Following is a reply from the New York State Department of State regarding Seismic Parameters for Timber Frame Construction:

Dear Mr. Hoppe:
This is in response to your recent e-mail with questions regarding
timber frame construction.

Q1: What values should be used for braced timber-frame construction?

The Code Sec. 1617.6 states " 1617.6 Seismic-force-resisting systems.
..... For seismic-force-resisting systems not listed in Table 1617.6,
analytical and test data shall be submitted that establish the dynamic
characteristics and demonstrate the lateral-force resistance and energy
dissipation capacity to be equivalent to the structural systems listed
in Table 1617.6 for equivalent response modification coefficient, R,
system overstrength coefficient, W0, and deflection amplification
factor, Cd, values.EXCEPTION: Structures assigned to Seismic Design
Category A."
As stated above the analytical and test data shall be submitted for the
contemplated structural system.

Q2: What values should be used for a structural system using steel and
timber in the same frame?

This question may be interpreted in a number of ways:

1) The structural frame is composed of two materials, steel and timber,
in which case the answer to the previous question would apply -
analytical and test data shall be submitted.

2) The proposed arrangement meets the code definition of dual system
which would be a combination of moment-resisting steel frame and braced
timber frame. The code section quoted below would apply.
"1617.6.1 Dual systems. For a dual system, the moment frame shall be
capable of resisting at least 25 percent of the design forces. The
total seismic force resistance is to be provided by the combination of
the moment frame and the shear walls or braced frames in proportion to
their stiffness."
The design parameters for timber frame would need to be established
based on submitted analytical and test data. The parameters for steel
frame would be from Table 1617.6.

3) Steel frame (other than moment-resisting) and timber frame are used
in combination along the same axis or in two orthogonal directions. The
Code sections "1617.6.2 Combination along the same axis." and
"1617.6.3 Combinations of framing systems." would apply.
Again, design parameters for timber frame would need to be established
based on submitted analytical and test data. The parameters for steel
frame would be from Table 1617.6.

If you have any questions regarding the above please do not hesitate to
contact me at (518) 474-4073.

Sincerely,
Lucjan J. Mitas, P.E.
Sr Bldg Structural Engineer
Division of Code Enforcenment and Administration

Does anyone know of any testing that has been done to establish these parameters?
Thank You,
Chris Hoppe, P.E.