Thermal Bridge
A thermal bridge is a part of a building envelope where heat moves through the assembly faster than the rest of the wall, ceiling, or floor — most commonly at studs, headers, plates, fasteners, or balcony slabs that conduct heat much better than the insulation around them. Thermal bridges reduce effective R-value, drive up heating bills, and can cause condensation if a cold framing member meets warm interior air. Continuous exterior insulation is the most effective fix.