The services offered by Tetra Engineering have been evolving over the years. During the first years from start-up, most services concerned the design of technological systems for construction (civil, industrial, commercial, ). In this sector, Tetra Engineering was hired as a partner for the design of technological systems by high-profile international clients of the private sector such as Sephora and Mc Donald’s and by public bodies such as the Italian Ministry of Home Affairs and the Ministry of Infrastructure and Transport (see clients). Along with this sector, Tetra Engineering has also invested in researching alternative energy sources. Year by year, this sector has gained more and more importance. It used to be our R&D major interest and has now become our core business. Starting from 2006, Tetra Engineering has been collaborating in this sector with Anglo-American, Spanish, Danish and German transnational corporations. We have served both private and public clients (BP Solar, Abantia, Clear Sun International, Colexon, Soventix, etc). It can be said that Tetra Engineering provides services in the following two sectors: renewable energy and technology systems for construction.