The coupling of urban retrofitting with climate change adaptation and environmental conservation is impacting on current industrial activities such as electricity production based on fossil fuels. Therefore, new tools are required to support adaptive reuse towards the conservation of industrial facilities, in order to leave testament of their cultural and industrial heritage once their production activities cease to exist. Multi-Criteria Decision Analysis (MCDA) can help analyse complex interactions between industrial elements, society, culture and nature, providing key benefits when approaching heritage investigations. In this context, this research concerned the design of a Multi-Expert MCDA (ME-MCDA) methodology to support the selection of paramount heritage elements in power plants based on the collection and processing of the views of a panel of experts to result in consensus groups. This approach was tested using a case study in the As Pontes power plant (NW Spain), which will be dismantled in a near future. The results achieved pointed out to cooling towers, boilers, chimney and turbine hall as the fundamental elements to preserve due to their relevance across a set of technical, historical and sociocultural criteria. These outcomes proved the usefulness of the proposed approach in favouring the valorisation of industrial facilities as heritage areas protecting the social and cultural history of a territory.