Winner: Other

One 09 is a 17-story, 505,880-square-foot mixed-use development transforming the Lake Monona skyline. The structure features three underground parking levels, 340 market-rate residential units, a ground-floor chop house and food hall, a rooftop pool, a golf simulator, and outdoor terraces with panoramic views of Lake Monona, Lake Mendota, and the State Capitol.

One 09 required considerable coordination. The building footprint occupied the entire site, leaving only north-side access and requiring lane closures for each concrete pour.

The project required accelerated concrete strength, with 55 elevated post-tension deck pours needing to reach 3,000-psi in under 24 hours.

To stay on schedule, a deck was poured every three days for 39 pours, requiring careful sequencing and material management. Structural performance was enhanced by installing 10,000-psi buttress walls in the parking levels to support the north exterior foundation wall.

The development included a snow-melting system for the parking ramp and exterior promenade. A total of 22,650 cubic yards of concrete were poured, and the project was finished in just over 19 months. The concrete was a high-performance 6,000-psi mix with high-range and mid-range water reducers, achieving an average 4,000 psi in 24 hours.