Walter Martinelli is an architect educated at the Politecnico di Milano, Italy. He ran his own office from 1987 to 1992 in Bergamo, Italy, working on residential, cultural and educational projects. He then moved to New York and was involved in a broad range of project types including townhouse renovations, restaurants design with Tihany Design, corporate interiors with Ted Moudis Associates, an institutional project and new residential and historic restoration projects with Zivkovic Connolly Architects.

In 1995, working on his own, Walter Martinelli renovated a Victorian house in Maine for Judith Sulzberger of the New York Times and, in 1996, was involved, as principal architect, in the design of public buildings and urban planning in the north of Italy.

In 2004, Mr. Martinelli opened his own office, working on several projects. These include a Soho loft renovation at 484 Broome Street and two new 4,500 square feet loft interiors at 219 East 67 Street, in New York City, completed between 2007 and 2008. Between 2008 and 2009, Walter Martinelli worked on residential projects in Brooklyn and on a preliminary design of the new Brooklyn Waldorf School. In 2009, he was selected to submit a design for a resort in Bryce Canyon, Utah and received second place.

Walter Martinelli has participated in several urban design competitions. In 1988, he received a special mention for the design of a leisure and educational building in Ranica, Italy, and in 1989, a second prize for a public library in Bergamo, Italy. In 1996, he received the fourth prize for a memorial in an international competition in Minamata, Japan. 

Mr. Martinelli has also designed furniture and lighting and has been part of the faculty at Pratt Institute in Brooklyn, New York during the 1990 and 1991 International Design Summer Seminars of Architecture and Urbanism.