diff --git a/vtm-web-app/src/org/oscim/web/client/GwtMap.java b/vtm-web-app/src/org/oscim/web/client/GwtMap.java
index 20c2fbb0..250ebc28 100644
--- a/vtm-web-app/src/org/oscim/web/client/GwtMap.java
+++ b/vtm-web-app/src/org/oscim/web/client/GwtMap.java
@@ -39,7 +39,6 @@ import org.oscim.layers.tile.buildings.BuildingLayer;
 import org.oscim.layers.tile.buildings.S3DBTileLayer;
 import org.oscim.layers.tile.vector.VectorTileLayer;
 import org.oscim.layers.tile.vector.labeling.LabelLayer;
-import org.oscim.renderer.ExtrusionRenderer;
 import org.oscim.renderer.MapRenderer;
 import org.oscim.theme.StreamRenderTheme;
 import org.oscim.theme.VtmThemes;
@@ -151,7 +150,7 @@ class GwtMap extends GdxMap {
 
             if (!nobuildings && !s3db) {
                 mBuildingLayer = new BuildingLayer(mMap, l);
-                ((ExtrusionRenderer) mBuildingLayer.getRenderer()).setZLimit((float) 65536 / 10);
+                mBuildingLayer.getExtrusionRenderer().setZLimit((float) 65536 / 10);
                 mMap.layers().add(mBuildingLayer);
             }
 
@@ -174,7 +173,7 @@ class GwtMap extends GdxMap {
                     return;
                 }
 
-                ((ExtrusionRenderer) mBuildingLayer.getRenderer()).setZLimit((float) val / 10);
+                mBuildingLayer.getExtrusionRenderer().setZLimit((float) val / 10);
 
                 mMap.updateMap(true);
             }
diff --git a/vtm/src/org/oscim/layers/tile/buildings/BuildingLayer.java b/vtm/src/org/oscim/layers/tile/buildings/BuildingLayer.java
index b799a9c8..4c2dfe75 100644
--- a/vtm/src/org/oscim/layers/tile/buildings/BuildingLayer.java
+++ b/vtm/src/org/oscim/layers/tile/buildings/BuildingLayer.java
@@ -27,6 +27,7 @@ import org.oscim.layers.tile.ZoomLimiter;
 import org.oscim.layers.tile.vector.VectorTileLayer;
 import org.oscim.layers.tile.vector.VectorTileLayer.TileLoaderThemeHook;
 import org.oscim.map.Map;
+import org.oscim.renderer.ExtrusionRenderer;
 import org.oscim.renderer.OffscreenRenderer;
 import org.oscim.renderer.OffscreenRenderer.Mode;
 import org.oscim.renderer.bucket.ExtrusionBuckets;
@@ -65,6 +66,8 @@ public class BuildingLayer extends Layer implements TileLoaderThemeHook, ZoomLim
     // Can be replaced with Multimap in Java 8
     protected java.util.Map<Integer, List<BuildingElement>> mBuildings = new HashMap<>();
 
+    protected final ExtrusionRenderer mExtrusionRenderer;
+
     private final ZoomLimiter mZoomLimiter;
 
     protected final IRenderTheme mRenderTheme;
@@ -103,7 +106,7 @@ public class BuildingLayer extends Layer implements TileLoaderThemeHook, ZoomLim
         // Use zoomMin as zoomLimit to render buildings only once
         mZoomLimiter = new ZoomLimiter(tileLayer.getManager(), zoomMin, zoomMax, zoomMin);
 
-        mRenderer = new BuildingRenderer(tileLayer.tileRenderer(), mZoomLimiter, mesh, TRANSLUCENT);
+        mRenderer = mExtrusionRenderer = new BuildingRenderer(tileLayer.tileRenderer(), mZoomLimiter, mesh, TRANSLUCENT);
         if (POST_AA)
             mRenderer = new OffscreenRenderer(Mode.SSAO_FXAA, mRenderer);
 
@@ -243,6 +246,13 @@ public class BuildingLayer extends Layer implements TileLoaderThemeHook, ZoomLim
         return ebs;
     }
 
+    /**
+     * Get the ExtrusionRenderer for customization.
+     */
+    public ExtrusionRenderer getExtrusionRenderer() {
+        return mExtrusionRenderer;
+    }
+
     protected String getKeyOrDefault(String key) {
         if (mRenderTheme == null)
             return key;