Strength class assignments and durability class assignments of wood species to be used in structures are necessary to make it possible for the engineer to design safe and durable timber structures. As a result of sustainable managed forests, more tropical wood species with relative small batch size, are coming on the market. In Europe, strength class and durability class assignments are allocated to wood species, identified by their botanical name. In practice this gives problems because the trade names may not represent the botanical wood species and the representativeness of the underlying tests is unclear. The objective of this paper is to start a discussion on the classification and sampling of structural timber for strength and durability. It is proposed to make classifications based on measurable characteristics of the timber, independent from tree species.