• HERBERT RAINE
  
• FRANCIS MAWSON RATTENBURY
  
• KENNETH GUSCOTTE REA
  
• JAMES R. RHIND
  
• ROSS AND MACDONALD
  
• ROSS AND MACFARLANE
  
• ROSS, FISH, DUSCHENES AND BARRETT
  
• VINCENT ROTHER ARCHITECTS
  
• RYERSON POLYTECHNIC UNIVERSITY