In 1993 Marco and his twin Gianluigi founded the Studio Associato Architetti Giammetta.

Since 2014 they have been carrying out their professional activity through the integrated design company Giammetta Architects Srl. They have been invited to present their work in important universities and in various Architecture Conferences. They also participated as guests in various television broadcasts on thematic channels (SKY, Alice, Interni di Autore, Working in Progress). Their works have been published in the most important international architecture magazines and books such as:
DOMUS, INTERNI, ABITARE, OCTAGONO, IGLOO, NOVUM, AD, MOTTA Editore, Link International, the ARCHIVOLT, etc. They have carried out important interior design projects on the themes of Catering, Night Clubs, Wellness Centers, Hotels, Offices, Sports Centers and Congress Centers, and have developed various "format" projects of shops for the most important franchising networks, such as Enel si, Tim, Wind, KiPoint, Telecom, Peroni, Comifar, Boccadamo. They have participated in numerous National and International Architecture Competitions and are currently working on the construction of several buildings, such as a production studio in Budapest (Hungary), the expansion of a deconsecrated Church converted to a Multifunctional Space in Viterbo (Italy), a Sports in Rome (Italy), the construction of a Commercial Building in Rome (Italy) and a Winery in Costanza (Romania). Since 1994, in parallel with the architectural design activity, they have taken care of the Ideation and Artistic Direction of Conventions and Special Events aimed at the launch of new products and the incentive of the sales network and Institutional Stands, for clients such as: AMC, SAGIT, ALGIDA, ELDORADO, CONFESERCENTI, MOBILOIL, CONFAGRICOLTURA, CONFCOMMERCIO, MERIDIANA, STREAM, ACI, VIASAT, EXPERIAN, IRIDIUM, MERCEDES, PROCTER&GAMBLE, AIR ONE, WIND, BERETTA, AIS, ERICCSON, QUAM-IPSE, TELECOM, ENEL SI, ANAS, POSTE ITALIANE, PERONI, APRILIA, CAPITALIA.