Oakland International Airport Extension
Architect: HOK Architects
Location: Oakland, CA
Status: Schematic Design

The expansion of Oakland International Airport replaces the existing Terminal 1 with a new entrance lobby and security area along with ticketing and departure wings. The grand lobby consists of three stepping volumes primarily defined by cascading roofs, each supported by four interior columns. The curtain wall emphasizes the "floating" roofs with a wall of opaque metal panels that give way to a continuous glass clerestory. The monumental volume flows down from the east-facing arrival hall, through a set of security gates, to a concession area that marks the intersection of the two main departure wings. The culmination of the architectural experience occurs at the west facade, where a wall of glass provides views to the runways beyond. The ticketing and departure wings are canted 45¡ from cardinal and face all four orientations. The architecture of floating roofs continues at a modest scale and the transparent glass facades orient occupants to the jetways and airplanes as well as the passage of time and local weather conditions.

The challenges of this project which we addressed with the design team consist of balancing visual and thermal comfort, as well as energy use, with an aesthetic of glass and transparency. Different comfort requirements and associated mechanical and architectural strategies were recognized and identified for different areas of the airport: localized air conditioning, exterior horizontal shading devices and overhangs, interior light shelves, interior blinds, high technology glass, localized use of interior canopies, and dynamic shading using mechanical devices or specialty glass. In addition, a parametric analysis of glare conditions in the ticketing and boarding wings led to the study of various skylight and clerestory configurations. Changing patterns of direct beam radiation were modeled and studied using 3-D Studio and animated renderings. Quantity and quality of interior light conditions were predicted using Radiance. Cooling loads resulting various glass configurations, specifications, and shading conditions were parametrically modeled using DOE-2.1e.

We worked closely with the mechanical engineers to develop an air conditioning strategy for the entrance lobby that would deliver air only where people would be present rather than normatively conditioning the entire volume. At the same time, methods of maintaining transparency and views while blocking direct beam solar radiation were studied. Horizontal shading devices were recommended for the east entrance and ticketing and boarding wings; however, at the west end of the lobby, the focal point of the design, a more dynamic solution is desirable. An art installation, either integrated with the curtain wall or outside of it can also act as a controllable shading device to allow views for most of the day, but to block the late-afternoon sun.

Parametric Radiance runs illustrated that glare caused by severe luminous contrast in the ticketing and boarding wings could be avoided by using several strategies. Interior light shelves can reduce areas of high contrast by reflecting light onto the ceiling while minimizing views of the bright sky. Diffusing operable blinds can also modulate the bright sky while providing maximum occupant control. A custom advanced glazing including spectrally selective film, tint and fritting is specified for use in the lobby as well as the wings. Given the large areas of glazing, this reduces light transmission sufficiently to produce a luminous environment of lower contrast while also minimizing heat gain caused by solar radiation. Interior canopies, particularly at the ticketing counter and security gates, will provide localized shading for tasks which would require a high degree of visual discrimination, as well as shade for sedentary areas in the holding areas. Radiance renderings of skylight and clerestory configurations for the airport wings illustrated both quantitatively and qualitatively the advantages of balancing the intense unilateral delivery in the holding areas. We also recommended that the amount of glass, particularly in the boarding areas, be reduced to generate seating some areas of shade and some of sun. This strategy would also mitigate the radiant assymmetry caused by direct beam radiation particularly in the northwest and southwest boarding areas.