House VI
Peter Eisenman, architect
Location
History
In order to understand the structural system of House VI it is necessary to know the theoretical context in which the building was designed and constructed. While not a model of great clarity and structural honesty, it represents and efficient method of
construction. This house is constructed using primarily a post and beam system, with box beams and large dimension timbers forming the major elements of the structural system. The building is a study in the relationships between the actual structure and
the architectural theory. Many of the forms that appear structural are actually included to reinforce the concepts behind the design. In his critique of the house, Robert Gutman wrote, "most of these columns have no role in supporting the building plan
es, but are there, like the planes and the slits in the walls and ceilings that represent planes, to mark the geometry and rhythm of Eisenman's notational system." 1 It was not Eisenman's intent to convey the actual structure, but rat
her to allow the system to define a module, which is augmented by additional space defining forms.
Physical Description
Because the house is located in an area which experiences severe winters, the structural system begins with the poured concrete foundation walls and footings several feet below grade. A double mud sill is secured to the tops of the foundation walls with
anchor bolts embedded in the concrete. This continuous sill forms the basis of the connections between the post nad beam system and the more traditional platform style framing supplementing it. The columns rest on the sill and the rim joists secure them
to the rest of the framing. As the organization of the house is based on a modular system, many of the openings formed by the posts and beams are infilled with stud walls. Together with the wall sheathing, the framing acts as a shear wall, giving the s
tructure lateral stability. Because there are numerous openings and windows that occupy the entire module of a post and beam unit, the distribution of the shear walls throughout the structure is essential. Certain portions of the house are cantileverd o
ut from the outer planes of the exterior and present special structural problems to be considered. Here, iron diagonal members function in tension to support the cantilevers which are framed as a part of the platform system. The same iron diagonals can
be found in walls that are too thin to accommodate stud framing to act as a shear wall. In walls where a "slit" window is located, diagonal bracing takes up the spaces on each side of the window. Some walls of the house are located outside of the rim jo
ists and corresponding foundation walls. These are supported by steel angle brackets bolted to the rim joists forming their own platform for the wall to sit on. Plywood sheathing covers the exterior of the house, continued around the posts and beams in
a gesture that allows some of the structural method to be seen.
Building Process
Structural Descripton/Aspects
Vertical Loading
The general principles of a post and beam building system are relatively simple and easy to understand. Peter Eisenman exploited these principles as a means of creating open spaces and large glazed openings to further his design principles. With a basic
understanding of the post and beam system, one can begin to see the ways that vertical loads are distributed throughout the structure.
The amount of primary and secondary loads that a member has to resist is directly related to the size and shape of the cross-section of that member. For this reason, some beams and columns are larger than others. The most obvious of this application is
the doubled columns at the center of the house, those with the largest tributary area and loads. Both live and dead loads need to be accounted for in the sizing and design. Therefore, the roof members are smaller as they have a relatively small tributar
y load and only snow loads to accommodate. Moving closer to the ground, the members increase in size, taking into account the larger tributary load as well as the introduction of greater live loads.
Assuming that someone were to place a load on the roof that fell above a typical beam, the load pattern would be as follows. The load would put the beam in bending, with the beams ability to resist relating to the amount of resistance that a shear wall o
r diagonal bracing must exert to counter the bending caused by the downward load. The purpose of the bracing is to keep the vertical forces of the load acting in a downward direction through the columns, rather than redirecting them into an additional ho
rizontal component. The columns that are continuous from the roof plane to the foundation translate the load directly, while some rely on the distributing characteristics of the platform framing to keep the loads directed downward.
Lateral Loading
House VI resists lateral loading through means that are relatively typical for a wood framed, residential scale building. Lateral loads are distributed through a combination of shear walls, diagonal bracing, and a construction method integrating post and
beam and platform framing. As an evenly distributed lateral force (i.e. wind) is applied against an exterior wall, the forces would be distributed by this integral method of construction. The lateral load will cause bending in the wall, which would be
resisted by the method of lateral bracing in that portion of the building. As discussed earlier, certain types of lateral bracing are included to accommodate special design considerations for certain parts of the house. With lateral bracing, the forces
begin to act on the edge of a plane, attempting to overturn it. Because of the open nature of this structure, this transformation occurs on the scale of the entire building, rather than individual bays.
Whatever device is used for lateral bracing, the forces are redirected into vertical loads at the columns. These vertical loads may be upward or downward, depending upon which edge of the wall is being examined. Upward loads are counteracted by the anch
oring of the entire framed structure to the foundation and ultimately relying on the mass of the foundation to hold the building down. Downward loads rely on the compressive nature of the posts, foundation and earth. The diagonal bracing in the building
is not connected to the foundation in any way. This reinforces the idea that this building is braced as a unit and treated as a whole. The bracing transfers the uniformly lateral load to a beam. The beams take this load and apply the load horizontally
to the main columns. The columns transfer this horizontal load vertically to the foundation wall, which distributes the load to the ground.
Conclusions
Bibliography
- Frank, Suzanne. Peter Eisenman's House VI. New York: Whitney Library of Design, 1994.
Associated Buildings
Nathan Roelofs and Ethen Wood
ARCH 461/561 Spring 1995
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