The Architectural Woodwork Institute sets standards for appearance, engineering, fabrication, finishing and installation. Builders and architects need to be aware of three AWI grades when specifying work to be done:
Most architectural woodwork is custom grade, with premium grade reserved for special projects or focal points, and economy representing the minimum expectation of quality, workmanship, materials and installation.
For example, in custom grade millwork, the gap between doors, drawers or panels and frames must be 1/16" or less. In premium grade work, the tolerance is 1/32"; in economy, 3/32" is acceptable.