The use of Life Cycle Assessment (LCA) for materials/product design is increasing in relevance at the European building industry level. The possibility to investigate the environmental burden of materials and products for building construction, either for civil or industrial use, is a practice that can help the designer in the selection of solutions able to provide lower environmental impacts during construction and the use phase. Taking into account the wide availability of different materials, their selection in the case of buildings is a particularly difficult performance issue because a single building results from the combination of many possibilities. First of all the designer has to select functions that can be realised with the use of different materials and this constitutes the basis for the application of the LCA methodology, with particular regard to the comparison and simulation stage. The passage from a subjective choice of ecological materials, based on the perception of natural characteristics, to an objective identification and absolute measure of environmental burden, linked to the specific material production in a life-cycle perspective, constitutes the main feature of the revised bio-architectural approach that foresees sustainability as a key element for a successful project. This paper reports the application of eco-design methodology to an Eco-Industrial Park (EIP) situated in a rural area in the North-West of Italy which has been financed by the European Commission.