Aqua towers

NAME : AQUA TOWER, LAKESHORE EAST BUILDING 2-P
EBN, 190323

usage –
residential; condominium; hotel; rental apartments
• Side usage
parking; commercial office; shop(s)
Built – 2007-2009
Cost – US$300 million
Owner – Aqua Realty Holdings LLC
Floor count –
82
1 below ground
Height – 859 ft (262 m)
Floor area – 1,990,635 sq ft (184,936.0 m2)
Lifts/elevators – 24
Number of apartments – 739
Number of hotel rooms – 215
Number of parking spaces – 1557
Architect
Jeanne Gang of Studio Gang Architects
Developer
Magellan Development Group
Structural Engineer
Magnusson Klemencic Associates
main Contractor
James McHugh Construction Co
Aqua is an 82-story mixed-use residential skyscraper in the Lakeshore East
development in downtown Chicago, Illinois. It is designed by Jeanne Gang ,
principal and founder of Studio Gang Architects, and it is her first skyscraper
project. This is the largest project ever awarded to an American firm headed by a
woman. Loewenberg & Associates are the architects of record, led by James
Loewenberg. Each floor covers approximately 16,000 sq ft (1,500 m2). The Aqua
was named the Emporis Skyscraper Award 2009 skyscraper of the year, and was
shortlisted in 2010 for the biannual International Highrise Award.

contains 55,000 sq ft (5,100 m2) of retail and office space,
in addition to 215 hotel rooms (floors 1-18), 476 rental residential units
(floors 19-52), and 263 condominium units & Penthouses (floors 53-81).
Aqua is the first downtown building to combine condos, apartments and a
hotel.
• To capture views of nearby landmarks for Aqua’s residents, Gang
stretched its balconies outward by as much as 12 ft (3.7 m). The result is
a building composed of irregularly shaped concrete floor slabs which
lend the facade an undulating, sculptural quality.
• A daring piece of architecture for The Loop area, Aqua comes off more as
a massive sculpture than as a residential block in the crowded heart of the
city. The name ‘Aqua’ fits the nautical theme of the Lakeshore East
development, and is derived from the wave-like forms of the balconies.
The name also matches the blue-green tint of the windows.
• Aqua is a daring new addition to the Chicago skyline.

utilized in both the structural support and the tower’s
architectural expression.
• The tower’s façade features vertical glass with undulating balconies of
reinforced concrete that varies slightly from floor to floor, creating a
rippling, wavelike effect. Overall, the exterior mimics the natural striated
limestone outcroppings and formations that are plentiful throughout the
Great Lakes region.
• The sinuously curved concrete decks on each floor assume different
configurations where balconies extend anywhere from 2 to 12 feet.
Although the architects used computer modeling to create the rippling
contours, the fact that each floor slab is unique in shape meant
calculations had to be done separately for each floor.
• At the base of the tower, a three-story podium contains the hotel and
apartment lobbies, the hotel ballroom, and other public rooms. But the
coup de théatre is the 80,000-square-foot podium roof garden, with an
outdoor swimming pool and a running track. In this park-like roof,
meandering paths weave between low evergreen plants and deciduous
plantings that may not be native but generate a “geometric naturalism,”.
• Aqua is an amazing tower demonstrating how concrete can be creatively
applied to achieve both outstanding architecture and a durable structure.
• Residents and visitors of the Aqua Tower are able to occupy the building
while retaining the sense of also being a part of a metropolis at large.

floors are 16,000 square feet and offer spectacular
views of Lake Michigan, the Chicago River and some of Chicago’s
architecture gems.
View of Lake Michigan/ Navy Pier
View of neighborhood park
View of Chicago RiverView of Millennium Park

of Studio Gang, had not designed a high-rise structure (not to
mention a sustainable one) before Aqua, the 82-story tower in Chicago’s
downtown. Her small 38-person firm, in business in the city since 1997, had,
however, distinguished itself with community centers, schools, and houses. Then
in 2004 she met developer and architect James Loewenberg of the Magellan
Development Group, who is behind the 28-acre Lakeshore East mixed-use
complex, which has been under construction on the old Illinois Central Railroad
yards along Lake Michigan during much of the last decade. Loewenberg asked
Gang to come up with a fresh design for a new 1.9 million-square-foot structure in
Lakeshore East, for which he would be both the client and the executive architect.
Now the $300-million (construction) residential tower, which rises from a podium
on the 179,946-square-foot site near Millennium Park, has just been completed. In
a city known for its rectilinear Miesian skyscrapers, Gang brought back the curve
by wrapping her residential tower with sinuously swerving concrete balconies.

–
residential; condominium; hotel; rental apartments
• Side usage
parking; commercial office; shop(s)
Access
• The building has its main access from North Columbus Drive.
Porch
Sapphire neon illuminates
The entrance of Radisson
Blu Aqua hotel. The azure
lighting drives home the
branding of the hotel. Blu is
the luxury offshoot of
Radisson Hotels, once known
for reliable, staid, moderate
hotels.

orientation of the building maximizes exposure in winter, facilitating
passive heating.
• The balconies on the south facade are deliberately larger to reduce exposure in
summer.
• In addition to low e-coating on all glass, the design team modeled seasonal sun
patterns to identify areas requiring additional glazing in order to increase the
tower’s energy performance.
• Glass on the east and south façades are reflective in areas without a protective
balcony, while glass facing west has a tinted coating that improves its shading
coefficient.
• The undulating slab edges disrupted or “confused” the flow of wind around the
tower, effectively reducing the wind demands, and this, combined with the
effectiveness of the structural design, eliminated the need for a supplemental
damping system.
• Much of the exposed glass is fritted, not only to help reduce heat and glare, but,
along with dark gray aluminum balustrades, to keep birds from crashing into the
tower. Already this strategy won Aqua a Proggy award (named for “progress”)
from the People for the Ethical Treatment of Animals.
• At the base of the tower, a three-story podium is topped with the 80,000-square-
foot podium roof garden. . The roof’s vegetation is not only aesthetic but also
combats the heat- island effect during the hot summer months by lowering ambient
temperatures around the building.
N

A
major tourist spot of the
city.
82 – STOREY
AQUA TOWER
3 – STOREY PODIUM
with 80.000 sq.ft. roof
garden
SWISSOTEL
CHICAGO
THREE ILLINOIS
CENTER
BLUE CROSS BLUE SHIELD
BUILDING
Aqua creates a strong identity through its architecture and has become a
landmark addition to the Chicago skyline.

serve a variety of users and residents.
•Canopied walkways lead visitors to the building’s main entrance while two
grand public stairs bring pedestrians from Upper Columbus Drive down to a
park at grade level, providing access to Chicago’s downtown area and
lakefront.
•The tower also connects to Chicago’s extensive underground pedway
system, linking users and residents to restaurants, retail, cultural activities
and jobs in the Loop and on the Magnificent Mile.
•Additional consideration was made when designing the tower’s garage exits
below grade to minimize congestion at pedestrian levels.
•To further reduce traffic and confusion, the garage’s three levels have
different access points that correlate to the tower’s specific uses and users.

ROOF GARDEN

87-story, 868-foot-tall building
designed to look like the wind is
blowing waves across its surface —
each floor sporting graceful, thin
curved balconies that look like fins
between the floors. An architectural
achievement, perhaps, but definitely
an engineering challenge.
• Magnusson Klemencic Associates
was chosen to turn architect Jeanne
Gang’s vision of “a vertically
deployed landscape” into reality.
Ultimately, the challenge required
several major engineering
innovations, starting with a custom
floor plate design to create the
unusual wave-like facade.
• Aqua has 78 individually curving
floor plates with cantilevered
balconies that extend up to 12 feet,
both for looks and to capture the best
views.
• The balconies are cast
monolithically with the floor slabs.
• The 9-inch-thick balcony slabs thin
out as they extend from the cladding
line to the edge of the cantilever.
This profile helps in drainage and
keeps rainwater off the face of the
building.
• Dozens of computer models were
created to analyze the strength and
deflection of these unique floor slabs
and their 8 miles of continuously
varying edges.
• In a wind analysis, Aqua’s balcony
design actually seemed to “confuse”
the wind, reducing forces rather than
creating additional pressures or
suction.

WALLS
81-82ND STOREY
BELT WALLS
57TH STOREY
MKA also needed to
develop a new structural
system to enable the
construction of the
building.
The new system
combined a concrete
core, stepped concrete
shear walls, outrigger
walls at levels 55 to 58
and 81 to 82, belt walls
at level 57, and
building columns, all
on top of 31 drilled
rock caissons(diameters
ranging from 4 to 10
feet and extending up to
112 feet below grade
and six feet into a layer
of dolomite).
The core and shear
walls incorporate four
different concrete
strengths to optimize
performance and
consolidate strength
while the strategically
located outriggers and
belt walls broaden the
stance of the building
and engage the
building’s exterior
columns to resist sway.

12
FEET
SAME FLOOR PLAN ON EACH STOREY
UNDULATING BALCONIES :
EACH INDIVIDUAL TO THE STOREY