HOME ABOUT US DESIGN PROCESS FEATURED PROJECTS
   FEATURED PROJECT            
“If you want it done right, get Kehl Associates” Director of Construction & Quality Assurance University of Notre Dame ©2025 Kehl Associates LLC- All Rights Reserved 3010 Lyndon B. Johnson Freeway Suite 1200 - Element Towers West Dallas, TX 75234 888-881-5345 7900 International Drive Suite 300 - International Plaza Minneapolis, MN 55425 612-332-5345 Kehl Associates, LLC Minneapolis • Denver • Dallas • Phoenix In 2025, as we celebrate our 40th year, we are thankful for the many high-profile projects we have been part of, including a dozen projects for the University of Notre Dame, multiple projects for the Univ. of MN and the Univ. of WI, projects for Palace Theater, Dow Chemical, Gander Mountain, the MN State Senate, and countless theaters, churches, schools, arenas, auditoriums, zoos, and more. My personal thanks to our clients and friends who have made our work so successful and enjoyable. I look forward to serving you for years to come. Robert Kehl Founder/Principal email Robert Kehl
Kehl Acoustical Modeling Serves as Successful Alternative to Lab Testing Permasteelisa Commissions Kehl Associates to Model Curtainwall Too Large for Riverbank Labs Test Chamber
The award-winning 54-story office tower at 150 N. Riverside occupies a two-acre site in the heart of downtown Chicago.  Wedged between the Chicago River and active Amtrak rail lines, the land sat vacant for decades.  It was considered an unbuildable site due to the constrictive features of the location.  Through the use of cutting-edge structural engineering by Magnusson Klemencic Associates of Seattle, coupled with state-of-the-art architectural design by Goettsch Partners of Chicago, and a world-class construction team, headed by Clark Construction of Chicago, the developer, Riverside Investment & Development, succeeded in building an iconic class-A office tower directly on the riverfront, in conjunction with a surrounding public park/green space and riverwalk. Intended for LEED Gold Certification, care was taken in every aspect of the design to ensure that the LEED goals were met, including the acoustical goals for outdoor-to-indoor noise control.  Design and construction of the architectural envelope, a key part of successful noise control, was contracted to Permasteelisa Group, a leading global specialty contractor that provides design and fabrication of custom architectural envelopes for hi-rise buildings around the world.  For this project, their scope of work included nearly 500,000 square feet of custom floor-to-ceiling unitized curtainwall.  Permasteelisa sent a sample of each  curtainwall assembly to Riverbank Labs for acoustical testing prior to fabrication, to ensure that the custom curtainwall met the acoustical specifications.   
Two of the largest curtainwall assemblies for this massive building, however, were too large to be acoustically tested in Riverbank Lab’s NVLAP Certified test chambers.  Permasteelisa turned to Kehl Associates, an early adopter of computer-aided acoustic modeling, to verify the acoustical properties of the oversized curtainwalls.  Kehl Associates first modeled the standard size curtainwalls, using Riverbank lab’s test results for those units to calibrate their acoustical model.  The oversized units were then modeled with the calibarated model and the acoustical specifications were verified.  Kehl associates confirmed that the oversized curtainwalls met the acoustical specifications and the curtainwalls took their place in the creation of this successful building project.  The riverfront office tower at 150 N. Riverside garnered over 28 design awards and is now a permanent icon on the Chicago skyline and a testament to creativity and modern engineering.
NOISE ISOLATION is one of the specialty design services offered by Kehl Associates.  We provide acoustical design services for all types of facilities.   
HOME