Project Details
- Project Name
- Chicago Horizon
- Project Types
- Cultural
- Project Scope
- New Construction
- Shared by
- Hanley Wood Media
- Team
-
Yasmin Vobis
Aaron Forrest, AIA
Structural engineer: Brett Schneider
- Project Status
- Concept Proposal
This winning concept in the Chicago Architecture Biennial Lakefront Kiosk Competition was awarded the BP Prize, which includes a $10,000 honorarium and $75,000 for construction of the kiosk. The kiosk opened in October 2015 with the opening of the biennial.
Project Description
FROM THE ARCHITECTS:
How much
kiosk can you get for $75,000? Chicago Horizon probes this question through a
quest to build the largest flat wood roof possible. Using Cross-Laminated
Timber, a new carbon-negative engineered lumber product, in the largest
dimensions commercially available, the kiosk aims to provide an excess of
public space for the Architecture Biennial and Chicago beach-goers. The
generous 56-foot square offers an architectural lending library and shelter
from the elements during its time in Millennium Park, and later becomes a large
shading canopy overlooking Lake Michigan with space for commercial vending
within. Chicago Horizon expresses lightness at a variety of scales, from the
8-foot hovering roof plane to the viewing platform and vending kiosk, which are
suspended from the roof using chain-link fencing without any additional
supports. The lateral reach of the roof recalibrates the experience of two
extremes of the Chicago landscape: at ground level, the Lake Michigan horizon
dominates, forming a line of symmetry between ground and canopy. From the
viewing platform, the roof becomes a new artificial horizon, shutting out the
foreground and emphasizing the floating vertical Chicago skyline above an abstract
floating plane.
The
program of the kiosk is formulated around its multiple contexts: the Chicago
Architecture Biennial, the Lake Michigan beach, and, of course, the city of
Chicago. During the Biennial, it will house an architectural lending library,
designed both to facilitate the free exchange of books and as a venue for the
exchange of new ideas: the large canopy extends well beyond the library
enclosure, offering space for talks, events, and discussion, and for fair-goers
to take refuge from the elements. Once the kiosk has been relocated to the Lake
Michigan beach, the library transforms into a space for commercial vending, and
the roof offers as much protection from the summer sun as it does from rain and
snow. The lockable fence enclosures provide a secure environment for the
library and commercial vendor alike, while also offering the potential for
chair storage beneath the viewing platform.
At night
the chain-link enclosures double as a lighting installation, each outfitted
with a plane of programmable LED lighting and glowing with a different color
temperature. The two pulsate in dialogue with each other throughout the night,
alternating between the two poles of experience that the design sets up:
ceiling and floor, day and night. LED strip lighting integrated into the
fencing is used as signage for both library and commercial vendor.
Chicago
Horizon is constructed almost entirely out of engineered timber products,
including CLT for the roof canopy and glulam columns, making its total carbon
impact negative due to the ability of wood to sequester atmospheric carbon. The
canopy is to be fully protected by a roof membrane and an exterior grade
plywood deck, ensuring its longevity. Interior enclosures are made from
galvanized steel chain-link fencing, with steel grating for the viewing
platform and wood shelving in the library enclosure. The fencing is suspended
in tension from the canopy, providing the sole means of support for the
platform and shelving. The kiosk emphasizes ease of construction, with most
components fabricated off site and installation complete within a matter of
days. The roof is constructed from the largest CLT panels commercially
shippable in North America, and is assembled on the ground and hoisted up on
glulam columns set on temporary helical pile foundations. Once the Biennial is
complete, the roof can be lowered again and transported as a single piece the
short distance to its final home on Lake Michigan.
Structural Narrative
The
pavilion roof structure represents the application of the principles of flat
plate (typical to concrete construction) to the material of wood. Two layers of
CLT panels—one layer oriented in each principal direction, and each outer layer
oriented lengthwise to the 8-foot-wide by 56-foot-long panels—combine to form a
two-way spanning plate supported at points by columns. Each layer carries
bending in the direction of the panel, with the layer above or below providing
shear transfer between adjacent panels (and vice versa in the other direction).
The result is a surprisingly thin 8.25-inch roof structure that spans upward of
30 feet between columns.
The
columns connect to the roof plate using steel tongue plate bolted to the
columns, which passes up through a slot in the CLT to a horizontal plate that
connects to the CLT panels from above, hidden below the roofing and
waterproofing. The columns themselves are simple glued laminated sections, held
off the ground by a similar tongue plate at the base. The observation platform
is supported by a chain-link fence held in tension along the edge of the
opening to the roof using tack welds to structural steel angle framing the
opening. The overall system is simple in its detailing, use of materials, and
conception of its performance as a two-way plate, and this underlying
simplicity complements the efficiency of the system.