Tracked Changes. Glass in building. Insulating glass units. Generalities, system description, rules for substitution, tolerances and visual quality|Buildings, Dimensional tolerances, Construction systems parts, Windows, Window glass, Environmental health, Sound insulation, Partitions, Doors, Quality assurance, Thermal insulation, Energy conservation, Transparency, Thermal insulating materials, Acoustic insulating materials, Rooflights, Marking, Glass, Approval testing, Glazing, Construction materials, Roofs, Curtain walling