Mies van der Rohe in Chicago

Seagram Building, New York, 1958 Note that in the section of the building on the left the mullions are filled with stone instead of glass. This is the elevator service core of the building.

MIES VAN DER ROHE IN CHICAGO EDWARD R. FORD Written for but not included in the second volume of The Details of Modern Architecture.

MIES VAN DER ROHE IN CHICAGO EDWARD R. FORD

"I would prefer to march without a flag."

Ludwig Mies van der Rohe, 1927 It was more fate than design that brought Mies van der Rohe to Chicago in 1938. He had been reluctant to leave Germany. He had hoped to go to Harvard rather than the Illinois Institute of Technology (IIT), so he perhaps did not conscientiously seek out a place so close to the heart of American industry. The work he did there seems that of another man than the European Mies. The rich palate of materials slowly became monochromatic. The dynamic elemental compositions evolved into symmetry. The complex assemblies of planes rather quickly became simple prisms. Whether the new surroundings, or at least the new conditions-American building techniques and the design of semi-industrial laboratories-were the primary reason for this is not clear, but it provided the stage.

Although American industry played its part in the creation of this style it had little to do the idea of manufacturing buildings like planes or automobiles, a concept to which Mies was somewhat cool. Like many of his modernist European contemporaries, he was inspired by Henry Ford, but he had his reservations. He wrote in 1924: Nothing illuminates more clearly the situation in which we find ourselves that the fact that Ford's book could trigger such a strong reaction here in Germany. What Ford wants is simple and illuminating. His factories show mechanization in dizzying perfection. We agree with the direction Ford has taken, but we reject the plane on which he moves.

Mechanization can never be goal, it must remain means. Means toward a spiritual purpose.1 He was equally cool to the concept of rigid standardization. He wrote in 1927: The battle cry "rationalization and typification," along with the call for the economizing of the housing industry, represent only parts of the problem, for, although important, they have significance only if seen in right proportions. Next to them, or rather above them, stands the spatial problem that can only be solved by creativity rather by calculation or organization.2 In his notebook he wrote, also in 1927: "Do not standardize everything. Only when it makes sense. Why tie one’s hand voluntarily?" and "There are people who would like to make a Ford Factory of nature." Likewise, economy of material for its own sake was suspect, "How senseless economy becomes when it only wants economy." In subsequent years his comments on industrialization were more and more equivocal in comparison with those of Gropius and Le Corbusier.3

THE RESOR HOUSE What first brought Mies van der Rohe to America was not the directorship of IIT but a commission. Stanley Resor had hired Mies to design a house for his Wyoming Ranch, and in 1937, before having accepted the job in Chicago, Mies was in Jackson Hole, Wyoming, sketching the house. The site was spectacular, located on a small tributary of the Snake River with the Teton Range as a backdrop, but it was not without complications. The initial design of the house was done by Philip Goodwin, co-designer of the Museum of Modern Art, who conceived the idea of a house spanning the stream.

Construction had proceeded as far as parts of the ground floor and the piers to support the house over the stream when Goodwin resigned, and Mies was required to incorporate the existing fragments into the design.

Mies’s point of departure was, given the times, not surprising. Like many architects of the late 1930's he seemed as fascinated by vernacular as he was by the industrial, in fact he saw a certain equivalency between the two. In a 1923 lecture he presented images of an Indian tent, a leaf hut, various Eskimo dwellings, and German farm buildings. He said of the leaf hut, “Have you seen anything more perfect in terms of function and use of material?” Is that not the best possible use of the jungle shadow?” He ended his lecture with what he considered the contemporary equivalent, the liner Imperator. 4 This lecture was a early manifestation of what was to become a general movement of the 1930’s, what Siegfried Gideon called the New Regionalism. Aalto was looking to Karelia, Gropius and Breuer to New England, Le Corbusier to Catalonia, all to find architectural truths long suppressed, in theory, by the weight of architectural history.

This desire to be industrial and the simultaneous desire to be vernacular combined with the character of the site, the complications of the existing conditions, and Mies’s first confrontation with the American building industry to produce a result that externally bore little resemblance to what came before or after in his work.

The interior had more affinity with his earlier buildings. While the Resor house was developed using indigenous materials (or rather materials that appeared to be indigenous), it employed many of the details he had used in Europe. The Resor house in fact has much in common the Barcelona Pavilion. Both have no exposed structural elements; both use entirely layered rather than monolithic construction. Although they are both structurally expressive, they are expressive in entirely symbolic ways, and the perceived structure is a highly abstract and in some ways inaccurate portrayal of the real structure.

Similarities of detail, however, are obscured by dramatic changes in materials. The stucco of Barcelona becomes Cypress boarding at Resor. The polished, veneered stone slabs of Barcelona become the rough, solid fieldstone walls in Wyoming. The reasons for the change of material are not necessarily contextual-Cypress is hardly "contextual" to Wyoming in any case-but again a reflection of a pursuit of the qualities of the vernacular.

The structure of the Resor house began with a grid of steel columns located on the existing piers, each made from four steel angles, similar to the columns used at the pavilion in Barcelona and the Tugendhat house. Spanning between the columns were 12inch deep steel wide flanges supporting the floor and roof. Only the major beams that connect the columns are steel; the typical floor and roof joists are specially made 2 inch x 14 ½ inch wood sections. Like many American “steel” houses the Resor house is at least 50 percent wood.

This hardly matters, as little of the structure can be seen. The columns are the only apparent structure of the upper part of the building, as the complex steel and wood assemblies of the roof and floor are hidden behind the flat planes of cypress boarding. As in virtually all of his European work, and like most of his European contemporaries, Mies articulated the columns of the structure while suppressing the beams to maintain the principle, more accurately the illusion, of the free plan. The concept that the ideal modern construction system consisted of a thin flat concrete slab supported by columns is one of the main fictions of Modernism, one to which Mies subscribed. But even the steel angle columns are not really exposed structure as the steel is faced with sheet bronze U's and L's. The detail is similar to the Tugendhat house and Barcelona column covers, but the ends of the bronze facings are square rather than round. Bronze was selected rather than the chrome used in the European buildings to blend in with the cypress ceiling.

Despite appearances the roof is by no means flat. It is drained to the edges rather than to a central roof drain and as a result there is a box gutter at the top of the fascia board. This was a common detail in modern houses of the time, particularly those by Neutra, but it seems particularly inappropriate in a Miesian prism, even one as complex as the Resor house. The gutter is not totally out of keeping with the house, as the rectilinear volume of the house is slightly smaller at the bottom. Each layer of the wood cladding-fascia, siding, and baseboard-is slightly recessed behind the one above. This allows the projecting layer above to become a drip to throw the rainwater away from the joint below. Mies had used a similar detail in the Concrete Office Building project in 1923, where each concrete tray projects slightly for beyond the tray below.

The wood walls, which are in theory the "vernacular" parts of the building, bear little resemblance to any existing American systems. The walls are faced inside and out with 2 5/8 inch x 11-inch cypress boards joined with splines. Due to their depth, more than three times that of standard wood siding, they are largely self-supporting. All are held only by rails at the top, middle and bottom, joined with metal angles. The typical American solution to the wood wall, the one that was being used by Gropius in the same year for his own house in Lincoln, Massachusetts, consists of wood studs at 16 inch spacing covered with sheathing, ¾-inch wood siding and interior finish, a far more complex solution. What Mies’s system gained in simplicity it may have lost in economy. It uses greater quantities of finish wood, more sophisticated fastening methods (clips instead of nails) and has fewer safeguards against water penetration and infiltration, (no building paper under the siding). Mies’s desire was obviously to avoid building a secondary wood frame as is typical in steel assisted wood construction.

Franz Schulze points out that some of the rough sketches of the house show two solutions radically different from the final design.5 One employed a steel cable supported roof looking something like the Golden Gate Bridge. The other was closer to the final design but used diagonal cable bracing in the interior. In Mies’s subsequent work the tension cables never appear, and while many subsequent Mies buildings use diagonal bracing, it is for the most part concealed. The notable exceptions are the Convention Hall Project of 1953 and two projects designed with roofs hung from diagonally braced trusses, the Cantor Drive-In Restaurant and National Theater in Manheim. This aversion to cables and diagonals is best explained by Mies’s “classical” conception of structure, that architecture was at its best simply a question of solid, simple post and beam construction and not an affair of lateral loads and dynamic equilibrium. Arthur Schopenhauer had written that “architecture’s sole subject is support and load,” and Mies would have agreed.6 The Resor house opened the second phase of Mies's career, different in every way from the first. The Resor house was the end of Mies’s brief foray into the vernacular, but the beginning of more permanent changes of direction. Many of the differences between the American and European Mies were purely aesthetic. His American buildings were more regular, were more likely to be symmetrical and dealt more with precise volumes and less with planes. But the state of the American construction industry, as well as the opportunity to execute larger buildings, brought both a new set of possibilities and a new set of problems.

Above: Academic Buildings on the IIT Campus. Perlstein Hall is to the right, Wishnick Hall to the left.

Below: Wishnick Hall is to the right, Perlstein Hall to the left.

THE IIT BUILDINGS Between 1943 and 1958 Mies built twenty buildings for the Illinois Institute of Technology. Eight of them have exposed steel frames. Four of them have concealed and fireproofed steel frames. Seven of them, including the dormitories, have exposed concrete frames, and two of them, including the Chapel, are load-bearing brick. Many other buildings, some of the more important, were developed in great detail but not built, and the Miesian parts of the campus today are only a fragment of his original plan.

In contrast to the domestic and exhibition programs of his European work, IIT presented an opportunity for a vastly different type of steel frame building, but with complications.

On the one hand, the types and sizes of steel available and the methodology available for their connection made the exposed steel frame a real possibility for certain buildings. At the same time the larger scale of the buildings meant more stringent fire regulations, which inhibited, and often prevented, his ability to expose and express the steel frame.

Larger buildings also meant the need to accommodate larger and more complex utilities, particularly ductwork, and the need to incorporate these into the architecture of the building. This last consideration, something of an inconvenience in 1944, was a major problem by 1970.

Mies’s post-1945 work appears fairly unified in its attitudes toward structural expression but in fact he used three different structural types, each of which implies a different relationship between the structural frame of a building and the way in which it is portrayed on the building’s exterior: the exposed steel frame, the exposed steel frame clad with an analogous steel frame, and the ornamental frame in which the cladding is of different material than the structure that it clads. Mies seemed content to vary these typologies as conditions demanded and apparently was not concerned with any implied ideological inconsistency, and throughout the second phase of his career, would accept whichever of these three systems circumstances forced upon him.

Charles Jencks maintains that the buildings at IIT are devoid of any institutional or typological identity, are indistinguishable from each other, and are misleading as to their function in the visual clues that they give. But whatever the shortcomings of these buildings, and they have many, it cannot be said that they are devoid of any typological identity, although it is a typology too subtle for the taste of many. It is not as one might expect arrived at by an articulation of the difference in programmatic functions of the various buildings, but by a manipulation of the steel frame to achieve effects which were "monumental� for certain buildings, to use Mies's own term.7 Setting aside Crown Hall for the moment, there are three basic programmatic functional types of building at IIT each with its own constructional Methodology. The first group, the utilitarian buildings such as the Boiler Plant, are exposed one-story steel structures.

The second group, the academic buildings-classrooms, offices, etc.-are two to three stories and employ steel frames encased in concrete, non-structural steel and brick. The third type, the institutional buildings, were structures of major importance such as the Library and the original design for the Commons. They were also to be exposed steel

Left: Boiler House IIT, 1950. An exposed steel frame building with brick infill, built around an existing boiler.

Right: Corner Detail of Boiler Plant. Mies generally avoided exposed bolted connections, particularly on building exteriors.

structures but are one-story, sometimes containing mezzanines and sub-buildings within their long spans. In the original campus plan the Library and Commons are located in the center and ringed by the academic buildings, with the utilitarian buildings at the perimeter.

Uniting all these is a uniform grid, 24 x 24 feet, covering the entire campus. It is the largest of several modules, two others being 12 feet, a typical fixed window, and 8 inches, the nominal length of a typical brick. Mies used the 24-foot grid as a point of departure for all the campus buildings, locating the columns at its intersections but departing from the grid frequently to accommodate and to articulate functional differences-the need for a longer span for lecture rooms or a machine shops-but also in purely symbolic ways to articulate the importance of various buildings.

The rigidly uniform bay sizes of Le Corbusier’s houses of the 1920s were clearly, to their author, an expression of the standardization that a truly industrialized building culture would require. One might then suppose that Mies’s 24-foot x 24-foot grid was the result of a similar intent, that Mies saw it as an expression of industrial standardization, but this is by no means certain. The grid might just as easily have been an expression of the properties of material since its smaller subdivisions were based on the sizes of brick and glass. Mies, when asked the reason for grid replied, “Orderliness.” While the factory (particularly those in Germany by architects like Erich Mendelsohn) may have been the model for these buildings, industrialization, its products and its principles such as economy of material, were not.

The first steel building to be completed at IIT, the Minerals and Metals building, was of the utilitarian type. It used an exposed steel frame with brick infill and marked the birth of the first of Mies’s American building types in steel-the exposed frame. This system was applied to buildings as diverse as the Farnsworth House and the Berlin National Gallery. All these buildings had in common that the appropriate building code did not require fireproofing of the steel, usually because the buildings were only one or two stories. This was obviously the system of first choice.

The buildings designed soon afterwards also used exposed steel frames. They were to be two of the more important, the Library and Commons, and sadly, two of those not built.

They were evidently conceived simultaneously with the academic buildings built several years later, and Mies was deliberately developing two different characters for the two types of buildings. He said of these “institutional” buildings, "The Student Union and Library Buildings confronted us with different problems,…I wanted two buildings to have a more monumental character."8 Monumentality here meant a structure that was larger and thicker, and this was achieved by giving both buildings longer spans. While the academic buildings have the standard 24-foot x 24-foot structural bay with a few exceptions, the Commons Building and the Library were to have bays of 24 feet x 64 feet. As a result the beams are deeper, the columns larger, and of course are spaced farther apart, at least in the 64 foot dimension.

Both the Library and Commons have the standard 24-foot bay spacing along their long sides, and a 64 foot bay spacing along the short sides. In order to increase their “monumentality,� Mies exposed the deeper, thicker structure on the short side with the longer bays, but on the long sides with the shorter 24-foot bays he placed a glass curtain wall in front of the columns so the smaller bay is not apparent. Thus while in the facades of the academic buildings ornamental columns are added between very other real column in order to decrease the size of the typical brick panel, in the Library the columns are hidden behind the glazing and the wall is transformed into an almost unbroken 528-foot long expanse of glass. The relationship of the brick and glass infill changes as well. On the short sides, with the larger exposed structure and the 64 foot bay spacing, the infill is placed between the columns and girders so that the structure is visible from the interior and exterior. It seems odd, in retrospect, that these buildings were ever considered exercises in pure structural rationalism.

The utilitarian buildings presented special problems. Whenever possible, Mies used the 24-foot bay, but inevitably, because of the functions they contained, longer spans were sometimes necessary. The boiler house needed to accommodate a large existing boiler; the Minerals and Metals Building required a long, wide foundry, and the bays of these buildings were enlarged or even doubled. As in the Library he did not attempt to hide the longer spans, and thus the deeper beams where they occurred, but he did subdivide the resulting brick wall panels into 12-foot bays with additional steel sections, making them closer in character to the academic buildings.

There is nothing particularly functional about the structural distinctions. There is nothing wrong with a three-story classroom building with 24-foot square bays, although this is a bit small by contemporary standards, but the long 64 foot bays of the one story Library, using what must have been one of the deepest wide flanges available, then or now, is another question. Some spaces in the Library undoubtedly required long spans, but by no means all of them.

Mies also utilized the difference in brick wall panel size to exaggerate this difference between the institutional and academic types. Just as a floor slab carries a structural load, so must a wall panel carry the load imposed on it by the wind, and just as a floor slab must become thicker as it spans farther, so must a wall panel become thicker. The "span" in the case of a wall being the distance between the two floor slabs and between the columns, all of which act to support the wall panels in the way beams support a floor.

The Library wall panels being larger at the ends (24 feet x 64 feet, the same as the structural bay) span a much greater distance and are therefore thicker, 16 inches, as opposed to the 8-inch standard wall in the academic buildings. Since the steel columns are square, and the brick walls project substantially beyond the plane created by the steel frame.

A similar transformation occurs in the windows. A typical fixed pane of glass in Alumni Memorial Hall, one of the small-span academic buildings, is 6 feet x 6 feet and is thus Âź inch thick, and supported by mullions 1 inch wide and 3 inches deep. In the Library, which according to Franz Schulze would have used the largest pane of glass in America

Left: Alumni Memorial Hall, IIT, 1946. Unlike the academic buildings built subsequently, the window frames are steel giving a more uniform appearance, but probably a technically inferior wall.

Right: Corner of Alumni Memorial Hall. The facing frames stop at the column center line to reveal the corner of the column.

at the time, 12 feet x 18 feet, the area, and thus the load is much greater. The glass is thus ½ inch thick and supported by mullions that are 1 inch by 8 inches. As a result the library mullions project further and would have had a noticeably heavier profile.9 While the institutional buildings went unrealized, the academic buildings did not, and three were built in fairly rapid succession after 1945. The first of these, Alumni Memorial Hall, is in some ways the purest and according to George Danforth, became the model for its subsequent neighbors, Wishnick and Perlstein Halls. Although Alumni Memorial Hall seems at first glance only subtlety different from the executed Metals building and the unexecuted library, there is a major conceptual difference, for while the former had or were to have exposed steel frames, Alumni Hall did not, using a composite steel and concrete frame, only the latter parts of which are visible. Since, in contrast to the Metals building, the academic buildings are only two to three stories and have different uses, the building code required that the structural steel, i.e. the primary frame, be fireproofed while the secondary frame did not.

Whether or not this facing frame is ornamental depends on one’s definition of ornament.

It is “non-structural” as the word is defined by the building code, since it does not support the floor or roof. It does act to brace the brick wall and provide a point of attachment for the steel windows, but Mies built a number of buildings at IIT without facing frames and without apparent difficulty. It seems clear that however useful they might be, the real purpose of the frames is to visually represent the hidden structural steel frame.

The academic buildings have square bays, with concrete encased columns spaced at 24foot intervals along all sides. These are covered by the 8-inch thick ornamental steel frame, which is divided by additional steel members into 12-foot squares filled with glass or brick. This layer is interrupted at the corners to reveal the column, or at least steel angle covering the corner of the concrete, to form the famous Mies corner. This is the only location on the exterior where anything like the real columns are visible. The columns are of course visible from the interior, or at least their concrete casings are visible, but the viewer's perception of them is somewhat obscured since the interior space is broken up into small rooms and the floor structure is concealed by the suspended ceiling. One can only perceive with difficulty that this is an analogous covering on a real structural frame.

This is the second of Mies American constructional types, the analogous steel frame.

When building codes required fireproofing, and thus concealment of the steel frame, Mies constructed a second steel frame on the face of the wall in front of the real frame.

Although it often served to support the glass or brick of the curtain wall, it was in essence an analogous cladding, describing, not always accurately, the real frame below.

As in all of Mies's buildings, issues of craftsmanship, particularly joints and fasteners, are of major concern. The reveals between brick panels and steel columns have been discussed ad nauseam, but this type of expression is used only for joints between dissimilar materials, and between structural and non-structural elements, not between structure and structure or between steel and steel. These joints were not only

Alumni Memorial Hall Steel facing frame

Alumni Memorial Hall Frame Detail. Note reveals at brick/steel joint

Crown Hall, IIT, 1956 Oblique view

Crown Hall, Front View. Note the hierarchy of elements, the primary systemthe structural column and girder frames supporting the roof-the secondary system, the wide flange uprights supporting the glass, and the tertiary system-the small steel bars sub dividing and holding the glass.

unarticulated but rigidly suppressed. While all exterior structural joints of Alumni Memorial Hall are welded and ground smooth, all interior joints are bolted. In the finished building all the interior joints were covered, and concealed with a flat plaster ceiling. The purpose of the ceiling of course is not so much structural as to facilitate the placement of interior partitions, as most of the academic buildings are divided in to many small rooms.

Crown Hall, built in 1956, ten years later than the first series of academic buildings, clearly falls outside this typology. It contains no brick. It is on a 10-foot rather than the 12-24 foot module of the rest of the campus. Its steel frame is exposed outside the building. Its structural bays are greatly in excess of any of the other campus buildings designed by Mies. There are numerous theories for the many idiosyncrasies of this building, but technological change was clearly one of them. Crown Hall is the first of the IIT buildings to be air-conditioned. Hence the elimination of the large operable windows, the presence of large areas of fixed glass, and the deep suspended ceiling, totally concealing the roof structure from the inside, but creating a deep plenum for ductwork.

According to Myron Goldsmith the reason for the change from a 12-foot module to a 10foot module was quite simple, the fact that 12-foot glass lengths were unavailable. At this time the glass industry was switching from plate glass to float glass, since the latter process could produce smooth sheets without polishing. At the time of construction the maximum available width of float glass was 10 feet.

In any case the difference in module size is the least of Crown Hall's idiosyncrasies, for its 120-foot span is the longest of any Mies building at IIT, executed or unexecuted, other than the unbuilt Gymnasium, and is almost twice span of the 64-foot bays of the unbuilt Library and Commons. One might assume, as does Jencks, that this represents that the architectural school is in fact the most important building. More probably it is a manifestation of Mies's increasing interest in long-span building systems. This had already manifested itself in the Farnsworth house and 50 x 50 house and was to become a dominant feature of his later work.

The roof is supported by four rigid frames, spaced at 60 feet and spanning 120 feet, from which are suspended the wide flanges and metal deck of the roof proper. Only the four rigid frames are exposed and these are deliberately configured to express their loading with the flange widths slightly decreasing along the length of the span. Mies used principles of material economy, but usually in subtle ways such as this one. The roof structure below is covered by the suspended ceiling so that only the columns are visible from the interior.

This was a solution more expressive than functional, as there are a number of arguments for not inverting the structure in this way and simply letting the roof rest on the top of the frames. The hangers for the roof frames must penetrate the roof membrane, a possible source of leaks. The top chords of the trusses, which are in compression and subject to buckling, could have been braced by the small wide flanges that span between them, but the latter are attached to the bottom chords of the trusses, which are in tension. Reversing the arrangement by putting the frames inside, below the deck and wide flange, would of

Corner of Crown Hall To the left is the structural column one of the four major structural frame above. The other uprights are steel wide flange mullions supporting the glass.

Crown Hall. Window Mullions

Crown Hall. Window Mullions. Each function is given a separate elementstructure, glass structural support, and glass fastener.

course have rendered them invisible due to the ceiling. As is often the case in mature Mies buildings Crown Hall contains diagonal bracing, but in the roof where it cannot be seen.

Mies's ultimate concern was neither with function, nor with material economy in a strict sense. If he adapted the devices of those who practiced economy of materials-long spans, cantilevers, highly configured designs, he did so out of a desire for character and "style" rather than efficiency.

Despite the formal influence of the IIT Buildings, they were rarely imitated in their specific details, and for good reason. Although their technical standards were perhaps acceptable for 1940-1950, they are woefully inadequate by contemporary standards of maintenance and thermal performance. Uncoated steel frames exposed to the weather require frequent repainting and protection from rust. Walls, roofs, and foundations have no insulation and the numerous steel columns exposed on both the interior and exterior, form thermal bridges to allow heat to escape from the building. Although contemporary brick walls are still often monolithic, the IIT buildings if done today would in all likelihood be a cavity wall to provide adequate waterproofing and a space for insulation; the windows would certainly be double-glazed and the thermal bridges would be eliminated.

The standards of 1950 were different in regard to these questions, but if the IIT buildings were adequate by the standards of the day, they were certainly not on the cutting edge, and it is interesting to note that, even in those buildings that were the immediate progeny of IIT, details were altered to accommodate these problems. Eero Saarinen's General Motors Technical Center, although obviously inspired by Mies, uses a cavity wall, insulating glass and eliminates the thermal bridges.

Above: Farnsworth House, Plano, Illinois. 1951 Below: Porch at Farnsworth House. Note that the means by which the columns supports the porch is hidden.

THE FARNSWORTH HOUSE As the first academic buildings at IIT neared completion, Mies began work on his last significant and to many definitive single-family house. Despite being separated from the Resor house by only eight years, and despite similar programs and volumes, the two have little in common, and the Farnsworth house clearly picks up the direction pursued at IIT while establishing a new one as well, the principle of economy of material.

Mies’s previous houses had exposed no structure, cladding the columns in thin veneers and concealing the roof structure in thin flat wafers of the floors and ceilings. They owe much of their spatial and formal character to the structural properties of steel and concrete, particularly point supports and cantilevers, but the primary means of achieving these effects, the steel frame, was nowhere overtly shown. This is not to say that the Farnsworth house is the simple expression of its structure. Major beams and columns are shown, but minor beams, the diagonal bracing in the roof and the entire concrete structure, which is considerable, are hidden.

Myron Goldsmith, a key member of the office at the time, said that Mies saw the Farnsworth house as his best chance to build an exemplary steel structure with a minimum of compromise. For Mies this meant a different attitude toward joinery and it was an attitude that had wider consequences than might be expected. At the IIT Boiler house he had used exposed bolted connections. He clearly preferred welded joints, and in later buildings such as Crown Hall, there is a long visible filet weld where the face of the column meets the face of the channels at the edge of the slab. There are almost identical conditions at the column to floor and column to roof beam details at the Farnsworth house, but neither bolts nor welds are visible. The channel and I-shaped wide flange are connected by plug welds behind the column face and inside the hollow of the channel where they are concealed from view since they are buried in the floor construction. Given that there is no visible means by which the column supports the channel, this is a detail that denies rather than expresses construction, as neither the means of bearing nor the means of connection are visible. Clearly Mies saw this as a weightless abstraction, not a glorification of technology.

For a product of the industrial age the Farnsworth house contains a great deal of what can only be called handicraft. Because of the large number of field welds required, most of the structural steel fabrication was done on site. It would be difficult to find a steel frame building that is less industrialized and less prefabricated. Few components were "off the shelf," in the sense of being ordered from catalogues. The cabinets and paving slabs were all custom made. Because Mies refused to allow bolted connections, operations such as welding, cutting and sandblasting of the steel prior to painting had to be done in the field rather that in the shop.

The Farnsworth house introduced an old modernist principle to begin a new series of Miesian buildings-economy of material. Although he never used the more pyrotechnical devices of older constructivists and younger High Tech architects-elaborate cable

Farnsworth House Plano, Illinois, 1951

Center Bay, Farnsworth House The small white element at the center of the window originally a mullion, is also used as a tension cable to transfer loads from the heavy floor channel to the roof channel above.

suspended roofs, perforated beam webs, tapering beam sections, he did begin to use long span devices and to make extensive use of cantilevers.

The IIT buildings, except for Crown Hall, utilized almost exclusively simple span post and beam construction. Even the longer span buildings such as the Library used only larger wide flanges and no cantilevers. At the Farnsworth house Mies began to explore well-established modern ideas of economy, particularly the idea of equalizing the moments in beams by means of cantilevers.

One might argue that economy was not really the goal. The main channels are not only of constant depth but floor and roof channels are the same size, despite the differences in load between the two, primarily because of the heavy stone and concrete floor. The floor and roof beams that span between the channels are different sizes, but these are concealed above ceilings and under slabs. Mies was already using the deepest steel channel available, but even that proved inadequate for the load of the floor. As a result the vertical bars of the window mullions at midspan are employed as tension cables to take some of the load to the roof channel. For an architect who sought clarity this is as impure a detail as could be imagined, employing a non-structural part of the building in a structural way.

Clarity of structure was at times for Mies a question of appearance, not reality.

It is often pointed out how carefully Mies articulated the windows from the structural frame. The glass at Farnsworth is held in place by tees and rectilinear bars attached to the column and forming a reveal, clearly separating column from window frame. It should be noted how many of his peers and followers did not follow this practice. Craig Ellwood, Eero Saarinen and many others thought it more functional to use one element for as many purposes as possible, and often combined column and frame.

But if there is a fundamental principal of Miesian detailing it is the articulation of the specific element that solves the specific problem. The part the holds the glass, the part that supports the glass, and the part that supports the roof must all be just that, separate parts. If it is an approach that produces clarity it is also one that produces redundancy.

To the philosophically minded the reasons for this articulation and redundancy are clear.

Mies wrote in 1930: ‌ Things have their own life and dignity arising out of their intrinsic nature,.. There is a hierarchy of things, and they are not readily accessible but only if, in stepping in front of them, one is as they demand and assumes a position that relates to them.

To the hierarchy of objects corresponds a hierarchy of levels of perception on which the perceiver stands and on which he must stand if he wants to relate to the object. There is an awareness attitude assigned to each object‌. Much as there is a hierarchy of objects, there is a hierarchy of awareness attitudes.10 This is a principle that shows a remarkable similarity to that explored by Erwin Panofsky in Gothic Architecture and Scholasticism twenty-one years later in which Panofsky describes the discreet articulated parts of a Gothic cathedral as a parallel to the hierarchies and subdivisions of scholastic thinking. The other source of this concept is

Farnsworth House Left: Column to Channel Joint at roof.

Right: Column to Channel Joint at Floor.

Opposite: Columns at Porch Note the absence of bolts or exposed welds.

Left: Mullion and Edge Channel Connection, Crown Hall. Note the 45 degree fillet weld between wide flange and channel.

Right: Column and Edge Channel Connection, Farnsworth House. The channel is welded to the wide flange column with plug welds, circular holes filled with weld, on the inside of the channel where they are not visible.

architectural, not surprisingly classical and not surprisingly, Karl Friedrich Schinkel. His Schauspielhaus in Berlin appears a fairly monolithic stone building but it is articulated as a precise set of parts fulfilling certain discreet functions-large columns at the corners to support the roof, smaller columns supporting the openings of each window and infill walls set off by wide, deep reveals articulate the supported from the supporting. Mies commented in a 1959 interview on another Schinkel building: “Das Alte[s] Museum in Berlin was a beautiful building-you could learn everything in architecture from it-and I tried to do that…. [Schinkel] has separated the windows very clearly. He has separated the elements, the columns and the walls and the ceiling, and I think that is still visible in my later buildings.” 11 Many of the Mies-influenced buildings that followed the Farnsworth house did not have this quality. In Eero Saarinen’s John Deere Headquarters the glass is attached directly to the steel wide flange mullion with a neoprene gasket. No glass stop is used or needed. In Gordon Bunshaft’s Lever House a simple rectilinear steel shape supports and holds the glass. But if the Miesian principles of redundancy and articulation were abandoned by Mies’s immediate followers, the returned with a vengeance in the work of the High Tech architects in the 1980s.

As the Farnsworth House neared completion in 1950 Mies began a second residential project, the 50 x 50 house that carried the ideas of minimal material and optimum structural configuration a step further. The basic idea was the maximum cantilever, a square roof with four columns, but set at the center of each side rather than at the corner of a 50-foot square. The structural logic and “efficiency” of this arrangement is dubious.

Setting the columns at midspan does equalize moments in the beams, but at the expense of enormous torsion (twisting) around the column/beam connection and potentially excessive deflection at the ends.

Mies explored several framing systems for the house, and although no real architectural detailing was done, the steel sizes and total tonnage of steel were calculated in each case.

All save the last employed a square 4-foot grid of steel beams with deepened edge channels and various types of larger primary beams connecting the columns. One tapered the beam to reflect receding loads, a common device in modern architecture but rare in a Mies building. One put two columns on a side to create a miniature Crown Hall. Finally Mies employed a one-way system, probably to reduce cost.

Mies built no significant single-family houses after the completion of the Farnsworth.

Those designs that might have been significant went unrealized. Those that were realized were either row houses or houses that simply adapted the curtain walls of larger projects to simple one-story buildings. In the MacCormack house this was literal since it was built of extra components from the 860-880 Lake Shore Drive apartments.

Above: Eero Saarinen, John Deere Headquarters, Moline, Illinois, 1963 Below: Deere headquarter Curtain Wall. Neoprene gaskets connect the glass directly to the wide flange mullion, unlike the Miesian mullion with its articulated parts.

Gordon Bunshaft/SOM, Lever House, New York, 1952

Lever House, Curtain wall The mullions are constructed of thin Sheets of stainless steel wrapped around regular steel channels to form a rectilinear profile.

Left: 860-880 Lake Shore Drive Apartments, 1951. A steel framed building encased in concrete and clad with a steel curtain wall.

Right: Esplanade Apartments, 1956, with 860-880 Lake Shore Drive to the left. A concrete framed building clad with an aluminum curtain wall made with profiles similar to the steel ones at 860-880 Lake Shore Drive.

THE HIGH RISE OFFICE AND APARTMENT BUILDINGS Another of Mies's problems, one of his own making, was the difficulty of applying one constructional type to a variety of sizes and types of buildings. While eschewing the rigid standardization of a Gropius and Le Corbusier, Mies, like many modernists, wished to develop a singular, unified method of building, in his case the perfected steel frame, which could be applied to all sizes and types of buildings. The steel frame house was a particular obsession of the period. The American construction industry, by contrast, had evolved by 1960 into a fairly rigid organization in which certain constructional types were associated with certain building types-wood platform frames for detached houses, concrete frames for high-rise apartments, and steel frames for high-rise office buildings.

There were of course many exceptions to this, not all of which were created by architects going against the conventional wisdom.

Mies’s greatest difficulties in adjusting his idea of a universal system of building to specific types of program came in the apartment building. This is ironic, since 860-880 Lake Shore Drive is considered as one of his pivotal works and is the prototype, at least in imagery, for his later curtain walled buildings. The problem was simple: Mies’s aesthetic required a steel frame building clad in a steel curtain wall; the economics of building demanded, for this particular program type, a concrete frame building clad in brick and/or aluminum.

The logic of these construction types developed by the building industry, particularly that of the high-rise apartment building and the high-rise office building, had evolved into two distinct structural types. This is easily illustrated by two buildings which are superficially very similar: Mies’s office for the Toronto-Dominion , and Mies’s Commonwealth Promenade Apartments. The structure of the apartment building is a concrete flat plate with a typical bay size of 21 feet x 21 feet. The flat plate configuration is not as a rule the most efficient or economical way to build in concrete. The same volume of concrete, configured in to a ribbed slab, will span father and carry greater loads. In the case of an apartment, this is not always the economical solution. There being few ducts or lights to accommodate, no ceiling is required, and the flat plate offers a ready made fireproof ceiling with few restrictions as to interior partition layout, unlike a ribbed slab. The flat plate is limited to fairly short spans, 20-25 feet, a characteristic that would be a liability in an office building that requires large interior spaces, but this is not a major consideration in an apartment building and Commonwealth Promenade, again, does not exceed 21 feet.

The Toronto-Dominion Centre building, by contrast, has a steel frame with 30 foot x 40foot bays. This is a fairly standard size today but small in contrast to other Mies office buildings. The Mansion House office project has roughly 30 by 40 bays, but the Seagram, Chicago and Des Moines office buildings have bays roughly 30 feet by 30 feet. The modern office building is well suited to steel framing. Spans are longer than in apartment buildings, and due to the extensive requirements for ductwork and built-in lighting, suspended ceilings are usually required. The thin slabs of the steel frame buildings are more easily penetrated for the installation of communications, wiring, etc.

The floor-to-floor height between high-rise apartments and high-rise offices vary considerably. The Toronto office building has a ceiling to floor depth of 12 feet, a depth necessary to accommodate the structure, built-in lights, and extensive ductwork in an office building of this size. Commonwealth Promenade Apartments has no ducts; heat is distributed by a water system at the buildings perimeter. It has no built in lights, and thus has no suspended ceiling. Its structure is less deep than the office building being a slab 9 to 12 inches, the spans being shorter, and the floor-to-floor height is 9 feet. As a result although the apartment ceiling is only 10 inches lower than that of the office, the floor-tofloor height in the office building is up to three feet more than in the apartment. A threefoot difference in floor-to-floor height in a fifty-story building has major implications for the facade, both aesthetically, as it changes the proportions, and economically, as it increases the size and thus the cost of the building.

There are many, many exceptions to this typology. In Washington DC, due to its height restrictions, concrete framed office buildings are common. Since the floor-to-floor heights in concrete frames are less that in steel, an additional floor may be included within the limited building type. Certain types of concrete structures, the load bearing tube advocated by Falhzar Kahn for example, were used in many office buildings that exceeded 40 stories in height. But the above typology became for many the conventional wisdom. A development clearly illustrated by the history of the Miesian apartment building.

860-880 Lake Shore Drive is in some ways Mies’s purest creation, a steel frame building clad with a steel curtain wall, but it was in no way a constructional prototype for later apartment building construction. At the time Lake Shore Drive was built, this system was economical and competitive with a building system with concrete frame and brick infill.

According to Architectural Forum the building was 5 to 10 percent less expensive that comparable construction in Chicago.12 But this was no doubt an exceptional situation in postwar construction. Five years before 860-880 Lake Shore Drive, Mies’s first American apartment building, the Promontory Apartments, was designed on the model of steel frame and wall system of 860-880 Lake Shore Drive but economic conditions forced him to use a concrete frame with brick infill. Two years after Lake Shore Drive, Mies completed the Commonwealth Promenade Apartments. Commonwealth Promenade, and all subsequent Miesian apartment buildings, used concrete structural framing.

The great aesthetic virtue of the 860-880 Lake Shore Drive curtain wall is, as William Jordy has pointed out, that the multiple layers that exist within such a shallow space. The outermost layer is the parallel system of wide flanges that make up the window mullions.

These are superimposed on the second layer, a large grid of flat steel plates delineating the columns and beams. Filling the remaining voids is the third layer, aluminum windows with a clear, almost white finish, contrasting with the black painted steel.

These mullions need not have been exposed on the exterior, nor need they have been wide flanges. In fact the more typical glazed curtain wall of the day, of which there were not many in 1940, used rectilinear tubes, and placed the glass on the outside of the

Above: 860-880 Lake Shore Drive Apartments. Steel curtain wall showing rolled wide flange mullion. .

Below: Esplanade Apartments. Aluminum curtain wall showing extruded aluminum mullion.

mullions, as at Gordon Bunshaft's Lever House or Pietro Belluschi’s Equitable Building.

Belluschi and Bunshaft wanted to emphasize the taut skin-like quality of the glass membrane. This was, after all, skin and bones architecture. Mies’s solution is a more subtle one in which the mullion projects beyond the glass skin in order to create multiple layers, and which preserves something of the identity of the individual window opening framed by its white aluminum sash.

This brings us to the most famous wide flange in the history of architecture, the steel section that is welded to the column cover at 860-880 Lake Shore Drive. It is certainly one of the most controversial elements in Mies’s work if not Modern Architecture. It is of course structurally unnecessary, there being no glass to support. Peter Blake argued that it acts to stiffen the column cover. This is undoubtedly true, but the wide flange could hardly be structurally necessary. It should be recognized for what it is-ornament. The true mystery is why this particular element should be so controversial, given the wealth of purely ornamental wide flanges, not to mention ersatz wide flanges of aluminum in his previous and subsequent work. Entire facades of buildings at IIT are clad with ornamental steel frames, while in other locations steel columns are hidden behind brick walls. The answer is a simple one, Mies pointed out the ornamental nature of the wide flange at 860-880 Lake Shore Drive to the architectural press, who had probably never bothered to look closely at the published details of IIT that contains far more unnecessary and redundant steel than Lake Shore Drive.

As in all his work the desire to suppress the steel to steel joint is of primary importance, and most of the exterior joints are welded and ground smooth, as they were at the Farnsworth House and IIT, but the high rise building posed some special problems.

Normal procedure in high-rise construction is to minimize work in the upper levels of the exterior of the building, since this work must be done on scaffolding under dangerous conditions and in adverse weather. A typical solution today would be to divide the facade into panels that could be fabricated in the shop, delivered to the site, and lifted onto the building. A similar procedure was followed at 860-880 Lake Shore Drive, except that the assembly of the panels was done on the roof. (A curious procedure since it required that the structural frame be completed before work could begin on the facade.) The aluminum windows were then placed in the openings between the mullions. Just as in his other work Mies articulates the joint between dissimilar materials, aluminum windows and steel mullions, while rigidly suppressing joints between similar materials.

Just as the steel structure of 860-880 Lake Shore Drive proved inapplicable to apartment buildings, so did the steel curtain wall. Steel can require excessive maintenance because of its tendency to rust, and it tends to react electroliticaly with the aluminum window mullions, but a major problem is the lack of flexibility in fabricating window sections.

Structural steel sections are formed by rolling, and as a result the number of sections available is limited. The wide flange, I section, angle, channel, tee, and round and square tube make up almost the entire vocabulary. These sections are made in numerous sizes and weights, but due to the high cost of rolling, are rarely custom made.

Above: 860-880 Lake Shore Drive Apartments. Corner of steel curtain wall showing continuous welded joints.

Below: Esplanade Apartments. Corner of aluminum curtain wall showing notched interlocking joints.

Aluminum is lighter than steel, sometimes an important consideration in a large high rise building, less subject to corrosion, and the design of profiles is considerably more varied, as aluminum sections are made by extrusion, i.e., forcing molten aluminum through a die.

It is a process that facilitates the inclusion of integral thermal breaks reducing heat loss.

In fact at the time aluminum curtain walls were superior to steel in most technical ways with a notable exception; they have a higher coefficient of thermal expansion. Thus the great majority of curtain walls built between 1960 and 1995 have been aluminum. Steel, when used, is most often in the form of stainless steel. While equal in performance to aluminum, is much greater in cost. The principle virtue of the steel curtain wall is its visual. Steel curtain walls can use smaller mullion profiles that in turn give greater transparency. Mies clearly did not use it for this reason as his steel curtain walls are designed to be no more or less transparent than his aluminum ones. The Steel curtain wall was iconographic; it was made of the same materials and same configurations as the structure of the building, structures which could not otherwise be expressed, since they were concealed.

Thus it is not surprising that by the time Mies built the Esplanade apartments adjacent to 860/880 Lake Shore Drive in 1956, he had abandoned not only the steel structure but along with it, the steel curtain wall. But he did not see the aluminum curtain wall as an opportunity to explore a new material and its possible configurations. The Esplanade curtain wall is the steel curtain wall of Lake Shore Drive replicated in aluminum. This was the third of Mies’s American building types, the ornamental frame, similar in concept to the academic buildings at IIT, but with a much greater difference between the language of the exterior cladding and the actual construction of the building. When asked about the difference between these two types, he replied characteristically that either was acceptable, but that he preferred steel.

With this act, Mies attitude toward structural expression enters a new phase. It is one thing to cover a steel-framed structure with a representative cladding of steel. It is quite another to clad a concrete-framed building with an aluminum cladding imitating the forms of steel. In the Library at IIT, he expressed the steel structure by exposing it. At Lake Shore Drive, he built an analogous steel structure on the outside to describe the one that he could not expose. No such claim can be made for the Esplanade Apartments. It is a concrete structure clad with aluminum, and the forms of this cladding, while not inappropriate to aluminum, are specific to steel. This is not an analogous structure, but an ornamental one, unrelated to what it is cladding or to how it is made, perhaps recalling some ideal form of building that has been lost to history or is yet to be achieved. It was this system, not the steel system of 860-880 Lake Shore Drive that was to become the prototype for subsequent Miesian apartment buildings. The Colonnade Park (1960), Lafayette Square (1963), and Westmont Square (1968) and several others are all concrete frames with aluminum skins.

It can be argued that the I-shaped sections of the Esplanade are a perfectly reasonable, even a structurally expressive shape. The I shape of the steel wide flange is not only the result of the rolling process, but also acts to put the largest quantity of steel at the most important point, at its extremities. It is the flanges of the mullions that do the structural

work, not the web. At the same time, the I section is by no means the only section which has this characteristic. The rectilinear tube will work equally well, or a profile more expressive of the material, such as those used by Richard Rogers.

If the steel-framed apartment proved elusive in American building, the steel-framed office building became commonplace, but rarely clad with steel curtain walls. 860-880 Lake Shore Drive, an apartment building, succeeded completely as an image of the American office building. Unfortunately the design of American office building is often merely an advanced form of packaging, and the ideology and the technology of the 860880 Lake Shore Drive buildings were all too readily discarded. It was the image of Lake Shore Drive and not the reality that was to be influential, and the steel curtain wall was soon to become a rarity in high-rise curtain walls save for the use of stainless steel.

Almost all the large high-rise office buildings that Mies completed in the late 1950s and 1960s-Seagrams, the Toronto Dominion Cemter, the Federal Courthouse in Chicago, Charles Center in Baltimore, the IBM Building in Chicago-used steel frames. The problems of expression and connections of the steel framing that he faced in his houses did not occur here since the frames were in no cases visible, nor could they be, given the building codes under which they were built. An exception to this typology is Westmont Square in Montreal, which combines two twenty-one story apartment buildings with a twenty-two-story office building. Here both building types are framed with concrete waffle slabs, undoubtedly for economic reasons. All the structural work is in one material, concrete, and done by one contractor, an arrangement that is usually more economical. It did have consequences that were not advantageous. The apartment building required a continuous ceiling and the bay of the office building is one of the smallest of Mies’s buildings, 26 x 26 feet.

The Seagram building was completed in 1958, two years after the Esplanade Apartments, and the two curtain walls are surprisingly similar in appearance given the difference in program and material. The obvious differences between an office building and an apartment building-greater depth of the floor ceiling sandwich, a deeper spandrel, the absence of operable windows, seem to have had only minor effects on the design of the wall. What does make a considerable difference is the type of metal used. Seagram is not aluminum but bronze, a metal similar to aluminum but with some important differences.

Bronze can be extruded so the basic mullion shape is similar to the aluminum I, but the spandrel panels could not be made of bronze, so monel metal (an alloy of nickel, copper and iron) was used for these, and since the monel panel could not be welded to the bronze, they were mechanically joined in the field. The shop-welded panel system was thus impossible, and the Seagram wall is built by stick by stick, and while the joints are executed with considerable precision, there are a great many of them, many more than at Esplanade. At 860-880 Lake Shore Drive the steel mullion sat flat on the steel plate spandrel and column cover. At Seagram a batten and reveal are necessary to attach the monel metal panel to the mullion.

Although the Seagram building was enormously successful in the eyes of contemporary architects, it represented a very different animal from 860-880 Lake Shore Drive, and one

Seagram Building, New York, 1958

Bronze curtain wall.

One IBM Plaza, Chicago, 1970

Charles Center, Baltimore, 1962 Two steel framed, aluminum clad office buildings.

that was hardly a straightforward expression of technology, being a concealed steel frame building wrapped in a covering of imitation steel beams.

The external I section type curtain wall developed at Seagrams became popular and influential but it never replaced what was then and now the most popular profile, a simple rectilinear tube. This is similar in principle to the Seagram system consisting of a structural supporting tube and a cap (a pressure plate is usually added in contemporary versions) with the tube approximately the same width and depth of the I at Seagrams. The tube may be on the outside or inside according to taste and convenience of reglazing.

Typically these tubes are of aluminum, but Seagrams immediate neighbor, Gordon Bunshaft's Lever House, shows the tube system in a more elegant if more expensive form. The finish material is stainless steel, the ideal curtain wall material in terms of strength, maintenance, and durability, but also more expensive than aluminum. The solution here is a commonly used one, a structural tube of standard steel made from two channels is wrapped in a protective coating of stainless steel.

The Seagram's curtain wall has countless imitations but few of them are bronze. The typical solution was to give the aluminum a bronze anodized finish. An example of a better solution that avoids this rather deceptive imitation is also near Seagrams and also

by Bunshaft, the PepsiCo building, which uses a clear finished extruded aluminum I mullion similar to Seagram. PepsiCo's distinctive appearance comes from its mullion spacing, ten feet, twice the standard arrangement. While this impedes to a degree flexibility in partition layout, as the partitions are more easily aligned with mullions than flat glass, it gives the facade fewer visual divisions, more balanced proportions and a more comprehensible scale.

The Seagram's bronze curtain wall was expensive, and while it was proposed for the unbuilt Mansion house project in London, Mies never used it again. He may have been unhappy with the ornamental nature of the Seagram wall, i.e., that it imitated steel in bronze, and in subsequent buildings, such as the Toronto Dominion Center, he returned to a system similar to 860-880 Lake Shore Drive. Shop fabricated panels, consisting of steel wide flanges welded to steel spandrel panels were assembled on the structural frames, welded together and ground smooth. The portions of the frame holding the glazing however are not steel but aluminum, and are formed from extruded aluminum sections similar to those in Seagram. Thus the wall consists of a seamless steel grid, the openings of which are filled with aluminum frames to hold the glass separated from the steel by a reveal.

Although he revived the use of steel in a curtain wall in these two buildings, he did not return to the system of plates covering the structural frame used at 860-880 Lake Shore Drive, opting instead for the column detail used at Seagram, where the column is held back from the face of the glass and the column location is marked only by a typical mullion. He did consider the possibility of a steel facing frame covering the structure of the Toronto building, but was foiled by concerns regarding the temperature differential between the heated inside of the panel and the outside face that would be exposed to

Above: Seagram Building. Extruded bronze mullion and Monel metal spandrel panel.

Below: Toronto Dominion Center, 1967: Rolled steel mullion and steel spandrel panel with aluminum fixed window.

Toronto's extreme winter temperatures. Despite this effort, the Lake Shore Drive facade, with its steel mullions, seamless joints and intertwining of black steel and white aluminum, remains his finest curtain wall building, whatever its technical shortcomings.

CONCLUSION Mies’s post-Seagram buildings vary widely in interest. Most of the subsequent office and apartment buildings simply recapitulate the forms and techniques already established.

The progeny of Seagrams and Esplanade were in many cases dilutions rather than refinements of existing ideas. More compelling were his low-rise institutional buildings, where he continued to explore the ideas of material economy or perhaps material expression began at Crown Hall and the 50 x 50 house in increasingly larger buildings.

The external girders of Crown Hall, spanning 120 feet, grew into the 186-feet long trusses for the first design of the Home Federal Savings and Loan in Des Moines. The cantilevered roof of the 50 x 50 house became, with the addition of four more columns, the 180-foot x 180-foot Bacardi building (unbuilt) and finally the 212-foot x 212-foot Berlin Museum.

If this approach leads to more dramatic forms it often produced less functional results.

Although projects such as the National Theater in Manheim required its 266-foot truss, 120 feet is hardly a necessary span for an architectural school, 186 feet is hardly a necessary span for a bank lobby and the column free spans of the Houston and Berlin museums serve only to dwarf all but the most monumental art while defying spatial subdivision.

Mies’s aim with these long span buildings was neither material economy nor material expression, but rather the expression of architectural or even institutional importance. If the classical building demonstrated its importance by increasing its mass, Mies did the same by increasing the span. In Mies’s later buildings architectural significance is sometimes achieved through elaborate and excessive structural manipulation or as Robert Venturi and Denise Scott Brown would say, they are ducks.

Despite the idiosyncrasies of these exercises in overstrucuring they seem preferable to the alternative, the anonymous glass box. It is one of the great disappointments of Mies’s later work that he seemed to approach many building types as if they were speculative office buildings. One of his last groups of buildings, the Federal Center in Chicago, is composed of one large pavilion and two large office blocks, but the program, which contains courtrooms and jail cells in addition to offices, is hardly of the flexible speculative type associated with the modular type of curtain wall. In this case important aspects of the interior plans were known ahead of time, and in fact could only be fit with difficulty into the standardized, closely spaced mullioned envelope provided. In the case of several large courtrooms regular columns had to be eliminated to fit within the standard bay spacing. There is not even a hint of this on the exterior. Mies seems to be treating as problems issues he would formerly have regarded as opportunities, and it is hard to believe this building was designed by the architect of the Barcelona Pavilion and the Resor House.

Mies van der Rohe died in 1969. His last buildings demonstrate an interpretation of technology that is rather simple in relation to the work of other architects of the time-the integrated concrete structures of Louis Kahn, the technological imagery of Archigram

Above: New National Gallery Berlin, 1968 Left: Houston Museum of Fine Arts, 1958-1974

Above: Chicago Federal Center, 1959 Below: Chicago Federal Center, Post Office to the right , office buildings in the background and to the left.

and the work of the emerging High Tech movement. All of the latter saw structural expression as only one component of buildings that contained more complex mechanisms. But Mies disdained the articulation of mechanical and nonstructural elements to the end. He told Peter Blake in 1961: "I think structural elements are very essential elements, and I think that pipes are not. The structure can be integrated into architecture, but I don't think that pipes can."13 As for the legacy of the language he developed, it was a language of imagery more than of constructional reality. In the end he fell prey to the same trap as Le Corbusier.

Focused on developing al language of pure steel construction in which individual building types might be minor variations on a universal system, he failed to see that American construction was evolving in the opposite direction toward a greater diversity of constructional and program types. It was not becoming simpler and similar; it was becoming more complex and more diverse.

In some ways he was no different than Eliel Saarinen. His beliefs were influenced but not determined by his American experience, and his coolness toward industrialization was not warmed by proximity to its heartland. What he found in America was ultimately what he brought with him.

Above: Richard Rogers, Lloyds Building, London, 1984 Below: Lloyd’s Building, Curtain Wall Mullions The curtain wall is the external mullion type favored by Mies, but with a more modeled aluminum profile

Notes Epigraph Fritz Neumeyer, The Artless Word: Mies van der Rohe on the Building Art, and trans: Mark Jarzombek (Cambridge: MIT Press, 1991), 257.

1. Fritz Neumeyer, The Artless Word: Mies van der Rohe on the Building Art, and trans: Mark Jarzombek (Cambridge: MIT Press, 1991), 250.

2. Ibid., 261.

3. Ibid., 270, 288, 268.

4. Ibid., 245.

5. Arthur Drexler and Franz Schulze, eds., The Mies van der Rohe Archive, (New York: Garland), 1986.

6. Arthur Schopenhauer, The World as Will and Representation, Vol. 2 (Indian Hills, Colorado: Falcon Wing, 1958), 411.

7. Werner Blazer, Mies van der Rohe: The IIT Campus (Boston: Birkhauser, 2002), 75.

8. Ibid., 75.

9. Franz Schulze, Mies van der Rohe: A Critical Biography (Chicago: University of Chicago, 1985), 229.

10. Neumeyer, The Artless Word, 308-309.

11. Peter Carter, Mies van der Rohe at Work (New York: Praeger, 1972), 182.

12. _______,“Mies van der Rohe's New Buildings,� Architectural Forum 97 (November 1952), 96.

13. Columbia University. School of Architecture, Four Great Makers of Modern Architecture: Gropius, Le Corbusier, Mies van der Rohe, Wright (Da Capo Press, 1970), 98.

Bibliography Peter Blake, Mies Van Der Rohe: Architecture and Structure, New York: Pelican, 1966.

Arthur Drexler and Franz Schulze, eds., The Mies van der Rohe Archive, New York: Garland, 1986.

Charles Jencks, The Language of Post-Modern Architecture, Rizzoli, New York: 1977.

Franz Schulze, Mies van der Rohe: A Critical Biography Chicago: University of Chicago, 1985.

William H., Jordy, American Buildings and Their Architects: The Impact of European Modernism in the Mid-twentieth Century, Garden City: Doubleday, 1972.

Interview with Myron Goldsmith, May 1994 Interview with George Danforth, May 1994

POSTSCRIPT The bulk of this article was written in 1994, but I have updated, added and corrected information prior to posting it on the web. That said, including the addition of all subsequent developments would have required almost an entire rewriting. Welldocumented renovations of Crown Hall, Lever house and other buildings in the years since revealed a large number of problems not covered in this paper. At the same time the steel curtain wall has made something of a comeback in recent years. The legacy of what I called the articulation and autonomy of parts in Mies’s detailing has waxed and waned in the years since. It saw its apogee in the work of the High Tech architects Richard Rogers and Peter Rice in particular. In the last ten years architects such as Herzog and de Meuron have gone to great lengths to eliminate such hierarchies.