This paper deals with the basics of the so-called “Massive Timber Construction“ (MTC) system. The paper is focused to the design of MTC system (mainly design of floors, shear walls and connections) which is made from the relatively new wood-based product “Cross Laminated Timber” (CLT). CLT consists of several layers built-up with boards. Their assembly in orthogonal directions allow them to produce elements with big dimensions. Currently, no regulations for the design of CLT-elements are given in the European standards. Nevertheless mechanical parameters of CLT-elements can be determined on the basis of the properties of the single layers as is shown in the paper. It is expected that CLT will play an important role in the future use of wood in single and multi-storey buildings.