A height adjustable work surface is described that may be utilized as a standalone desk or table, or integrated with a larger work surface to provide selective height adjustability to only a portion of a work surface. The height adjustable work surface preferably utilizes a modular trapezoidal frame structure, including trapezoid tube weldments, corner castings and machined hardened connector pins. The lift mechanism preferably includes parallelogram linkages, pneumatic gas cylinders, sliding brake bar mechanism and brake release handles to provide height adjustment functionality.