Text description provided by the architects. The wooden three-story house has fireproof external walls by the reason of both the site contract and the building standard law. The whole indoor surface of fireproof external walls must be coverd with reinforced gypsum boards. Because of that, floors of both the second and third floor are connected to external walls by just bolts through the gypsum boards.
In other words, the floors are detached from external walls from the point of view of wooden framework.
The floors are made of general 120mm x 120mm sectioned lumbers arranged side by side.