Impervious Calcs v1.0

What It Does

• Pervious & Impervious Coverage — Tracks grass, landscaping, paved surfaces, and manually flagged impervious islands. Areas update live as you add or remove entities.
• Building Coverage & GFA — Assign floor counts to building footprints and automatically calculate Gross Floor Area (GFA) per building.
• Floor Area Ratio (FAR) — FAR is computed automatically from your building footprints and site boundary.
• Canopy Coverage — Track tree canopy polygons as their own category with a separate area total.
• Retention Basin Tracking — Tag basins separately, with an option to count them toward the pervious total.
• Impervious Area Subtraction — Mark paved islands or hardscape within a pervious zone; they automatically reduce the pervious total.
• Live Polyline Drawing — Draw new coverage polygons directly from the panel with a live preview as you pick points, then confirm or cancel.
• Persistent Data — All coverage data is saved inside the .dwg file itself — no external files, no sidecar data.
• One-Click Copy — Copy any individual total (area in SF/AC, percentage, FAR, GFA) to the clipboard for pasting into reports or permit applications.