This study takes place within the framework of an ambitious restoration project of the two Japanese lodges situated at Boulogne-Billancourt, in France. The philanthropist banker Albert Kahn builds a set of gardens during the 19th century with a Japanese "village". Manhandled by the time, restorations were decided with, in parallel, an exhaustive archaeological investigation of these buildings. The AKAHN project: "Albert Kahn: archaeology of a Japanese Heritage" began in 2015. Exploratory analysis were made to direct a part of the work and in particular to find the original colors. The measurements were realized according to non-destructive methods and techniques mainly in situ. The present results are not complete and are in the continuation especially for the wood. They concern the dendrometrical studies on both houses and the characterization of their polychromies. They also participate in the implementation of a database on Asian woods in France: in the 19th century in Europe, during the period named “Japanism”, numerous buildings seem to contain same kind of woods.