Partition system for assembling a partition (3) such as a wall, that is composed of wooden beams (4) with two side faces (8,9) opposite one another extending in the longitudinal direction that determine the width of the beam (4) and with which the beams (4) can be assembled adjacent to one another, wherein connecting pieces (5) are provided to be fitted between adjacent beams (4) in order to keep the beams (4) from one another with a certain clearance (S) in the assembled state and that the connecting pieces (5) are kept at a fixed or practically fixed distance from one another by spacers (6).