2. Criteria for choosing window wood

2.1 Solid wood

• Choice of appearance

  The manufacturer defines the appearance classes used during manufacture as specified in current standards:

  • NF EN 1611-1 : Appearance grading of softwood (sawn timber): spruce, fir, pine and Douglas fir (classes 0, 1, 2, 3 and 4 for 2 or 4 faces or edges) ;

  • NF EN 975-1 : Appearance grading of hardwoods (sawn timber): oak, beech (classes A, 1 (a and b for sawn timber), 2 and 3 ;

  • NF EN 942 (standard scheduled for revision): General classification of wood quality (in joinery)....