The present paper gives an overview about different aspects related to system focused reliability based design of timber structures. At first the principles of structural reliability were introduced, including the probability of failure, robustness and vulnerability. In the following the influence of the natural growth characteristics of timber, the specific characteristics of different types of beam type elements, the influence of connections as well as the influence of system effects between structural members on the reliability are discussed. A simple Finite Element model is presented that is capable to account for varying element properties and connection stiffness. A small case study on a trussed girder was performed in order to investigate the effect of different statically systems and the number of structural members.