Glossary · Testing & air leaks

Thermal bridging

Also called: thermal bridge · thermal bridges · cold bridge · cold bridging · thermal break

Heat taking a shortcut through materials that insulate poorly, like wood studs, steel or concrete, running from the warm side to the cold side.

What it means

Insulation fills the spaces between studs and joists, but the framing itself conducts heat much faster, creating lines of heat loss you can often see on an infrared (thermal) image. Concrete balconies, steel beams and the webs of concrete blocks act the same way. Continuous insulation over the framing, or a thermal break, interrupts the bridge.

Why it matters in an audit

Thermal bridges make a wall perform worse than the R-value on the insulation label suggests, and the cold spots they create can collect condensation and mould.

Typical numbers

Reference values with their sources. Your energy advisor’s report gives the figure for your own house.

What	Value	Source
Share of a typical wood-frame wall that is framing	Nearly one-quarter of the wall area	bsesc.energy.gov ↗
Walls' share of house heat loss (NRCan)	About 20%	natural-resources.canada.ca ↗

Sources

Learn more here

Related terms

Continuous insulation (ci) A layer of insulation running unbroken over the framing, usually rigid boards on the outside of walls, to stop heat escaping through studs.
R-value How well a material resists heat flow; higher is better, and insulation is rated with it, such as R-20 for walls or R-50 for attics.
Infrared (thermal) imaging Using a heat-sensing camera to show warm and cold spots on walls and ceilings, revealing missing insulation and air leaks.
Condensation Water that forms when humid air touches a surface colder than its dew point, on windows, cold pipes or hidden inside walls and attics.
Rigid foam (EPS, XPS, polyiso) Stiff insulation boards made of foam plastic, used on foundations, under slabs and as a continuous layer over walls and roofs.

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