A 28 to 30 inch high work surface is optimal for writing and general purpose desk use (same as a dining table). A 24 to 28 inch high work surface is recommended if the desk will be used for typing.
A standing desk (versus a lap desk) is normally 30 to 60 inches wide and 20 to 30 inches deep. A conventional office desk is often about 60 inches wide and 30 inches deep.
The knee space under the desk should be 20 to 26 inches high, no less than 20 to 24 inches wide, and 12 to 15 inches deep.
Drawers installed below the work surface are generally larger than those above it. Upper drawers are typically used to store small items such as pens, paper clips, stamps, and personal effects. Lower drawers are used for larger items such as paper and are usually as long as the desk is deep. Lower drawers should be at least 12" wide in order to hold a standard piece of paper (letter size) lengthwise.
A drawer over the knee space can usually be no more than 4 inches deep because of limiting space between the work surface and the person's knees. Drawers behind the knee space or to the side of it are commonly 4 to 10 inches deep.
For aesthetics, deeper drawers should be placed toward the bottom of the desk and shallower drawers toward the top.
File drawers should be 10 inches deep. The width should be 12 inches for letter files and 15 inches for legal files (add 1/2" to width if hanger frames to be used).
The key design criteria in computer furniture is flexibility since it must provide for the proper placement of the various
computer components (cpu, keyboard, monitor, disk drives, printer, etc.) in relation to each other and to the computer operator. Provide for adjustability and modularity in the design. A workstation may be just a single, flat table although a more functional design provides three separate levels: one for the monitor, one for the keyboard, and one for a regular writing surface.
The line of sight angle from the keyboard to the top of the monitor should not exceed 60 degrees with the top of the monitor at or below eye level. For those accustomed to using a typewriter, the monitor should be placed closer to the keyboard.
With fingers resting on the keyboard, the angle between the upper arm and forearm should be 70 to 135 degrees. Most people find that 90 to 100 degrees is most comfortable. In general, the closer the keyboard is to the lap, the more comfortable typing will be. The keyboard height should be adjustable from 24 to 28 inches. Provide a flat area next to the keyboard and at the same height to accommodate a computer mouse.
The work surface should be between 20 and 30 inches deep and at least 24 inches wide. For maximum flexibility, the height should be that of a conventional writing desk, about 28 to 30 inches, with the keyboard resting on an adjustable shelf.
Seat height should be adjustable from 16 to 20 inches.
Many people prefer a printer stand that is lower than the work surface, about 18 to 24 inches, to enable easy access to the printer controls and paper.
Provide ample access holes for wires and heat dissipation.