11. December 2017

The Spark: A First for Wisconsin

from Nate Lambrecht
The Spark Schöck STB
In progress construction at The Spark, the first building in Wisconsin to install concrete-to-concrete STBs

With any new construction technology, there are always early adopters, but only one can claim the designation of “first.”  With the construction of The Spark, American Family Insurance and the project’s design and construction teams can claim being the first in Wisconsin to incorporate concrete-to-concrete structural thermal breaks within a building assembly.

Situated on Madison’s 800 block of East Washington Ave., the 8-story Spark is billed as “dedicated to innovation, collaboration and entrepreneurship.” In keeping with the building’s environmentally sustainable design, concrete-to-concrete structural thermal breaks, which attach––yet thermally isolate––the exterior balcony slabs from the interior floor slabs, were incorporated into the design.

Thermal breaks were recommended by the structural engineer to minimize the negative impact on thermal efficiency that a traditionally constructed slab penetration through the building envelope would create. Once the architect incorporated the detailing into the design and construction documents, it was approved by the general contractor.

Incorporating this new structural connection required all involved parties to learn about its application and coordinate among one another as the project progressed from initial design to completed installation.

Isokorb PT installation
Installing Isokorb adjacent to PT tendon layout

This particular application for a structural thermal break was not as simple as one for a conventional residential balcony. In addition to designing a connection to support a 12 in. thick slab cantilevering 10 ft off the structural slab, the structural team had to design within the limitations of a post tensioned slab.

While the use of structural thermal breaks throughout North America is now growing exponentially, their use in Europe has been a construction standard for decades, evidenced by Schöck thermal break installations numbering in excess of 10 million. North America appears determined to catch-up, however, as increasingly stringent energy codes requiring continuous insulation are adopted by municipalities and states, and inclusion of structural thermal breaks as a ‘best design practice’ becomes more prevalent.

The Spark has captured the title of first concrete-to-concrete thermal break project in Wisconsin, well before the state has formalized its code requirement for continuous insulation in 2018, demonstrating that sustainability as a mission will precede it as a mandate when responsible specifiers have their way.


Visit the Schöck North America website for more information about structural thermal breaks for concrete and steel connections. Explore the full range of Isokorb® products for balcony, canopy, steel beam, exposed slab edge, parapet and rooftop connections.

Considering structural thermal breaks for an upcoming project? Have a Schöck Engineer call you to answer your specific design questions.  


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