by John Sullivan III
The design process began by testing the programmed area on a site model which included all of Libe Slope, the gorge, and the Arts Quad, using clusters of volumes representing the main components of the Museum. It was estimated which of the support areas might be placed below grade for convenience, and for the reduction of the building volume. Starting from a scheme with a low, broad massing, the idea evolved quickly into a slim tower: open to the south, perforated east and west, solid to the north. We discovered immediately that engaging the site with a terraced low block was not successful; the actual buildable site area was not large, and terracing required a breadth of surrounding green space to give a sense of the building emerging from the land. Whatever strength and interest it provided was negated by its density at grade, choking the view from the Arts Quad. This exercise revealed that by simply raising and dispersing some of the volumes seen from the Arts Quad, while maintaining the simple, rectangular silhouette seen from the bottom of Libe Slope, transparency could be achieved without losing the bold statement. The fragility of the site, in tandem with the quantity of functional space to be above ground, warranted the tower concept. The development of the scheme was to be a continuation of this testing process, and one of simplification—a joint strategy incumbent upon a building type that allows (and requires) so much design freedom in its creation.
The abstract block being studied on a small scale in the contextual model was a diagram of the program’s components. Functions were grouped into above-grade and below-grade categories; those above grade were further split into gallery (low zone) and “other” (high zone). The areas were compared and the uses assessed for stackability (convenience and appropriateness). This analysis of the program produced a stacking diagram to complement the one in the program illustrating plan relationships.
A scenario was formulated to test the disposition of the program spaces and to define a rough framework for the vertical massing model. From an entry court, one would ascend in gradual levels through the permanent collection galleries, and descend in similar steps through the temporary exhibition galleries. The upward sequence would conclude with the exterior sculpture terrace, and the downward circuit with the experimental gallery and lecture room. The large gallery for temporary exhibits was placed a half-level below the lobby, and the main galleries for the permanent collection were to be a half-level above it. Each of the independent galleries surrounding the lobby court was connected to the next by a narrow bridge with the spaces between capped by a floating glass roof, allowing the transparency to be lateral and vertical. The large storage spaces were located in the lowest basement with various types of work areas, mechanical rooms, and a loading dock accessed by tunnel. The program had considered the administrative areas abstractly as a single grouping, producing a large “footprint”—this was to be the perfect volume to form the upper outline of the overall rectangular shape and to act as canopy for the Sculpture Court.
The program provided for semi-public spaces—the study galleries—which would be classrooms, with exhibits designed by professors to accompany their courses. In conjunction with the print room which would have similar student use, these spaces formed the stack of floors which created the tower and visually shaped the five-story high lobby space.
The restriction of natural light in the galleries validated continuing our development of a spatial concept to address “museum fatigue,” which had begun with our addition to the Des Moines Art Center, and had been expanded upon at the Everson Museum in Syracuse: modulating the museum exhibit circuit by creating individual and varied gallery volumes separated by open links. A string of windowless boxes, while archivally conscientious, is one of the contributors to fatigue; orientation is another. These proposed interruptions might be to daylight, to a central court for orientation, to distant landscape, or to all three. This separation gives the visitor a pause, and benefiting from a change of light and view, allows reflection upon what has been seen before proceeding to new riches. For a small museum with diverse collections this device also facilitates a transition between periods and scale of display.
The consequence to the exterior is its potential to articulate parts of the building, giving scale and animating a silent block to welcome the visitor. The facades of classical museum buildings resolved this design issue with stone pilasters or colonnades, empty or statuary-filled niches, and blind windows. This philosophy of movement was to fully evolve in the subsequent design of the East Wing of the National Gallery in Washington, D.C. Architectural critic Wolf von Eckhardt was quoted in an article on the Johnson Museum in Museum News (September 1974) as saying it is “a perfect museum. You don’t suffer museum fatigue, because the gallery spaces vary in size and height. There is always a point of rest—a place to look out the window or some other little ‘intermission’.”
The critical issue was the creation of an engaging, exciting spatial structuring of the vertical gallery sequence. Programmatic requirements assisted the conceptual resolution: at polar ends were the lecture room (total enclosure) and the secure sculpture court (exterior space), each requiring the same public access as the galleries. By linking them to the vari-sized galleries, and spiraling this loose chain of spaces vertically as a three-dimensional jigsaw puzzle of volumetric shapes in a pinwheel around four sides of the central open-space, it would be conceivable to move in gradual increments of quarter- and half-levels through the sequence of exhibition spaces with the desired intricate spatial interpenetration. Placing the lobby platform at the point separating the permanent collection galleries from the experimental and temporary galleries completed the idea. The scheme was to be validated by the forthright circulation system, with a maximum distance of two floors for the visitors to travel up or down from the lobby. The fourth side of the pinwheel became the base of the tower, anchored to the core and counter-weight to the cantilevered galleries. A simple block, its stacked layers of working spaces are the background to the animated elements playing in the sun. From the north its upright form is an extension of the sheer wall of the gorge beyond; from the south it arrests the sweep of Libe Slope. As the tower rises, its engaged core is defined by a long, vertical, recessed glass slot providing glimpses east and west from the upper levels.
The lobby, like an overture, establishes the themes and mood of the building. In this instance the prelude identifies the ambiguity of enclosure: it is both an interior and an exterior space. And it defines the building concept: an articulated assembly of enclosures joined by glass, where the focus alternates between the functional spaces and glimpses of the landscape.
It had been established at the outset that the meeting room, along with the lobby, should be a highly glazed space to frame the panoramic view. By capping the tower with a penthouse in the form of a glass-enclosed loggia, it was possible to have Ezra Cornell’s view without any intervening vertical structure; simply tall, broad sheets of glass, stretching wall-to-wall, joined by thin lines of translucent silicone sealant—an outdoor space engaging nature, like the lobby.
In the designing of a complex building form it is crucial to create a framework, or modular grid, for an organized development of the plans. This unit of measure, and armature for planning, is vital for establishing order during the progress of the design. It is also useful for the coordination of plan with elevations, inherently providing a rhythm to the structure. It is an indispensable method for facilitating communication with the builder at the end of the design process, and provides a base for systemization which can significantly reduce cost. All the buildings designed by Pei Cobb Freed & Partners have been structured by a module, shaped and sized to the particular needs of the building design. For the East Wing of the National Gallery, the module was a triangle. For the Johnson Museum it is a 4’-6” square. For example, the vertical slot window in the tower is 4’-6” wide, the piers supporting the cantilevered fifth floor are 13’-6” wide, and the great opening defining the lobby is 45’ wide.