Condos Rise On Glove-Tight Site
Hunzinger Construction Co., Brookfield, Wis., is the general contractor constructing the Park Lafayette Condominiums now going up at the corner of Lafayette and Prospect streets on Milwaukee's east side.
Renaissant Development Group, Oak Brook, Ill., owns the building, which will house 280 luxury condominiums and townhouses. In addition to its twin 20-story towers of one-, two- and three-bedroom condos, the building will offer residents a landscaped sun deck on the third floor, four stories of secure underground parking, two fitness centers, two business centers, and two entertainment rooms.
Construction began in February 2007, and topping-out is scheduled for late December. The first 10 floors will be ready for occupancy in September 2008, with the remaining 10 stories scheduled to open in January 2009.
Hunzinger Construction Co. is a family-owned and -operated construction business whose history stretches back a hundred years. Its current management is the third generation of the family to run the company, which offers a full range of construction services, from consulting to general contracting, construction management and design-build.
Listed continuously since 1980 as one of the Engineering News-Record (ENR) top 400 U.S. construction firms, Hunzinger has also made ENR's top 100 construction-management firms and top 100 design-build companies. It is a member of the U.S. Green Building Council and was recognized as one of the three safest contractors in the United States for 2007.
Consulting Leads To Constructing
Park Lafayette's developer, architect and structural engineer are all from Illinois, so as they began concepting the Park Lafayette project, they contacted Hunzinger to act as a consultant with experience in the Milwaukee construction market and municipal procedures.
Hunzinger's expertise and ability to solve problems while consulting landed it the opportunity to be general contractor for the $71-million construction project.
Site Presents Multiple Challenges
The small, triangular site at Lafayette and Prospect came with a number of challenges.
First, even though more than 50 years had passed since a gas station had operated on the site, regulations required soil testing and remediation.
Second, because the building will fill the entire 46,810-square-foot site from lot line to lot line, there will be little or no space to stage materials or place heavy equipment during most of the project.
In addition, two sides of the site are bounded by streets that cannot be closed, and the third abuts a steep, wooded downslope that drops about 30 feet to a public path. So there is also no room for staging equipment and material next to the site.
Finally, one end of the site sits 13 feet higher than the other.
Project Manager Will Wright, a construction-industry veteran with 19 years of experience, is unfazed. "Every site has its own little set of challenges." he says, "A good crew working together can excel regardless."
Digging Down Before Building Up
Hunzinger's first step in the project was excavating virtually the entire one-acre site to a depth of 50 feet in order to create space for Park Lafayette's four stories of underground parking. All of the excavating was done from within the site, using a 75,000-pound hydraulic backhoe, a 130,000-pound hydraulic backhoe and a bulldozer.
As the hole deepened, some of the excavated earth was piled and compacted into a ramp that enabled dump trucks to drive into and out of the excavation. When progress eliminated the ramp, the smaller excavator and dozer remained in the hole while the larger excavator perched at street level on one end of the site to load trucks.
Each time the excavators had dug down 5 more feet, the vertical sides of hole were reinforced with embedded rods and plates, then covered in concrete. The process built the parking structure's outside walls in successive rings as the hole deepened.
After the excavation had bottomed out at 50 feet, its floor was paved and Hunzinger began constructing the building's concrete support columns and four stories of underground parking structure.
Said Project Manager Will Wright, "This interesting project offers lots of opportunities for innovative solutions, and the crew is coming up with them. So far, things are going very well."
Towercranes Give Project A Lift
Immediately after the floor had cured, Hunzinger leased two fixed-base towercranes to work the project. One sits 371 feet tall and is rigged with 164 feet of horizontal boom. The other sits up 333 feet and has 131 feet of horizontal boom. Both are positioned so they will not significantly interfere with construction of the building's two 20-story towers.
Wright says, "Based on space, reach and capacity, these towercranes are perfect for this job. We just need to be sure we make the best possible use of their time and capabilities." The two cranes regularly handle forms, rebar and shoring; unload materials from delivery trucks; and pour concrete using 3-yard buckets. They will also handle equipment and materials for subcontractors working on the mechanical, electrical, plumbing, and fire-protection systems.
It's All About The Concrete
Park Lafayette is being constructed completely of poured concrete — 41,000 cubic yards of it. Although many of the larger pours are handled by pump truck, thousands of yards of concrete are also being placed by bucket.
Says Wright, "We use several different mixes, depending on where in the building the concrete is going and what it's doing structurally. The columns and their surrounding areas use one mix, general flooring uses another and other areas use a third. We pay very close attention to the concrete."
One efficiency-enhancing innovation Hunzinger uses on this job is the climbing, adjustable, wall-and-column forming system that the company helped design. Two of these forming systems work on the project, and they boost productivity while reducing the workload for the towercranes.
"The self-climbing adjustable forms have worked out really well," says Wright. "The form sections are mounted on rollers that travel along a frame of steel beams. That eliminates having to handle several individual panels with a crane. We just roll the forms along the frame till they're where we want them. Then we lock the forms into place and pour. After the concrete has cured, we release the forms, climb the unit to the next level and set the forms for the next pour."
Electronic Positioning System Boosts Efficiency
Hunzinger has also been seeing increased efficiency thanks to its new Trimble one-person robotic positioning system, used every day for work that ranges from checking grade points to doing layout, finding elevations, locating columns, and verifying finished work.
The system consists of an SPS700 Total Robotic Station coupled with a hand-held LM80 Layout Manager. All of the project's blueprints are stored electronically in the layout manager, so they are always available for reference.
Says Wright, "This robotic positioning system really saves time. Before, layout took two people, a tape measure, and a lot of shouting back and forth. With this system, one person does in 20 minutes what two people used to do in three hours — and does it with 1/16-inch accuracy.
"That gain in speed delivers a multiplied ripple effect on productivity," Wright said, "because a crew can't start work until the layout is done. Our one operator now lays out work for five crews."
Wright also uses the hand-held Layout Master to print detail drawings for workers to have on hand where they're working. "It helps make sure the communication is clear. It helps people keep moving with their work. And it helps make sure things are done right. That adds up to better quality and productivity," says Wright.
Heading Skyward, Right On Schedule
Surveying the job site in mid-August as the first above-ground story nears completion, Wright says that an amazing amount of work is hidden in the ground. "We've essentially dug out and built a four-story building already, but only one floor shows right now. From here on up, the progress will be more visible."
As of late August, the project is right on schedule for topping out by late December and for condo owners to start moving in next September.