The course will explore two very different construction materials, steel and timber, which yet have some features in common: prefabricated structural elements with homogeneous mechanical characteristics, the need for connections and typical structural types consisting of frameworks in the plane and in space. After a historical overview, the course will present the main physical and mechanical characteristics of the two materials, the most common structural types and the main sizing criteria. We will then move on to the description of production, specific characteristics and fields of application. The theme of assemblages will be dealt with in depth, and finally the course will analyse the principles of protection in case of fire and earthquake and construction measures to improve durability. A part of the course will be devoted to presenting other less common building materials, such as structural glass.