Dear Sir or Madam,
I have developed a procedure for simplification aware symmetry detection
in building footprints (ESRI Shapefiles). You can also use it for
symmetry aware building simplification.
Download the demo application (Win32 executable) from there:
http://www.hagenschwass.name/triangle-trial.html
Evaluate the usability of the procedure, on interest and fund I can go on
developing.
Best regards
Hagen Schwaß