When Chicago hosted the 1933 Century of Progress World’s Fair, the city was an example to the world of advances in modern living and architecture. Indeed, it showcased the “architecture of the future” through the fair’s central theme, “Science Advancing Mankind,” and the work of noted architects Raymond Hood, Paul Cret, George Fred Keck, Edward Bennett, Hubert Burnham, Daniel Burnham Jr., John Holabird, Nathaniel Owings, Joseph Urban and Louis Skidmore. Today, Chicago continues to be a leader in technological advances by incorporating new technologies in architectural design. For example, BankOne Corporate Center (formerly Dearborn Center) and the ABN AMRO Plaza — both commercial office buildings — have extensive technology such as raised floors and systems integration.

Building systems concepts must be selected, developed and refined to achieve the most effective balance of first costs, life cycle costs and occupant comfort. Today’s buildings must cater to dynamic, fast-moving clients with a demand for fast-growing technology. Buildings must provide services for communications technology and be able to create a flexible tenant environment. In addition, communication cable installation and management must be accommodated in the base building to minimize tenants’ construction time and installation cost during initial fit-out. Systems also must be flexible and allow for complete furniture and office reconfiguration with minimal disruption of other functions.

The use of raised-floor pressurized plenum air supply systems is a benchmark of technological advances in 21st century commercial architectural design. First developed in the 1950s, raised-floor systems were used predominantly for localized computer room installations to respond to concentrated equipment loads, increased ventilation requirements and extensive wiring distribution networks. As communication systems and related data technologies further evolved, raised-floor systems were, in a sense, “reinvented” to embrace the emerging integrated systems’ needs in architectural and engineering design. Although the raised-floor system has stayed fundamentally the same since its introduction in the mid-20th century, technological developments of the past 20 years have led the industry to the logical integration of ventilation air, computer, communication and information technologies into one common physical space.

These installations, which were first used extensively in corporate office buildings in Europe, have provided the foundation for long-term case studies of raised-floor systems. Despite initial resistance to these systems throughout commercial office space in the United States, the trend took hold in North America in the last decade. Under-floor systems are now recognized as offering the combined opportunity for integrated information technology network distribution and environmental air conditioning. This shift from a traditional overhead HVAC ceiling distribution system to the raised-floor method — and the inherent benefits of this alternative functioning system — are now being recognized by large corporations seeking the advantages of a fully flexible workspace.

The raised-floor system provides advantages to the operational comfort and efficiency of the building ventilation systems, such as improved air quality, reduced energy consumption, temperature control and lower initial costs, all of which also benefit the owners, current and future occupants, and employees. These benefits help to create a better working environment by increasing the number of air changes in the workspace for greater occupant comfort. The system optimizes operational efficiency by reducing the supply air temperature differential, using lower temperature and pressure, and constant volume blended air, which also reduces cold drafts. Each occupant/workstation has his or her own floor diffuser that can easily be adjusted to satisfy each occupant's own temperature preference and local equipment heat load. The use of lower temperature and pressure, and a constant volume system, also leads to less energy consumption, more efficient equipment and less plant area, all critically important objectives in sustainable design, which is becoming increasingly more important in urban design as well as in local, state and federal planning.

Probably the greatest attraction of the raised floor is systems integration — the opportunity to use the plenum space for the distribution of other systems such as low voltage data and signal cabling, line voltage and network wire management systems. An equally appealing advantage of the system is tenant flexibility because it is composed of almost infinitely adjustable components that can be reconfigured to the ever-changing office environment. The floor system consists of 2-foot, square interlocking floor panels supported by pedestals that are anchored to the base floor slab. Each floor panel can be interchanged with another to allow precise positioning of diffusers and floor service modules to facilitate the tenant’s requirements. This adaptability is particularly beneficial to corporate tenants using large floor plates.

Office floors are also bigger when using this design. The absence of overhead ductwork distribution allows for a reduced ceiling plenum depth, which results in higher ceilings and/or reduced floor-to-floor heights, all relating to a better work environment and lower hard costs. Floor-to-ceiling windows, such as high performance, low-emissivity coated glass products, can also be installed at the building perimeter to increase the effect of natural lighting on these large floor plates.

The architectural industry continues to become more sophisticated as clients’ needs become more technologically advanced. Clients are seeking advanced systems integration and, as a result, architects must look to achieve a balance between costs and the adaptability of building systems.

Raymond Clark is president of Chicago-based DeStefano and Partners.

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