The Equator Principles (EP) are international guidelines for project finance; they target socially and environmentally responsible projects related to large infrastructures and industrial plants, such as energy plants, oil refineries, mines, transports, and telecommunications infrastructures. The aim of this work is the set-up of a methodology for the assessment of Greenhouse Gases (GHG) emissions, that can support the decision-making process of an EPC Company when evaluating different technological alternatives, to select the best available, economically profitable, and environmentally sustainable option, in line with the application of the EP. The assessment of the GHG emissions has gained importance with the issue of latest EP’s version (Equator Principles IV, in force since 2021) that require to perform a Climate Change Risk Assessment associated to Projects. The methodology has been applied, as part of an Energy Efficiency Project, to two different units of an existing Propane Dehydrogenation (PDH) Plant built and set into operation by Tecnimont S.p.A. in the last decade: the steam boiler system and the main compressors (reactor effluent compressors). The methodology for GHG accounting has been applied both to the technical solutions currently implemented in the plant (‘base’ cases) and hypothetical ‘alternative’ technical solutions, with the final goal to assess efficiency and effectiveness of the measures that can be taken to reduce the emissions. For each ‘base case' and its corresponding ‘alternative solution’ a cost estimate has been performed too. The results provide useful information both in terms of carbon footprint and the costs related to the application of the Equator Principles, even in Projects in which their application is not mandatory.