The Obama Presidential Center, situated on 19.3 acres in Chicago’s Jackson Park, opened on June 18, 2026. Since the Victorian era, when the city’s South side played host to the 1893 World’s Fair, this neighborhood has been the site of several of Chicago’s most impressive architectural landmarks, including the nearby Kenneth C. Griffin Museum of Science and Industry. That architectural legacy continues in the 21^st century. From the Obama Presidential Center’s below-grade tunnels to its rooftop green spaces, the three buildings gracing the campus are designed with performance in mind.

Materials installed behind the 225-foot museum tower’s impressive granite façade include 130,000 square feet of Owens Corning Thermafiber® RainBarrier® continuous insulation (ci). This American-made material installed in the tower’s exterior wall assembly contributes to fire-resistance, moisture management and thermal performance in a challenging climate and code environment.

Supporting Legacy and Longevity

Presidential museums and libraries are designed to deliver carefully crafted messages about a U.S. President’s legacy, while protecting historical documents and standing the test of time. The Obama Presidential Center is home to the first all-digital library housing the 44^th president’s e-mails, social media messages and other electronic communications. The Center offers amenities that are unique among presidential museums, including a recording studio, basketball court and dozens of public art commissions.

With performance longevity in mind, the design and technical teams, including Tod Williams Billie Tielson, Heintges & Associates, WJE and Interactive Design, specified five inches of Thermafiber RainBarrier ci in the museum tower’s exterior walls. While RainBarrier is manufactured in nearby Joplin, Mo., the decision of which continuous insulation material to install was based on much more than point of origin. Thermal performance is non-negotiable, and all forms of ci can contribute various amounts of R-value. However, mineral wool features several performance attributes that set it apart from alternative products like polyisocyanurate insulations. Because Thermafiber is non-combustible, it helps ease code compliance compared to combustible insulating materials like polyisocyanurate. Moisture in the form of rain, snow and humidity is also considered when specifying continuous insulation. The permeable composition of mineral wool allows moisture – whether liquid or vapor – to avoid being trapped, allowing the wall cavity to dry out in the event that condensation or bulk water intrusion occurs within the assembly. 

When specifying for thermal performance, it is always important to evaluate how an insulation retains its thermal performance over time. Thermafiber RainBarrier continuous insulation maintains a stable R-value and does not diminish when exposed to cold temperatures. In contrast, depending in part on manufacturer blowing agents, the R-value of some polyisocyanurate insulations can decrease significantly when exposed to cold weather conditions – when thermal performance is needed most.

Considering the Building System

Every building is a system, so it is important that materials and components be considered in terms of how they contribute to the structure’s total performance. Commercial buildings are comprised of a number of assemblies that all work together, and materials should be compatible to meet or exceed performance objectives. One example is the permeable air barrier installed behind the permeable Thermafiber mineral wool in the Obama Center’s Museum Tower. The combination of materials installed in the Museum Tower’s exterior walls contributes to a non-combustible wall assembly that also helps manage moisture movement and delivers stable thermal performance.

According to Drew Clausen, Architectural Solutions Leader at Owens Corning, Thermafiber RainBarrier continuous insulation is a very straightforward solution for a legacy design. “Thermafiber checks a lot of important boxes and makes it easy to comply with code requirements such as NFPA 285, a critical test for evaluating fire spread on the exterior of a building,” he said. “The water vapor permeability of mineral wool ci can also provide advantages over rigid foil-faced polyisocyanurate insulation, which features a very low perm rating, as well as being combustible.”

Clausen also noted the attention paid to important components in the assembly that support the Museum Tower’s energy performance. For example, on some portions of the façade, the design team selected non-conductive z-girts. These high-performance girts not only help keep the mineral wool ci firmly in place but also minimize thermal bridging through the façade, optimizing effective R-value. Much of the façade features granite, which is sourced from various quarries in the U.S. In those areas, the semi-rigid nature of mineral wool ci is ideal because it can be secured snugly around the cladding anchors and tightly (and continuously) against the substrate. This also optimizes thermal performance.

Integrating Design Intent with Enduring Performance

A presidential museum is a once-in-a-lifetime project and a once-in-a-generation opportunity to demonstrate how a high-performance exterior wall assembly can support both legacy design and longevity. At the Obama Presidential Center’s Museum Tower, the integration of non-combustible, vapor-permeable continuous insulation within a thoughtfully coordinated wall assembly reflects a holistic, systems-based approach that architects and contractors increasingly rely on in complex buildings. From code compliance and fire safety to long-term thermal stability and moisture resilience, the Museum Tower’s exterior assembly underscores how insulating material selection informed by building science can merge legacy design and enduring performance.

A Conversation About Continuous Insulation in High-Performance Buildings

Continuous insulation (ci) is a de facto contributor to high-performing enclosures in varied climate zones across North America. In the following conversation, Drew Clausen, Architectural Solutions Leader, Owens Corning U.S., talks about how ci supports much more than thermal performance.

Q: What role does location play in building enclosure design, such as the Obama Presidential Center?

A: Location influences how an enclosure is designed to manage weather exposure, temperature swings, and moisture conditions. In climates like Chicago’s, enclosure systems must be designed to support thermal performance, durability, and moisture management over time.

Q: What defines a high-performing enclosure system in modern construction?

A: A high-performing enclosure system is designed to function as an integrated assembly, where materials work together to manage air, water, vapor, and heat transfer. Rather than acting as a simple exterior layer, the enclosure contributes to the building’s overall durability, energy performance and resilience.

Q: What role does continuous insulation play within an enclosure system?

A: Continuous insulation (CI) is used to help provide uninterrupted thermal performance across the building envelope. When properly specified and installed, CI can reduce thermal bridging, support energy efficiency and contribute to moisture management within wall assemblies.  

Q: Why is mineral wool insulation commonly used in enclosure applications?

A:  Mineral wool insulation is often selected for enclosure systems because of its combination of material properties. These properties include non-combustibility, which can support compliance with fire performance requirements such as NFPA 285. Vapor permeability, which allows assemblies to dry and reduces the risk of trapped moisture is another property that mineral wool brings to enclosure applications. And mineral wool’s thermal stability helps maintain consistent performance across temperature ranges

All of these characteristics make mineral wool suitable for use in applications where fire resistance, moisture management, and long-term performance are key considerations.

Q: How does insulation interact with other enclosure components?

A: Insulation is one part of a broader system that may include air barriers, water-resistive barriers, cladding, and structural supports. The performance of the enclosure depends on how these components are designed to work together. For example, vapor-permeable insulation can be paired with compatible air barrier systems to support drying potential. Attachment systems and detailing can influence thermal bridging and overall efficiency

Q: What design considerations help address thermal bridging and constructability?

A: Thermal bridging can be addressed through detailing and material choices, such as incorporating attachment systems designed to reduce heat transfer, and using insulation materials that can be fitted around penetrations and structural elements to maintain continuity. Ease of installation and material durability are constructability considerations that can also play a role in achieving long-term performance.

Q: Why is durability important in enclosure design?

A: Building enclosures are expected to perform over long service lives, often under varying environmental conditions. Durable materials and well-coordinated assemblies can help maintain consistent thermal performance, reduce maintenance needs and support long-term resilience of the structure

Q: What can architects take away when specifying enclosure systems?

A: A systems-based approach to enclosure design can help align material selection with performance goals. When evaluating insulation and enclosure components, key considerations include fire performance requirements, the strategy for moisture management, long-term thermal performance and compatibility with other enclosure elements.  

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