solution to all the acoustic requirements of the courtyard. As a multi-function space, the courtyard is required to work for many different types of performances requiring different acoustic conditions, and the ability to house both amplified and un-amplified events. This requires a flexible solution to the acoustics that allows variation of the conditions to provide an appropriate environment for each use.

The large volume of the room and sound reflective wall and floor requires a strong gesture to provide a solution to acoustical response. To do nothing in a space of this scale would result in both excessive noise and reverberation, especially with a reflective glass ceiling. With both high reverberance and long path specular reflections from the planar wall surfaces and, amplified sound would quickly become a cacophony of noise, there would be terrible problems with feedback between microphones and loudspeakers, crowd-noise would become overwhelming and the delicate sound from smaller scale events within the space would be lost. The proposed design of the tube array offers a mechanism to solve these problems and to modulate the acoustic response of the space to suit the various functions.

The profile of the tubes is developed to form a curve that will diffuse the sound and disperse reflections that would otherwise reflect continuously between the flat ceiling and floor. Sound can either travel between the tubes and be diffused within the vertical tube array, or alternatively it can be reflected or diffused from a ‘plug’ on the end of the tube. This plug offers a surface to provide a strong reflections to both musicians and audience performing within defined zone of the courtyard. The contoured form of the underside of the tube array has been derived to provide the lowest point at the potential stage locations at the end and side to give the best acoustical reflection sequence to the stage and audience.

The tubes also provide an opportunity to integrate both sound absorbing and sound enhancing mechanisms within the elements, integrating them into a single system that both simplifies and liberates the architectural design of the external glass façade and structure. The natural variation in length of the tubes offers the potential to use varying resonant frequency of the tubes to provide damping to the reverberation across the whole frequency range. This mechanism is similar to the use of resonators in theatre from Ancient Greek times to the present day to tune the acoustics response. Using a combination of active and passive elements with the tube, the tubes will be able to both absorb sound and to radiate sound in a controlled manner. This effect could be used to great affect for performances with the Courtyard.

LIGHT

827 rods, each .80 meters in diameter and varying in length from 3.5m to 9m, support horizontal glass sheets that enclose the court and protect the new interior from the weather. The rods continuously reflect and refract natural light into the event space below. The cylindrical shape and hollow configuration of the glass rods enables myriad lighting opportunities. In an experiential sense, from hour to hour throughout the day and night, and from day to day throughout the year, the courtyard space will be perpetually remodeled with reflected light.











There is also the option to project light up from the rod tops, using the sky as a black canvas, to produce a glowing field in the night sky that announces the renewal of both the Patent Office Building and the central business district of Washington D.C.








Program: "Democracy's Room" multi_purpose hall

Area: 3,068 Sq.M

Selected Awards:

Second Place, Washington D.C. 2004

Selected Publications:

Arch’it (online architecture magazine),
by Paola Gioioconia. Eric Owen Moss
Architects: Smithsonian Instituion, Patent
Office Building Courtyard Enclosure
Competition May 2004.


































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