Frost Amphitheater Renewal

Stanford University invited James Carpenter Design Associates (JCDA) to a redevelop the Frost Amphitheater, built in 1937. The goals were to envision a new canopy to provide shade and protection for 2,500 seated patrons and to renew the stage, back of house, entries and circulation.

JCDA’s approach is founded on preserving the integrity of the site, a six-acre man-made bowl and open air forum with a powerful sense of the sky. A minimal and elegant intervention, the Sky Reflector Canopy, developed with Schlaich Bergermann and Partners, is a lightweight tensile structure with a deployable roof canopy, buoyantly suspended within the site’s topography and natural setting.

Matching the site's topography, the uplifting double curved cable-net form welcomes visitors and accentuates the stage as a point of focus. The translucent fabric canopy is deployed along the cable-net’s fanning array of longitudinal cables, providing shelter from sun or rain and enhancing the amphitheater’s existing micro-climate.

When the canopy is retracted, sky reflectors set parallel to the stage become visible above the net’s transverse cables. When viewed from the rear of the amphitheater’s bowl to the south, these arcing linear reflections visually stack together to create a wide periscopic view of the northern sky. As viewers descend toward the stage, the reflectors and structure almost disappear. This powerful poetic light effect, suspended between earth and sky, is in constant dialog with the changing atmospheric conditions of the outdoor environment.

In merging art, engineering and an environmental approach to place making, the Sky Reflector Canopy is an innovative architectural instrument that celebrates this extraordinary site’s character, a site that transforms academic and social rites of passage into experiences vividly remembered by generations of students and alumni.

Technical Information:

CELEBRATION OF SKY AND NATURAL SURROUNDINGS
1. Maintains the character of the Amphitheater and touch it as lightly as possible
2. Maintains an all-grass Amphitheater
3. Allows openness to the sky - maintain the landscape/sky relationship
4. Allows openness on all sides to connect to the landscape from all vantage points
5. Suspends the roof between earth and sky
6. Sky reflectors transform the delicate structure into a poetic expression of shifting atmospheric colors, both day and night

LIGHTNESS
1. Has the lightest and most transparent structure
2. Has a gentle, fluid, singular shelter for BOTH stage and seating area
3. Has a welcoming form that embraces the bowl
4. Has optimal/minimal stage framework for maximum flexibility for events

ENVIRONMENTAL
1. Provides sun and rain protection plus environmental control to extend the seasonal use of the Amphi¬theater by several months
2. Provides a deployable roof that can be tuned to existing environmental conditions
3. Deployable roof environmentally controls the thermal comfort of the bowl: cooler in summer and warmer in winter
4. Canopy can be used by Stanford University’s Woods Institute to engage students in environmental data collection of the bowl to devise and program the active use of the deployable roof to improve thermal comfort
5. Maintains and enhances natural breezes within the bowl
6. Maintains balance between comfort and openness
7. Produces an enclosure/roof that is specifically unique to this Stanford site and environment
8. Produce an enclosure/roof that is both innovative yet based upon proven technology and materials

MATERIALS
1. Uses only the most durable and proven materials
2. Primary structure stainless steel cables and Galvan cable and carbon steel masts
3. Tenara fabric: 20 year factory full replacement warranty, projected operable life 40+ years
4. Mechanical system: following manufacturers maintenance procedures: indefinite
5. JCDA/Schlaich Bergermann optimize the design of the foundations and minimize impact on landscape to assure economy
6. Primary cost of Sky Reflector Net is the permanent cable net structure and foundations (80% - 90%).
7. Fabric and mechanical system is a minor percentage of overall cost

Refer to Axonometric for retractable cable-net canopy details.