Costs of maintenance and operation are important part of the Life cycle costs. This paper describes development and validation of a new model for predicting average annual costs of maintenance and operations for the University buildings in Osijek with similar building characteristics. The model is developed based on historical cost data records obtained from 13 University buildings in Osijek for time period of 12 years starting from 1998. The model was tested at two new sets of data, in buildings outside of Osijek. The proposed operating and maintenance costs model requires reduced amount of data for predicting annual maintenance and operations costs of University buildings of similar building characteristics and highlights statistically significant data required for costs prediction. The model contains only few elements but yet can predict operating and maintenance costs. The proposed model enables maintenance and operations cost estimates already at the initial design phase.