A defined measure, a recognised quantification method (e.g. ASTM C680 / ISO 12241 for heat loss), before/after figures or metered verification, the CapEx/OpEx involved, and a link to a disclosed target.
From our guide: ESRS E1 in Practice — full context, charts and sources there.
Boilers, kilns, heat exchangers, valves and steam lines lose energy continuously. Inzonex makes patented (UK GB2508992.1) removable modular insulation — snap-fastened covers engineered per temperature tier, not generic off-the-shelf jackets: