Established in 1984, 3rdLine.Studio has provided services across Northern Ontario for over 30 years.

Founding partners Dennis Castellan and Peter Dewit first opened a small studio with a staff of four in 1984. The office grew rapidly in the following years with the completion of several noteworthy projects including the masterplan, library and Valley East Recreation Centre, the New Sudbury Public Library, Sudbury Airport, and a number of projects in the downtown core such as the renovation of the Service Canada Centre and the Wellness Centre / YMCA + Older Adult Centre.

During this time that Tim James, Mike Ladyk and Professional Quantity Surveyor Sergio Cacciotti became partners. In the years since, the office has grown attracting and completing various types of work across northern Ontario and beyond.

Today, the studio has a staff of 20 that brings together a diverse team of Architects, Intern Architects, Technologists, Professional Quantity Surveyors, Professional Project Managers, and Contract Administrators.