After graduating in 1967 from the Polytechnic of Milan, Nicolin began his professional architectural design career, parallel to teaching and researching in the field of architecture. With others, he won the international competition for the new seat of the University of Calabria (1972). He is a founding member of Gregotti Associati. He is full professor of Architectural Composition at the Faculty of Architecture at the Polytechnic of Milan.

Since 1978, he has pursued his professional work at Studio Nicolin in Milan.

His architectural and urban designs include Belice1980, IBA in Berlin in the early ’80s, Nine parks for Milan (1995), and the Oslo Biennial 2000. In addition, he has worked extensively in communications and exhibitions, including in the The Laboratory of Belice (1982), Reconstruction of the city (1985) and the XVII Triennale with the exhibition Imagined Cities: Nine designs for nine cities (1987) and, also at the Triennale, The cities of the world and the future of the metropolis (1988).

His interest in urban design is evidenced in his proposal for Oslo (2000), his proposal for Garibaldi Repubblica area of Milan (1992-2004) and the historic quadrangle of the Fiera di Milano (2004). His career as an architect is also linked with the design of new cultural and meeting spaces, including a design for the Center for Contemporary Arts in Rome (1999), the EUR Convention Center (1998), FMC Convention Center in Milan (2002), and the Provincial Center of the Province of Milan (2004).

Nicolin is also well known for his active work in journalism and publishing, through the magazine Lotus International (since 1978), which earned him the Gold Medal for Italian architecture at the Triennale di Milano (2003). He recently curated the exhibition Contemporary Architecture in Italy: Conflicts (Salerno 2005-2006). He won the Competition for the new Courthouse Center in Trento – Italy (2006), the Competition for the ‘MOdAM – Museum and School of Fashion’ in Milan (2006) and the ‘La porta di Milano’ Competition at the Milan Malpensa airport (2010). He is currently working on the Renovation of Pavilion 6 at Fiera Milano City.

Since 2009, he has been President of the Commission for Landscape of the Municipality of Milan