When covering a wide range of products

Hi Akira,This type of question is usually determined by the Product Category Rules (PCR) for the product in question. If the PCR doesn't spell out what types of product variations can be covered within a single EPD--and the North American PCR for gypsum doesn't--you have to go by how you would define a functional unit for comparison purposes.Given that different thicknesses of wallboard have different performance characteristics AND different environnmental impact profiles, I don't see what you would gain by trying to lump those into a single EPD. You would have to have multiple parallel tables for each variant; it would be much simpler to publish a separate EPD for each, I believe. The underlying LCA work could be applied to all of them, so the amount of work involved wouldn't be that different either way.I hope this helps! --Nadav