Using Game Engines for Architectural Walkthroughs

• A Critique of Virtual Reality in the Architectural Design Process, Dace Campbell and Maxwell Wells, 1994

Based on the Unreal engine:

• VRND Notre Dame Cathedral ( http://www.vrndproject.com/ appears to be offline as of Sept. 2004)
• Unrealty Real-Time 3D Design and Presentation Software
  • Application of a 3D Game Engine to Enhance the Design, Visualization and Presentation of Commercial Real Estate
• Virtual GRAZ

Based on the Quake II engine:

• http://news.bbc.co.uk/hi/english/education/newsid_982000/982346.stm
  A Cambridge university development.
  Slashdot story on it:

Contains an interesting debate on 3D vs. 2D in architectural design.
Follow the above link and search for "Trevor".