What WingGap checks — and what it does not.
WingGap applies published wildlife biology guidelines to planar architectural glass through deterministic physical calculations.
The Physical Problem: Glass Perception
Birds do not perceive architectural glass as a solid barrier. Under natural daylight, glass either appears completely transparent (revealing indoor habitat or potted plants) or acts as an exterior mirror reflecting surrounding trees, sky, and greenery. Birds attempt to fly through what appears to be open space.
Decades of controlled tunnel tests and field monitoring demonstrate that visual markers must be applied to the exterior surface (Surface 1) of the glass. Interior markers often become invisible under direct sun reflections, severely compromising their protective effect.
- •Entered pane dimensions: Strict verification that width and height fall within supported planar bounds (100 mm to 3000 mm).
- •Fixed marker diameter: Minimum circular dot footprint of 6.35 mm (1/4 inch).
- •Regular-grid coordinates: Cell-centered canonical spacing across all columns and rows.
- •Center pitch: Center-to-center marker spacing verified against our internal engineering target of ≤45.0 mm.
- •Clear axial gaps: Glass openings between adjacent dot edges verified ≤50.8 mm (2 inches).
- •Boundary clearances: Perimeter margins from outer dot edges to pane boundaries verified ≤50.8 mm.
- •Collision probability scores: WingGap does not produce arbitrary statistical risk percentages.
- •Guaranteed prevention: No visual pattern can physically prevent 100% of bird collisions across all lighting, angles, and species.
- •Installed-treatment certification: WingGap generates a layout plan. It does not detect, verify, or certify finished physical installations.
- •Species-specific prediction: WingGap applies general geometric deterrence rather than avian ocular physiology modeling.
- •Unrestricted 2D largest openings: Calculations strictly evaluate orthogonal grid and boundary spans, not freeform diagonal openings.
The 45 mm Engineering Target
Published guidance (including American Bird Conservancy and CSA A460:19) recommends that clear spaces between pattern elements not exceed 50.8 mm (2 inches) in either direction.
WingGap enforces an internal center-to-center pitch target of ≤45.0 mm. With 6.35 mm circular dots, a 45.0 mm pitch yields a clear axial gap of:
WingGap uses a 45 mm center-pitch target, which creates planning headroom below the selected 50.8 mm clear-spacing check when 6.35 mm dots are used. This is an engineering convention, not a certified installation tolerance.
Key Guidance Sources
- • American Bird Conservancy (ABC): Bird-Friendly Building Standard & Threat Factor Evaluations
- • Canadian Standards Association (CSA): CSA A460:19 Bird-Friendly Building Design Standard
- • FLAP Canada: Fatal Light Awareness Program Visual Marker Guidelines
- • City of Toronto: Bird-Friendly Development Guidelines