What is thermal bridging, and which of the following is an example?

• A. A path of higher heat flow through a less insulated element; example: wood studs in a framed wall penetrating insulation.
• B. A barrier that stops heat transfer.
• C. A high-density insulation layer.
• D. A radiant barrier in the attic.

Answer: (A)

Thermal bridging happens when a part of the building envelope has higher thermal conductivity than the surrounding insulation, creating a shortcut for heat to flow through the assembly. In a typical wood-framed wall, the insulation fills the cavities between studs, but the wooden studs themselves are much more conductive. Heat moves more easily through these studs than through the insulated gaps, so heat transfer bypasses much of the insulation. This lowers the wall’s effective resistance and leads to greater heat loss or gain and potential cold spots on interior surfaces. That’s why a path of higher heat flow through a less insulated element—like wood studs penetrating insulation—is the classic example of thermal bridging. The other options describe barriers or insulation layers that don’t create that conductive pathway through the structure.