This document describes the infrared method for measuring the thermal resistance and thermal transmittance of opaque building elements on existing buildings when observing high emissivity diffuse surface using an infrared (IR) camera. This document demonstrates a screening test by quantitative evaluation to identify the thermal performance defect area of building elements.

This document aims to measure the thermal transmittance (U-value) of a frame structure dwelling with light thermal mass, typically with a daily thermal capacity calculated according to ISO 13786 below 30 kJ/(m²K).