Design Strategies  To apply the proposed method in the case study, five project solutions were analysed and compared with the actual design of the building. The most recent projects of multi-family social housing in Italy were analysed to identify the design solutions [28-34]. Three different structure of the building were evaluated: X-Lam, reinforced concrete frame and steel frame. A simplified method to calculate the dimension of the structures was used. The three structures were analysed with different insulations or envelope materials. Eventually, six design solutions (Case) of the building were evaluated: X-Lam and rock wall (actual case), X-Lam and wood fiber, reinforced concrete frame with cellular concrete blocks, reinforced concrete frame with rectified bricks, steel frame and drywall with rock wool and steel frame and drywall with wood fiber. In the roof of the building only the insulation was analysed. The different design solutions maintain the same thermal transmittance of the actual envelope. As mentioned above, only the design solutions were evaluated by the LCA and LCCA. Fig. 4 shows the characteristics of the six design solution evaluated.