A modular system (30) for framing and supporting work surfaces and storage units includes a pair of generally rectangular end frames (32) having side member (36) each defining inside and outside channel sections. The end frames (32) are releasably secured together by lateral connectors (34) which are adjustably clamped along the inside channel portions of the end frame side members (36). The lateral connectors (34) are adapted for supporting storage units by means of inverted J-shaped hooks 70. The work surfaces are independently supported on arms (84) which are adjustably clamped along the outside channel sections of the end frame side members (36) in order to facilitate rearrangement and adjustment in accordance with the requirements of laboratories and the like. A modular system (120) adapted for use with existing structural walls (128) is also disclosed.