The Sonnentag

Posted By: David Delfosse ACEC WI News, Advocacy,

2025 Engineering Excellence Best of State

Entering Firm: Ayres Associates Inc.
Client: Eau Claire Community Complex

A Uniquely Complicated Facility

Ayres overcame significant challenges in delivering the Sonnentag, a groundbreaking 225,900-square-foot facility for the University of Wisconsin–Eau Claire (UWEC) and the surrounding community. The team collaborated extensively with UWEC and local stakeholders, balancing diverse interests to achieve a unified vision. The resulting facility includes an event center for up to 5,000 attendees, a 100-yard turfed indoor practice area and a two-story fitness center.

Sustainability Above All Else

A hallmark of the project is its zero-net-energy status, achieved through innovative partnerships and advanced engineering. Ayres facilitated the construction of a nearby solar facility and integrated a 190-well geothermal system beneath the parking lot, ensuring the all-electric building meets its energy needs entirely from renewable sources.

Meticulous material selection further underscored the project's commitment to sustainability. High-efficiency insulation, windows and control systems resulted in a complex 24% more energy efficient than similar facilities. Additionally, the team reduced the building’s embodied carbon footprint by 11.3%, reflecting a significant contribution to lowering its global warming potential.

Awards judge Tom Buchholz said, “The Sonnetag Project is worthy of award recognition. Ayres design provided renewable resources that will supply all the energy that the all-electric facility requires. Ayres delivered the Sonnetag Project on time and under budget and provided a facility for UWEC that will be a showcase in low-carbon footprint design for all to try to match.”

Setting A High Standard

The Sonnentag is not only environmentally responsible but also educational. An interactive sustainability dashboard in the lobby displays real-time energy data and highlights eco-friendly design elements. Recognized with LEED Gold v4 certification and a WELL Health-Safety Rating, the facility exemplifies engineering excellence in sustainable design.

Completed on time and under budget, The Sonnentag redefines expectations for Division III institutions, providing a top-tier event venue while setting a new regional standard for sustainable construction.

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