A North American classification system organized by building elements and systems (foundations, superstructure, exterior enclosure) rather than by trade or work result. Where MasterFormat organizes information by trade (concrete, masonry, doors and windows), Uniformat groups the same building by what it physically is made of - substructure, shell, interiors, services - which makes it especially useful for early cost estimating and elemental quantity takeoffs, before trade-specific specifications even exist.