The High Luminosity LHC (HL-LHC, also HI-LUMI) is a project aiming to upgrade the LHC after 2026, increasing its peak luminosity by a factor five over nominal value. The project is located at the so-called Point 5, beside the existing structures of the Compact Muon Solenoid (CMS) experiment, near the village of Cessy, on French ground. The HILUMI Project consists in the construction of four new buildings on the surface and of different underground structures, listed here under: - Vertical shaft of approx. 85 m depth, internal Dia. 7 m - Cavern at the food of the vertical shaft; L x B X H = 56 x 19.3 x 17.5 m - Tunnel of approx. 300 m length, Section B x H = 8.5 x 7.9 m - 4 side tunnels, 2 of which with access to the existing LHC - Large diameter vertical cores connecting the side tunnels and the existing LHC. Further to the design activities, which include Preliminary, Tender and construction design, the contract embraces also the Site Supervision until the closing of the Defects Liability. Part of the assignment are also al the civil inner structures, such the elevator pit and stairs system in the shaft and the steel mezzanines and the concrete chamber inside the cavern. The design has been carried out on BIM platform. The design activities have started on June 2016 with the Preliminary design and will end on March 2019, with the Construction design of the surface buildings. The site works will start on April 2018. The end of the underground works is planned by middle of 2022, the one of the surface building for the end of the same year. The most delicate part of the work is represented from the excavation of the vertical shaft, which will be carried while the LHC is operating. The remnant part of the underground works will occur during the foreseen shut down period of the LHC for refurbishment and renewal works.