diff --git a/app.js b/app.js
index f66f7f1..30b155d 100644
--- a/app.js
+++ b/app.js
@@ -2178,6 +2178,19 @@ document.addEventListener('DOMContentLoaded', async () => {
         // 2. Clear existing owner statuses
         state.ownerStatuses = {};
 
+        // 2.5 Clear dynamic overlays and bakedData to ensure project isolation
+        Object.keys(overlays).forEach(key => {
+            if (!['Variante A', 'Variante B', 'Variante C', 'Hilfs-Geometrien', 'Abstände (Gleiches Layout)'].includes(key)) {
+                if (state.map.hasLayer(overlays[key])) {
+                    state.map.removeLayer(overlays[key]);
+                }
+                layerControl.removeLayer(overlays[key]);
+                delete overlays[key];
+            }
+        });
+        state.bakedData = {};
+        updateLegend();
+
         try {
             // 3. Load dynamic layers for new project
             await initDynamicLayers();