Fire regulations in buildings are in perpetual motion. The reference text on the subject in France is of course the decree of January 31, 1986; the latter was modified by the decree of August 7, 2019, which comes after a report by CSTB following the dramatic fires of the Grenfell tower in London.
The regulations thus revert, for 4th family buildings, to provisions no longer authorizing combustible materials on the facade; the materials used must justify an A2 classification (noncombustible), so even fireproof wood is excluded since it is at best B-s1, d0 with current fireproofing technologies.
For 3rd family buildings, the facade systems must either be classified at least A2-s3, for each of its constituent elements without any air gap, or demonstrate their overall effectiveness via a laboratory assessment. For the specific case of wood cladding facades, the Timber Construction and Fire Propagation Guide through facades in application of IT 249 2010 version of the CSTB offers a book of detailed solutions to comply with these provisions.
Source and full text of the decree: Legifrance
Download the CSTB Timber Construction Guide (in french) > le Guide Bois Construction du CSTB
