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This assessment regulates how the visible surface of installed glass is evaluated.
It applies to clear, coated, through‑colored glass, toughened glass, and laminated glass.
There are limitations for glass with inserts, patterned/cast glass, and attack‑resistant or fire‑protective glazing.

If no special use is specified, the glass is assumed to be standard façade glass with covered edges.
Evaluation is always done from the external viewing direction.

The inspection is carried out by looking through the glass at the background, not at the surface.
The glass must not be marked during inspection.

Viewing distance: 1 meter, with a maximum viewing angle of 45°.
Lighting: diffuse daylight (e.g., overcast sky), no direct sunlight or artificial light.
For exterior glazing, the normal accessible viewing distance applies (minimum 1 m).

Only defects that are visible under these conditions without reflections are considered.

The pane is assessed using defined inspection zones.
It is assumed that all four edges are installed like in standard façade glazing.
Inspection zones must be agreed upon before ordering.

Rebate Zone (F):

At least 18 mm wide, or the area covered by the insulating glass edge/spacer.

Edge Zone (R):

Outer 10% of the visible glass area.

Main Zone (H):

The remaining central visible area.

Glass always has an inherent color (often slightly green).
Coatings or multi‑layer laminates may intensify this effect.
Color variations between different glass batches are normal.
If a specific product type is required, it must be clearly defined when ordering.

Below is the technical defect table.
For layperson understanding, here is the simplified guidance:

• Tiny points ≤ 0.5 mm: Allowed everywhere.
• Medium points > 0.5–1 mm: Allowed if not concentrated in one area.
• Larger defects:
  • Main zone: max. 2 per m²
  • Edge zone: max. 3 per m²
  • Rebate zone: no limits
• Scratches:
  • Main zone: up to 3 scratches ≤ 15 mm per 2 m²
  • Edge zone: up to 3 scratches ≤ 30 mm per m²
  • Rebate zone: no limits
• Hairline scratches:
  • Not allowed in high concentration in main/edge zones
  • Always allowed in rebate zone
• Internal residues (insulating glass only):
  • Main zone: not allowed
  • Edge zone: some limited residue allowed
  • Rebate zone: not applicable

(Technical defect definitions remain unchanged below.)

Type of defect	Main zone (H)	Edge zone (R)	Rebate zone (F)
Inclusions, bubbles, spots, stains, ... 0,5 mm Ø (3)	no restriction (with ODF (5) max. 3mm)	no restriction (with ODF (5) max. 3mm)	no restriction
Inclusions, bubbles, spots, stains, ... > 0.5 - 1 mm Ø (3)	no restriction (with ODF (5) max. 3mm) no high density	no restriction (with ODF (5) max. 3mm) no high density	no restriction
Inclusions, bubbles, spots, stains, ... > 0,1 mm Ø (3)(5)	average max. 2 defects a < 2mm Ø per qm no high density	average max. 3 defects a < 3mm Ø per qm no high density	no restriction
Scratches (3)	Inividual length max. 15 mm, max 3 per 2qm	individual length max. 30 mm, max. 3 per qm	no restriction
Hairline scratches (3)(4)	Not permitted in high density (2)	Not permitted in high density (2)	no restriction
Residues in the cavity (insulating glass)	Not permitted	Punctual: max 1 defect> 3 mm Ø per 1m edge length flat: max. 1 defect> 3qcm per 5 qm (color whitish, grey translucent, transp..)	not applicable

(1): Hairline scratches = not palpable damage of the surface
(2) High density: more than 4 defects in a circle Ø 20 cm
(3) Laminates and laminated safety glass: when using structures with more than 2 glass layers, the number of
      permissibilities in the zones R en H increases by 50% per further layer (rounded off to full defects)
(4) Maximum size of defects with ODF (5) 5mm with core defect < 2 mm, ODF (5) 6 mm with core defect < 3 mm
(5) ODF = optically distorted fields