A partition system for subdividing a building space includes a partition frame including a top frame member and intermediate frame members, cover panels releasably attached to the partition frame to cover the partition frame, and a floor channel including an upwardly facing channel for supporting the partition frame. An upper trim system includes a top cap configured to engage and cover the top frame member, and further includes an end cap configured to engage and cover an end of the intermediate frame members, and still further includes a corner piece for aesthetically interconnecting the top cap and the end cap. A lower trim system includes an elongated base trim side piece attached to the floor channel for covering a lower portion of the partition frame, and further includes a base trim end shoe attached to the partition frame for covering an end of the frame along the building floor. In a preferred form, the partition frame includes at least two horizontal frame members having cantilevered ends with notches formed therein. The end cap has a body configured to cover a vertical side edge of the partition frame at the ends. The end trim cap further has legs configured to engage the notches in the ends of the at least two horizonal frame members to retain the end cap to the partition frame. In a preferred form, the notches include barbs to fricitonally retain the legs. The partition frame includes a leveler attached to a bottom of the partition frame for leveling the partition frame. The base trim end piece includes a spring clip for holding the base trim piece to the partition frame proximate the building floor. The spring clip slidably vertically engages the base trim end piece so that the base trim end piece can be adjusted downwardly adjacent the building floor even when the leveler is adjusted to change a height of the partition frame.