diff --git a/src/plan/toElevation.test.ts b/src/plan/toElevation.test.ts
index 64a486f..972b850 100644
--- a/src/plan/toElevation.test.ts
+++ b/src/plan/toElevation.test.ts
@@ -398,6 +398,52 @@ describe("toElevation — Öffnungen: Verdeckung + Reveal-Schatten", () => {
     expect(symCount("drehkipp")).toBe(4); // Dreh (2) + Kipp (2)
   });
 
+  it("Kämpfer-Zeilen (mullionRows): teilen das Glasfeld horizontal (Glas + Trennlinien)", () => {
+    const base = elevationProject({ overhang: false });
+    const mk = (mullionRows: number): Project =>
+      ({
+        ...base,
+        windowTypes: [
+          {
+            id: "wt",
+            name: "F",
+            kind: "fest",
+            wingCount: 1,
+            glazing: "einfach",
+            frameWidth: 0.06,
+            mullionRows,
+            defaultSillHeight: 0.9,
+            defaultWidth: 1,
+            defaultHeight: 1.2,
+          },
+        ],
+        openings: [
+          {
+            id: "op",
+            type: "opening",
+            hostWallId: "NEAR",
+            categoryCode: "21",
+            kind: "window",
+            typeId: "wt",
+            position: 1.5,
+            width: 1,
+            height: 1.2,
+            sillHeight: 0.9,
+          },
+        ],
+      }) as unknown as Project;
+    const glassCount = (rows: number): number => {
+      const p = mk(rows);
+      const plan = generateElevationPlan(p, p.drawingLevels[1])!;
+      // Glasflächen = weiss/blau gefüllte Polygone mit Kontur, keine Öffnung/Rahmen.
+      return plan.primitives.filter(
+        (pr) => pr.kind === "polygon" && pr.fill === "#9fc2d9",
+      ).length;
+    };
+    expect(glassCount(1)).toBe(1); // fest, 1 Feld
+    expect(glassCount(3)).toBe(3); // in 3 Zeilen geteilt
+  });
+
   it("Reveal-Schatten: shadows=true erzeugt Öffnungs-Schattenbänder, false keine", () => {
     const project = openingProject();
     const level = project.drawingLevels[1];
diff --git a/src/plan/toElevation.ts b/src/plan/toElevation.ts
index 2ae0d6b..bf801bd 100644
--- a/src/plan/toElevation.ts
+++ b/src/plan/toElevation.ts
@@ -772,8 +772,20 @@ function collectOpenings(project: Project, frame: ElevationFrame): ProjectedOpen
         const gB = fa1 - gU;
         const gz0 = fz + gV;
         const gz1 = fieldTop - gV;
+        // Kämpfer-/Sprossen-Zeilen (mullionRows): das Glasfeld wird in `rows`
+        // horizontale Scheiben geteilt (analog zum 3D, s. toWalls3d), mit einer
+        // Trennlinie je Zeilengrenze über die Glasbreite. 1 = ungeteilt (bisher).
+        const rows = Math.max(1, Math.round(wt?.mullionRows ?? 1));
         if (gB - gA > 1e-6 && gz1 - gz0 > 1e-6) {
-          pr.glass.push(rect(pr.pts, gA, gB, gz0, gz1));
+          for (let r = 0; r < rows; r++) {
+            const rz0 = gz0 + ((gz1 - gz0) * r) / rows + (r > 0 ? gV / 2 : 0);
+            const rz1 = gz0 + ((gz1 - gz0) * (r + 1)) / rows - (r < rows - 1 ? gV / 2 : 0);
+            if (rz1 - rz0 > 1e-6) pr.glass.push(rect(pr.pts, gA, gB, rz0, rz1));
+          }
+          for (let r = 1; r < rows; r++) {
+            const rz = gz0 + ((gz1 - gz0) * r) / rows;
+            pr.divisions.push([quadAt(pr.pts, gA, rz), quadAt(pr.pts, gB, rz)]);
+          }
         }
         // Trennlinie zum nächsten Feld (ausser am Rand).
         if (fa1 < 1 - fa - 1e-6) {