Due to the growing need to preserve our planet and to reduce carbon dioxide (CO2) emissions during construction, the use of the only CO2-absorbing material, timber, is increasingly being imposed. Recently, the design and construction of mass-produced buildings using cross-laminated timber (CLT) and glued laminated timber (GLT) has risen sharply. In addition to the requirement of reducing CO2 emissions, there is a need of minimizing construction time and usage of construction machinery, which has led to the development of prefabricated timber construction systems. This may ultimately result in reduced costs and higher construction speeds, compared to standard commonly non-combustible materials, and structures. This doctoral thesis deals with innovative hollow glue-laminated timber elements intended for prefabricated construction systems. Comparing this innovative system with existing ones, the main system's features and behavior of the constituent elements i.e., the hollow glue-laminated timber elements, in ambient and fire conditions have been presented. Fire safety greatly contributes to the user's feeling of safety, and it is a key parameter for the selection of building materials. The combustibility of timber is one of the main reasons to have strict restrictions on timber for usage as a building material, especially for multi-storey buildings. At the end of the life cycle, timber releases stored CO2 into the atmosphere by decomposition or combustion. Therefore, the main prerequisite for the use of timber in buildings is to ensure adequate fire resistance, using passive and active fire protection measures. Due to the geometry of the hollow GLT elements and the thin vertical timber parts between the hollows, the fire load can lead to irregular residual cross-sections with greater charring depths in comparison to the standard GLT elements. Mechanical and fire load along with the geometrical and material characteristics of timber elements play a crucial role in researching their resistance. This thesis provides an overview of the possibilities and challenges in achieving this goal, guided by the principles of fire engineering. The mechanical and fire performance of innovative hollow glue-laminated timber elements has not been investigated yet and is the main goal of this thesis. The main hypotheses are as follows: H1 : Experimental research and numerical analysis will enable the determination of the influence of the geometrical and material characteristics on the mechanical and fire performance of hollow glue-laminated elements. H2 : By perforating the cross-section area of timber elements up to 35 %, a minimum of 60 % of the load-carrying capacity of the full cross-section timber elements can be reached. H3 : By perforating the cross-section area of timber elements up to 35 %, a minimum of 30 % of the fire resistance capacity of the full cross-section timber elements can be reached, and by applying fire protection in the form of fire retardants, or non-combustible materials infill in the first row of hollows, favorable effects on fire resistance of hollow glue-laminated timber elements can be achieved compared to the fire resistance of the full cross-section timber elements.