The 42-story Mansion on Peachtree, awarded the Best in Atlanta Real Estate Award in the Residential Category by the Atlanta Business Chronicle, combines a 5-star luxury hotel with high-end condominium residences in a slender eight-sided tower ranking as Atlanta’s 12th tallest building. The Mandarin Oriental Hotel includes 127 luxury rooms, a five-star "29 Spa," full service amenities including a fitness center, pool, a business center, laundry facilities, an arcaded garden, and private dining. A restaurant pavilion with sidewalk seating opens directly to Peachtree Street, screening a formal stone-paved motor court serving the hotel guests; a second entry off Stratford Road serves condominium residents. The 616,000 square-foot development includes a second restaurant, an enclosed pool, banquet facilities, a spa and fitness center overlook a terraced garden leading down to private villas.
Preconstruction for the Mansion on Peachtree started in May of 2005 and overlapped the construction start by over a year, completing in July of 2007. Construction began in March of 2006 and completed in August of 2008. The tower is comprised of cast-in-place concrete with structural steel trusses and a precast and glass skin. The development also includes a 125,000 square-foot cast-in-place parking structure which houses 219 parking spaces.
The most notable challenge on this project was the Team’s desire to begin construction well in advance of a complete, coordinated set of drawings. Holder’s Building Information Modeling (BIM) department stepped in with a solution in December of 2006. They formed a QC Coordination Team that generated working BIM models which allowed the Team to take control of the project. With these working BIM models, the project team was able to generate coordinated shop drawings that combined all design disciplines. The coordinated shop drawings were reviewed with the Design Team and necessary RFIs were generated in order to complete the upcoming phases of construction. Through this effort, the QC Coordination Team was able to identify and avoid potential conflicts and delays before they occurred in the field. BIM was also used by the entire Team to visualize value analysis options and simplify complex building components.
Another significant challenge was working safely and efficiently within a tight urban setting. Close coordination and cooperation among the Trade Contractors was necessary to plan and execute work successfully without much space on the site for storage or material lay down. The proximity of operations to the site perimeter required that Holder pay close attention to the safety of the surrounding community.
The architectural design intent of the building appearance was to convey a “wedding cake” effect meaning that the floors tier inward and the building floor plate gets smaller as the building gets higher. Due to this feature, the tower is essentially a 27 story building stacked upon a 15 story building. In order to transition structurally, the structural engineers created a transfer floor at level 15. Eighteen steel trusses were installed at the 15th floor transition, the two largest trusses weighing in at an excess of 100,000 pounds each. Because this made the trusses too large for the 22,000 pound hoisting capacity of the tower crane, Holder worked with the steel fabricator to divide and assemble the trusses in place. Planning for the installation of the trusses began 4 months prior to the steel being delivered to the site. The total completion of this floor of the building took six weeks in comparison to the five days per floor cycle that the structure had been averaging up to that point. Without diligent work by the Holder team, this feat of engineering would not have been completed so seamlessly and allowed the project to continue on schedule.