A showplace
Design-build helps contractor handle unexpected design changes

By Sam Barnes

A new $9 million, two-building Lexus of New Orleans dealership is a showroom for the advantages of the design-build project delivery method.

Ron Babin, vice president of design with Woodward Design Group, said alterations to the design after groundbreaking could have forced the schedule into a tailspin had it been a traditional design-bid-build project.

"Having full control of both the design and construction helped us react quickly to changes and more readily manipulate the schedule to achieve deadline," Babin added.

Owned by design-build contractor Carl E. Woodward of New Orleans, Woodward Design became involved in the project in January and designs were still incomplete when the construction crew broke ground a month later.

Ultimately, the design-build team will construct a 50,000-sq.-ft., two-story service bay and parking garage and 26,000-sq.-ft., two-story showroom to replace the dealership's existing complex.

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"When construction began in February 2003, we demolished a structural steel and metal service bay and an existing concrete block showroom that were in the path of the new service bay," said Carl E. Woodward project manager Gordon Jobe. Rabalais Excavating performed the demolition.

The first design change came early when Gulf South Piling & Construction of Metairie ran into some unexpected underground foundations while driving composite piles for the service bay and parking garage. Designers chose to re-route the pile locations when they could not punch through.

By conclusion of the pile driving in May, Gulf South had driven 688 12-in.-diameter, 70-ft.-long composite piles for the service bay building, made of 55 ft. of timber and 15 ft. of metal can. The showroom will get an additional 250 piles later in the project.

Engineers developed pile length estimates by studying foundations from existing nearby structures and soil borings by Gore Engineering of New Orleans.

"The lengthy piles were necessary to reach firm material," Jobe said. "We were expecting an 80-ft.-long pile in the beginning, but were able to shorten it a bit." Crews poured pile caps and grade beams after pile construction.

An owner request that some of the entrance dimensions be altered prompted the contractor to manipulate the schedule once the foundation was in place.

"We'd originally planned to pour the slab after the walls were up, but the design change forced us to start the slab early. If we hadn't we would have had three weeks of down time," Jobe said. "By the time we began precast erection in July, the first floor slab was already halfway poured." The 6-in.-thick slab is reinforced with steel.

Tindall Corp. of Biloxi, Miss., is supplying and installing more than 240 12-in.-sq. precast columns, spandrel panels and wall panels for the service bay.

"They're erecting columns and panels right now," Jobe said. "They'll work down the west side of the building and continue clockwise around the building."

Since there is no room to stockpile the precast at the site, Tindall must deliver about 15 pieces a day on five trucks from its Biloxi casting yard two hours away.

"All of the precast has been finished and cured, so it has become just a matter of getting it to the site as we need it," Jobe added. Although Carl E. Woodward personnel have observed the casting operation, Tindall performs its own testing to ensure that specifications are met.

"Once the precast is in place, the 8-in.-thick walls will be painted for aesthetics," Jobe said.

The second floor decking and roof will be topped with a 2-in.-thick topping slab reinforced with wire mesh. Concrete is being supplied by Lafarge Concrete and pumped by Cajun Concrete Services, both of New Orleans.

Jobe said the service bay structure will be built strong enough to support a third floor that will serve as a second garage level. There are no immediate plans, however, to build the third floor.

"The topping slab on the roof gets a waterproof membrane and will be structurally ready to serve as a third floor when necessary," Jobe said. "We also incorporated anchor bolts into the roof to support additional precast."

Inside the building, a steel mezzanine will be constructed for parts storage.

"The service bays will have a durable floor surface and an underground exhaust recovery system that will send exhaust to a fan," he added. Yet another delay occurred when the owners decided to add an oil change pit to the back of the building, pushing the project back by two months.

Upon completion of the service bay in October, the Carl E. Woodward crew will begin constructing the new showroom, which is made of structural steel supplied and erected by Cowboy Steel Co. of Baton Rouge.

"Much of the showroom exterior will be glass and glazing, with some stucco," Babin said.

An entrance tower will be the most noticeable exterior element, reaching 33 ft. tall and measuring 28 ft. wide by 18 ft. deep. The structural steel-framed tower will require about 3,000 sq. ft. of granite or tile cladding.

"Also impressive is the 4,000-sq.-ft. showroom on the first floor," Babin added. The second floor will support offices, a workout room, showers and a lunchroom for employees.

Drywall will be used for most of the interior partitions in both buildings.

"After we finish the new showroom, we'll demolish the existing showroom and pave the site," Jobe said. "The project should be completed in the summer of 2005."

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For more design-build project information, go to: http://www.dbia.org/