Eco-design aims at improving the production process of a single product and eco-design practitioners often consider environmental performances of a product as a part of its initial functionalities. Only the use of LCA can quantify environmental performances. Because of its comparative nature, using LCA for eco-design requires comparing a new solution to an existing one. In the construction sector, materials are often considered as an eco-design variant. The use of a construction material is undeniably linked to its intrinsic properties but the link between these properties and its functions is not always obvious because several physical scales are nested (materials, in construction elements, in constructed objects). Using LCA in that frame means to compare various materials on the basis of identical fulfilled functions. The purpose of this article is to suggest a generic approach for using LCA to eco-design materials for construction. This approach takes into account the multi-functionality of materials, the "nested scales" of products, and the lack of knowledge at the early stages of design. The proposed approach might be the most convenient accompanying approach that should occur all along the design process from the material to the constructed object.