Architected materials (AM) constitute a new and emerging class of materials. They are periodic lattice structures, whose macroscopic mechanical properties mainly stem from their periodic geometric configuration rather than their constituent material. AM can be obtained through the aid of 3D printing, and the combination of a wide variety of unit cells, member-level cross section features, and bulk material properties creates a nearly unbounded design space, allowing for the development of exceptional mechanical properties which would be unattainable by the constituent material alone. Among others, these properties include extremely high specific stiffness and strength and excellent energy dissipation mechanisms, while their utmost advantage is that they are ultra-lightweight structures. The applicability of AM for structural engineering applications is a new and already promising subject of research, and this project focuses both numerically (finite element approach) and experimentally (scaled-size tests) on the performance of novel slabs which are designed based on AM. The foremost advantage of architected slabs is the drastic reduction of the total building mass compared to the traditional building design with concrete slabs, which results in the significant decrease of forces introduced to the components of the structural system when mass is of primary concern, for example due to earthquake loading. Since the topology of the AM is highly tunable and can be tailored to meet specific performance criteria, this project sheds light on the impact of the most influential geometric characteristics to the mechanical response, in order to achieve the desired structural performance goals (stiffness, strength) and be compliant with the design specifications. This work reveals the prominent potential of architected materials for real-world engineering purposes, demonstrating a new and innovative alternative which outperforms traditional structural approaches and drives forward our current design practices.