Again comprising two skins of steel (or aluminium) but with rigid polyurethane insulation factory bonded to the steel faces eliminating the possibility of cold spots and interstitial condensation.

With its high performance, versatility, and speed of installation, the composite panel is widely regarded as a superior product to the built up system, but at a slightly increased cost.

Composite panel manufacturers are however quick to point out that the small premium paid at construction phase is soon recouped due to improved thermal efficiency.