Heat transfer through conductive materials that bypass insulation, reducing energy efficiency and potentially causing condensation problems in buildings.

Thermal bridging is heat transfer through conductive materials that bypass insulation, reducing energy efficiency and potentially causing condensation problems in buildings by creating paths of least thermal resistance through the building envelope. This significant energy performance issue occurs when thermally conductive materials such as steel, aluminum, or concrete create continuous paths that allow heat to flow directly from interior to exterior spaces, effectively short-circuiting the insulation system and creating localized areas of heat loss or gain. Thermal bridging is a critical concern in energy-efficient construction where it can dramatically reduce the overall thermal performance of building assemblies, increase heating and cooling costs, create comfort problems for occupants, and lead to moisture-related issues including condensation and mold growth, making it essential to identify and address thermal bridges in high-performance building design and construction.

Thermal bridging occurs in various building locations and assemblies including structural connections where steel or concrete beams, columns, and connections penetrate the insulation layer, window and door installations where conductive frames and fasteners create thermal paths through the building envelope, balcony and canopy attachments where structural elements extend through insulated wall assemblies, foundation connections where concrete footings and slabs create thermal paths to the ground, roof assemblies where structural members and penetrations interrupt insulation continuity, and mechanical system penetrations where pipes, ducts, and electrical conduits create thermal paths through insulated assemblies. Each thermal bridge location requires specific strategies and details to minimize heat transfer while maintaining structural integrity and functionality.

The types and characteristics of thermal bridging include linear thermal bridges that occur along continuous elements such as structural members, window frames, and building edges, point thermal bridges that occur at discrete locations such as fasteners, anchors, and small penetrations, geometric thermal bridges that result from building shape and corner details that increase surface area and heat transfer, material thermal bridges that occur when high-conductivity materials are used in otherwise insulated assemblies, and installation thermal bridges that result from gaps, compression, or discontinuities in insulation systems. Understanding thermal bridge types enables targeted mitigation strategies and improved building performance.

Fun Fact: The term “thermal bridge” was first used in building science in the 1970s during the energy crisis, and modern thermal bridging analysis techniques were developed alongside computer modeling in the 1980s and 1990s.

• Bridging
• Bridging Clip
• Thermal Barrier