The present work focuses on probability-based safety-checking formats suitable for implementation in codes for the purpose of the assessment of existing buildings. As an alternative to the current ap- proach in the European code based on applying the conf idence factors, a semi-probabilistic approach is pro- posed based on applying a bias factor and a dispersion factor inside safety checking formats for both static and dynamic analyses. In this work, an efficient simula tion-based Bayesian method is used in order to esti- mate the factors for the safety-checking formats for the case-study structure for different knowledge levels and different outcomes of the tests and inspections. It can be argued that, if the so-called bias factor and the dispersion factor can be calibrated for various building types and different outcomes of tests and inspections, they may offer an acceptable alterna tive to confidence factors in lieu of rigorous case-specific probability- based assessment of existing buildings