Thermal Bridging Research: Transitions between Wall Systems

One of our many in-house research efforts is a large, collaborative project. We investigated the Thermal Performance of Façades through the AIA Upjohn Research Initiative.

Thermal bridging in building construction occurs when thermally conductive materials penetrate through the insulation creating areas of significantly reduced resistance to heat transfer. These thermal bridges are most often caused by structural elements that are used to transfer loads from the building envelope back to the building superstructure. Though design professionals generally understand that thermal bridging is a concern, few can quantify the extent of its impact on building performance.

Small changes in designs can still lead to dramatic improvements in performance. With careful detailing and attention to the issues of thermal bridging, the design and construction industry can improve the performance of our building envelopes.

Today we’re sharing our findings regarding transitions between wall systems.

As-built condition, curtainwall to stone veneer base

Just as thermal bridging was observed at the foundation to wall transitions, thermal bridges have been observed at the interface between wall systems when there are multiple façade systems employed. Common sources of loss were observed because of the complexity introduced due to two systems coming together and the challenge of maintaining the thermal barrier across the transition. In these interfaces, the decrease in the R-value was observed to range between 50-80%. 

Improved details were developed with the goal of limiting the complexity, aligning the insulation between systems and minimizing the amount of systems transitions were seen to improve performance.  As with most façade systems, careful attention should be paid to how systems are supported at the perimeter.

Related:
Thermal Performance of Facades: Final Report
Thermal Bridging Research: Curtain Walls
Thermal Bridging Research: Investigating Insulation Thickness for Renovations
Thermal Bridging Research: Masonry Veneer Walls
Thermal Bridging Research: Window Transitions
Thermal Bridging Research: Foundation to Wall Transitions
Thermal Bridging Research: Rainscreens
Thermal Bridging Research: Metal Panel Wall Systems
Thermal Bridging Research: Parapets