The soil in the area is sandy, requiring massive footings. Rather than dig individual footings, DPR excavated the entire area, poured footings and plinths, then backfilled around them. Excavating a single large area meant there was no risk of the cave-ins associated with digging footings in sandy soil, and two weeks were shaved from the schedule.
That Saved Time
Designs were not complete when the two additional floors were added to the scope and rebar—which had a lead time of six weeks—is typically not ordered until drawings are farther along. Rather than push the schedule out, DPR pre-ordered the rebar, estimating quantities based on the previous floors and allowing for changes in the field to accommodate the larger ductwork required for floors five and six.
Similarly, when the addition of two floors of cast-in-place concrete would have exceeded the soil bearing capacity of the site, the design of the roof was changed to steel, which is long lead. To keep the project moving forward, a temporary rubber roof was installed so finishes could begin on the first four floors. The cost of the temporary roof—approximately $70,000—paid for itself in time saved four times over.