Oooch.
I'm not an expert in this area, but do have a general understanding and interest. As I mentioned above, Dick Schmidt has performed some recent timber frame lateral load response studies. His studies are all static/stiffness related and should translate to dynamic response. I think the rub is the method Dick uses to model the simple structures that he has tested. I believe Dick has shown that analytically predicting frame response is sensitive to joint/peg stiffness representation. I suspect that using Dick's modeling techniques would be difficult and expensive for larger more complicated frames. Dick, are you out there? I also believe there are some papers available through the Timber Frame Business Council regarding timber frame lateral load design.
Providing the information that the above NY building official is requesting might rule out having 'full' code compliant timber frames. I have seen 200-year-old frames that are extremely lightly braced that have withstood the test of time. Many times we have extreme difficulty showing a more heavily braced frame adequate for lateral loads using modern engineering to the latest codes. The above discussion tells me for certain buildings; it may potentially be impossible.
