This paper presents the progress of an investigation that pretends to identify and characterize a valid method forassessing the environmental viability of building materials, focusing on the case study of compressed earth blocksused in central Mexico.Raw earth materials have been granted the status of green, clean, or sustainable. But it has not been fully explainedwhy. Generally, the argument revolves around their low or zero energy consumption, but the environmental spectrumis much broader and complex. From the logic of life cycle analysis (LCA) it is possible to identify events at each stageof a material, from raw material extraction to the end of its useful life. Based on this logic, and generally knowing theproduction processes of three masonry materials, it becomes a deductive exercise, from which possible values areprovided with positive and negative impacts, for eight interest variables, along each stage of its life cycle. compressed earth blocks;