Physical Integration

Building components have to fit. They share space and volume in a building, and they connect in specific ways. CAD drawing layers offer a useful way to think about how complicated these networks of shared space and connect­ed pieces can become. Superimposing structure and HVAC (heating, ventilating, and air-conditioning) layers provides an example: Are there problems where large ducts pass under beams? Do the reflected ceiling plan and furniture layouts put light fixtures where they belong?

Physical integration is fundamentally about how com­ponents and systems share space, how they fit together. In standard practice, for example, the floor-ceiling section of many buildings is often subdivided into separate zones: recessed lighting in the lowest zone, space for ducts next, and then a zone for the depth of structure to support the floor above. These segregated volumes prevent “interfer­ence” between systems by providing adequate space for each individually remote system. Meshing the systems together, say, by running the ducts between light fixtures, requires careful physical integration. Unifying the systems by using the ceiling cavity as a return air plenum and extracting return air through the light fixtures further compresses the depth of physical space required. If the structure consists of open web joists, trusses, or a space frame, then it is possible that all three systems may be phys­ically integrated into a single zone by carefully interspers­ing ducts and light fixtures within the structure.

Connections between components and among sys­tems in general constitute another aspect of physical inte­gration. This is also where architectural details are generated. The structural, thermal, and physical integrity of the joints between different materials must be carefully considered. How they meet is just as important as how they are separated in space.

Visual Integration

Exposed and formally expressive components of a building combine to create its image. This is true of the overall visu­al idea of the building as well as of the character of rooms and of individual elements, down to the smallest details. The manner in which components share in a cumulative image is decided through acts of visual integration. Color, size, shape, and placement are common factors that can be manipulated in order to achieve the desired effect, so knowledge of the various components’ visual character is essential to integrating them.

Visual harmony among the many parts of a building and their agreement with the intended visual effects of design often provide some opportunities for combining technical requirements with aesthetic goals. Light fixtures, air-conditioning, plumbing fixtures, and a host of other elements are going to have a presence in the building any­way. Ignoring them or trying to cover them with finishes or decoration is futile. Technical criteria and the systems that satisfy those functional demands require large shares of the resources that go into a building. It follows that architects should be able to select, configure, and deploy building elements in ways that satisfy both visual and functional objectives.

Performance Integration

If physical integration is “shared space” and visual integra­tion is “shared image,” then performance integration must have something to do with shared functions. A load-bearing wall, for example, is both envelope and structure, so it uni­fies two functions into one element by replacing two columns, a beam, and the exterior wall. This approach can save cost and reduce complexity if it is appropriate to the task at hand.

Performance integration is also served by meshing or overlapping the functions of two components, even with­out actually combining the pieces. This may be called “shared mandates.” In a direct-gain passive solar heating
system, for example, the floor of the sunlit space is sharing in the thermal work of the envelope and the mechanical heating system by providing thermal storage in its massive heat capacity, which limits indoor temperature swings from sunlit day to cold starry night. The envelope, structure, inte­rior, and services are integrated by the shared thermal man­date of maintaining comfortable temperatures.

Integrating Integrations: Louis Kahn and the Kimball Art Museum

The three modes of integration among systems are fre­quently interwoven, so it is difficult and probably unnec­essary to label every act of integration as either physical, visual, or functional. The previous example of physical integration in a floor-to-ceiling section among lighting, ductwork, and structure also has important performance benefits if the lighting fixtures are used as return air regis­ters and the plenum is used as a return air path. In addi­tion, combining the lighting and return air register func­tions within the light fixtures simplifies the aesthetic of the room’s ceiling. Most components of a building have phys­ical, visual, and functional impacts; it is likely that one sort of integration will involve other sorts.

For an example of how these forms of integration can be combined, consider Louis Kahn’s design for the Kimbell Art Museum. The synthesis of major systems is characterized by unification and meshing among struc­ture, envelope, services, and interior systems and is embodied by the repeated use of an elegant concrete vault. This one element is both structural support and envelope enclosure. It also forms the interior space. Finally, by virtue of its cycloid ceiling shape and skylit ridge, its func­tions are meshed with the important services mandate of lighting a space for artwork. The physical, visual, and per­formance benefits are complete and convincing. The sys­tems go beyond being minimally resolved; they are synergistic to the point of being provocatively elegant. It would be trivial to worry about their exact classification.