In this report, objective number 10 of the MARBEL project is addressed by the alignment of LCA and LCC methodologies. Those are presented in pursuance of higher consistency and robustness of the study by the definition of the named “unified approach”. It establishes the general framework, aligned with ISO 14040 series, for both environmental and economic feasibility studies including two Functional Units (FUs) covering first a cradle-to-grave approach and secondly a cradle-to-gate approach.