Bank Tower To Give New Glow To Austin Skyline
Completion Of 33-Story High Rise Office
Building Set For November
Changing the skyline of downtown Austin could be considered
risky at any time, but doing it with a 33-story high rise
office tower in the midst of economic bad times raised more
than a few eyebrows.
However, when the $137 million Frost Bank Tower is completed
in November at Fourth Street and Congress Avenue, the Capital
City will welcome a new architectural landmark that could
also help revitalize the downtown area as the exclusive location
for office space.
The Austin office of Atlanta-based Cousins Properties Inc.
developed the concept for the unique downtown high rise and
assembled a team in 2001 that included Dallas-based Constructors
and Associates Inc. as general contractor. In addition to
building what many experts believed was an extremely risky
project given the economic climate, Cousins turned to a contractor
with no previous experience in multi-story high rises.
"I think it's safe to say that many people viewed this
as a high-risk endeavor," said Constructors president
Bob Albanese. "It was going to be the tallest building
in downtown Austin and started in the middle of an economic
Cousins had worked with Constructors in the 1990s on construction
of the Frost Bank Plaza in Austin. That relationship, along
with the contractor's continued presence in the Austin area,
allowed Constructors to put together a bid package that earned
the high-profile contract.
"To earn this project, assemble a great team and then
bring it to life makes us extremely proud," Albanese
Groundbreaking took place in November 2001 for the 1 million
sq. ft. building, which will boast an 11-story parking garage
base with room for up to 1,500 vehicles. Atop the parking
structure will be a 22-level glass and Italian limestone tower
featuring 500,000 sq. ft. of prime office space.
Construction began with demolition of several clubs, restaurants,
retail shops and a bank. Crews drilled piers - with average
diameters of 52 in. - for the footprint of the structure to
an average depth of 30 ft. In the center of the footprint
is a 6-ft.-thick concrete mat slab to anchor the square core
of the building.
"The reason for the mat slab was because we had to place
all of the electrical transformers and switch gears underground
in a vault," said Constructors senior project manager
George Allen. "We felt that since we were excavating
for that and the elevator shafts, a mat slab would be beneficial
so that we could capture some more space under the building."
Workers excavated to a depth of 28 ft. for the mat slab, which
contains about 1,500 cu. yds. of concrete. The slab was completed
in just two pours.
The square core was unique from an architectural standpoint
because most similar office buildings feature rectangular
"It definitely differs from what we typically do,"
said Brian Eason, project architect and vice president for
Dallas-based HKS Inc. "The square core has some large
spans for concrete structuring and that's a unique feature.
Normally, the spans would be placed straight through the core,
but here all the beams come off the corner at an angle. That
was a challenge as far as concrete forming was concerned,
but a feature that really sets the building apart from any
Capform Inc. of Carrollton handled all of the structure's
Compaction of the site also held some special obstacles for
work crews. Surrounding the new building are several longtime
Austin structures, some of which are more than a century old
and protected as historical buildings.
"The last thing we wanted to do was shake those old foundations
too much," Eason said. "We had some anxious moments
when the drilling rigs fired up, but everything worked out
The Frost Bank Tower features several types of concrete,
including a 10,000-psi mixture for the foundation's columns
and shear walls especially designed by Robert Hill of Dallas-based
structural engineer Brockette Davis Drake.
"Starting off with 10,000 psi was certainly something
unusual," said Constructors project superintendent Barry
McManus. "The mixture was so rich that it initially took
about three days to set. Of course, we needed that mix to
set in one day. But Robert made an adjustment from a chemical
imbalance in the initial mix and that resulted in the perfect
The entire core area is comprised of shear walls around the
elevator areas with all exterior girders tied in. Each shear
wall consists of concrete between 10,000 psi on the lowest
level to 5,000 psi on the upper floors. Interior concrete
beams average 20¾ in. by 30 in. until reaching transfer
floors where the weight of the upper tower is transferred
onto huge girders tied to the cores. Beams on the transfer
floors are as large as 80 in. wide and 40 in. deep, while
the concrete girders average 30 in. by 6 in.
Austin-based Capital Aggregates supplied the more than 62,000
cu. yds. of concrete for the project and Pumpstar of Buda
used an 8,000-psi, twin-engine diesel to get the mixtures
to the upper levels.
"We tried not to pour with the tower cranes because of
their limited use and the fact that the formwork would be
flying, so we utilized the pumping system all the way to the
top," McManus said. "On average for the total project,
we would lay about 100 cu. yds. per hour on the deck. We pumped
twice a week on the tower and three times each week on the
parking garage until topping out. We turned a floor on a tower
about every 4½ to 5 days on the tower and then every
about seven days on the parking structure."
Austin-based CTR installed 7,100 tons of reinforcing steel
for the project, and Houston-based Suncoast Post-Tension handled
the more than 400 tons of PT cable that are contained in all
beams and girders throughout the building.
Atop the Frost Bank Tower is an architectural feature that
should redefine Austin's cityscape.
A unique 99-ft. crown of structural steel and glass curtainwall
serves as the exterior focal point for the tower, capturing
and reflecting sunlight during the day and emanating a glow
throughout the nighttime sky via a high-intensity lighting
And while the tower crown will be the signature of the new
structure, there were some major obstacles to overcome to
Before beginning construction of the crown, Constructors project
manager Robert Salgo built a scale model to determine how
erection of the more than 250 steel pieces could be achieved.
The model also yielded other valuable information.
"What we discovered through creation of the model was
that certain things needed to be modified to yield a more
constructable envelope," Salgo said. "Additionally,
the purpose of the model was to establish a close working
relationship between the erector and the fabricator because
we also adjusted some of the fabrication of the pieces to
yield a more effective erection sequence."
Myrex Industries of Houston fabricated the steel for the crown
and Austin-based C. Young & Co. handled the elaborate
erection process. The pieces were hoisted to the top of the
structure by tower cranes supplied by Texas Crane of San Antonio.
The four jack frames that form the crest of the crown are
the largest pieces and weigh approximately 10,000 lbs. each.
Movement of the crown also factored into the equation. "All
high rises move to a certain degree and you just have to make
your calculations based upon that fact," Eason said.
"How the structural steel is erected, how the curtainwall
you have to make sure to include everything
in those calculations."
Once all of the structural steel pieces were erected atop
the 25,000-sq.-ft. footprint of the crown, painters applied
two coats of cream-colored paint to the steel followed by
installation of more than 40,000 sq. ft. of curtainwall by
Dallas-based Haley-Greer Inc.
An impressive array of lighting will begin on the back of
each of the crown's four sides and massive steel hip tubes
will serve as raceways. The high-intensity light will enter
at the bottom and exit through holes cut in the tubes, crisscrossing
one another to leave the top of the building with a dramatic
glow at night.
Impressive Top To Bottom
People entering the building on ground level will be treated
to an impressive display of architectural features inside
A variety of retail space and outdoor seating areas will be
available in the more than 5,000 sq. ft. of plaza space opening
onto Fourth and Congress. A unique glass water feature will
also greet visitors as they make their way toward the lobby.
The lobby floor features a unique Indian blanket pattern with
an intricate design of stars melding into one another. There
are four different colors in the lobby floor - gold, beige,
cream and black - utilizing a combination of marbles and granites
imported from Spain, France and Italy. The 5,000-sq.-ft. lobby
area will also boast other unusual features such as imported
eucalyptus wood wall treatments, courtesy of Durham, N.C.-based
project design architect Duda/Paine Architects.
A combination of EFIS material, Texas white limestone-colored
precast panels, Italian white limestone and nearly 240,000
sq. ft. of glass curtainwall will comprise the exterior. The
curtainwall will feature vision glass as well as fritted glass,
which is manufactured from particles of glass that are fused,
or sintered, into a solid but porous body that can be sealed
into glass tubing for an entirely glass filter.
As of mid-June, approximately 50 percent of the building's
office space had been leased. The first tenants are expected
to begin inhabiting the structure by early next year.
||Cousins Properties Texas LP, Austin
||Constructors & Associates Inc.,
||HKS Inc., Dallas
||Duda/Paine Architects LLP, Durham,
||Michael E. James & Associates,
||Brockette Davis Drake, Dallas
||Turner Collie & Braden Inc.,
||Bludau Fabrication, Halletsville
||Myrex Industries, Houston
||Hughes Detailing, Houston
||Elite Masonry Inc., Converse
||Haley-Greer Inc., Dallas
||Texas Fifth Wall Roofing
Systems Inc., Austin