diff --git a/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutPointWall.java b/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutPointWall.java
index 85e33facc..2235dd2c6 100644
--- a/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutPointWall.java
+++ b/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutPointWall.java
@@ -9,7 +9,6 @@
 package org.noise_planet.noisemodelling.pathfinder.profilebuilder;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import org.locationtech.jts.geom.Coordinate;
 import org.locationtech.jts.geom.LineSegment;
@@ -37,9 +36,9 @@ public class CutPointWall  extends CutPoint {
     /** This point encounter this kind of limit
      * - We can enter or exit a polygon
      * - pass a line (a wall without width) */
-    public enum INTERSECTION_TYPE { AREA_ENTER, AREA_EXIT, LINE_ENTER_EXIT}
+    public enum INTERSECTION_TYPE {BUILDING_ENTER, BUILDING_EXIT, THIN_WALL_ENTER_EXIT}
 
-    public INTERSECTION_TYPE intersectionType = INTERSECTION_TYPE.LINE_ENTER_EXIT;
+    public INTERSECTION_TYPE intersectionType = INTERSECTION_TYPE.THIN_WALL_ENTER_EXIT;
 
     /** Database primary key value of the obstacle */
     @JsonInclude(JsonInclude.Include.NON_NULL)
diff --git a/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutProfile.java b/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutProfile.java
index 7b12e5098..6adae4ecb 100644
--- a/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutProfile.java
+++ b/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/CutProfile.java
@@ -171,36 +171,46 @@ public static List<Coordinate> computePtsGround(List<CutPoint> pts, List<Integer
         if(pts.isEmpty()) {
             return pts2D;
         }
-        // keep track of the obstacle under our current position. If -1 there is only ground below
-        int overObstacleIndex = pts.get(0) instanceof CutPointWall ? ((CutPointWall)pts.get(0)).processedWallIndex : -1;
-        for (int i=0; i < pts.size(); i++) {
-            CutPoint cut = pts.get(i);
+        // keep track of the obstacle under our current position.
+        boolean overArea = false;
+        for (CutPoint cut : pts) {
+            if (cut instanceof CutPointWall) {
+                CutPointWall cutPointWall = (CutPointWall) cut;
+                if (cutPointWall.intersectionType.equals(CutPointWall.INTERSECTION_TYPE.BUILDING_EXIT)) {
+                    overArea = true;
+                } else {
+                    break;
+                }
+            }
+        }
+        for (CutPoint cut : pts) {
             if (cut instanceof CutPointGroundEffect) {
-                if(index != null) {
+                if (index != null) {
                     index.add(pts2D.size() - 1);
                 }
                 continue;
             }
-            Coordinate coordinate;
             if (cut instanceof CutPointWall) {
-                if(Double.compare(cut.getCoordinate().z, cut.getzGround()) == 0) {
-                    // current position is at the ground level in front of or behind the first/last wall
-                    if(overObstacleIndex == -1) {
-                        overObstacleIndex = ((CutPointWall) cut).processedWallIndex;
-                    } else {
-                        overObstacleIndex = -1;
-                    }
+                // Z ground profile must add intermediate ground points before adding the top level of building/wall
+                CutPointWall cutPointWall = (CutPointWall) cut;
+                if (cutPointWall.intersectionType.equals(CutPointWall.INTERSECTION_TYPE.BUILDING_ENTER) ||
+                        cutPointWall.intersectionType.equals(CutPointWall.INTERSECTION_TYPE.THIN_WALL_ENTER_EXIT)) {
+                    pts2D.add(new Coordinate(cut.getCoordinate().x, cut.getCoordinate().y, cut.getzGround()));
+                    overArea = true;
+                }
+                pts2D.add(new Coordinate(cut.getCoordinate().x, cut.getCoordinate().y, cut.getCoordinate().z));
+                if (cutPointWall.intersectionType.equals(CutPointWall.INTERSECTION_TYPE.BUILDING_EXIT) ||
+                        cutPointWall.intersectionType.equals(CutPointWall.INTERSECTION_TYPE.THIN_WALL_ENTER_EXIT)) {
+                    pts2D.add(new Coordinate(cut.getCoordinate().x, cut.getCoordinate().y, cut.getzGround()));
+                    overArea = false;
                 }
-                // Take the obstacle altitude instead of the ground level
-                coordinate = new Coordinate(cut.getCoordinate().x, cut.getCoordinate().y, cut.getCoordinate().z);
             } else {
-                coordinate = new Coordinate(cut.getCoordinate().x, cut.getCoordinate().y, cut.getzGround());
-            }
-            // we will ignore topographic point if we are over a building
-            if(!(overObstacleIndex >= 0 && cut instanceof CutPointTopography)) {
-                pts2D.add(coordinate);
+                // we will ignore topographic point if we are over a building
+                if (!(overArea && cut instanceof CutPointTopography)) {
+                    pts2D.add(new Coordinate(cut.getCoordinate().x, cut.getCoordinate().y, cut.getzGround()));
+                }
             }
-            if(index != null) {
+            if (index != null) {
                 index.add(pts2D.size() - 1);
             }
         }
diff --git a/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/ProfileBuilder.java b/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/ProfileBuilder.java
index c745eef35..f81d8799a 100644
--- a/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/ProfileBuilder.java
+++ b/noisemodelling-pathfinder/src/main/java/org/noise_planet/noisemodelling/pathfinder/profilebuilder/ProfileBuilder.java
@@ -12,7 +12,6 @@
 import org.locationtech.jts.algorithm.Angle;
 import org.locationtech.jts.algorithm.CGAlgorithms3D;
 import org.locationtech.jts.geom.Coordinate;
-import org.locationtech.jts.geom.CoordinateSequence;
 import org.locationtech.jts.geom.Envelope;
 import org.locationtech.jts.geom.Geometry;
 import org.locationtech.jts.geom.GeometryFactory;
@@ -1025,7 +1024,7 @@ private boolean processWall(int processedWallIndex, Coordinate intersection, Wal
 
         CutPointWall cutPointWall = new CutPointWall(processedWallIndex,
                 intersection, facetLine.getLineSegment(), facetLine.alphas);
-        cutPointWall.intersectionType = CutPointWall.INTERSECTION_TYPE.LINE_ENTER_EXIT;
+        cutPointWall.intersectionType = CutPointWall.INTERSECTION_TYPE.THIN_WALL_ENTER_EXIT;
         if(facetLine.primaryKey >= 0) {
             cutPointWall.setPk(facetLine.primaryKey);
         }
@@ -1059,9 +1058,9 @@ private boolean processBuilding(int processedWallIndex, Coordinate intersection,
         Coordinate exteriorPoint = exteriorVector.add(Vector2D.create(intersection)).toCoordinate();
         // exterior point closer to source so we know that we enter the building
         if(exteriorPoint.distance(fullLine.p0) < intersection.distance(fullLine.p0)) {
-            wallCutPoint.intersectionType = CutPointWall.INTERSECTION_TYPE.AREA_ENTER;
+            wallCutPoint.intersectionType = CutPointWall.INTERSECTION_TYPE.BUILDING_ENTER;
         } else {
-            wallCutPoint.intersectionType = CutPointWall.INTERSECTION_TYPE.AREA_EXIT;
+            wallCutPoint.intersectionType = CutPointWall.INTERSECTION_TYPE.BUILDING_EXIT;
         }
 
         if (zRayReceiverSource <= intersection.z) {
diff --git a/noisemodelling-pathfinder/src/test/java/org/noise_planet/noisemodelling/pathfinder/ProfileBuilderTest.java b/noisemodelling-pathfinder/src/test/java/org/noise_planet/noisemodelling/pathfinder/ProfileBuilderTest.java
index 3a514be27..48184e60e 100644
--- a/noisemodelling-pathfinder/src/test/java/org/noise_planet/noisemodelling/pathfinder/ProfileBuilderTest.java
+++ b/noisemodelling-pathfinder/src/test/java/org/noise_planet/noisemodelling/pathfinder/ProfileBuilderTest.java
@@ -21,11 +21,13 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.noise_planet.noisemodelling.pathfinder.PathFinderTest.assertZProfil;
 
 /**
  * Test class dedicated to {@link ProfileBuilder}.
@@ -294,6 +296,62 @@ public void testRelativeSourceLineProjection() throws ParseException {
                 new Coordinate(120.0, 33.16, 1.0),
                 new Coordinate(185.0, 46.84, 11.0),
                 new Coordinate(200.0, 50.0, 11.0));
-        PathFinderTest.assertZProfil(expectedProfile, Arrays.asList(scene.sourceGeometries.get(0).getCoordinates()));
+        assertZProfil(expectedProfile, Arrays.asList(scene.sourceGeometries.get(0).getCoordinates()));
+    }
+
+
+    @Test
+    public void test2DGroundProfile() {
+
+        //Profile building (from TC15)
+        ProfileBuilder profileBuilder = new ProfileBuilder()
+                .addBuilding(new Coordinate[]{
+                        new Coordinate(55.0, 5.0, 8),
+                        new Coordinate(65.0, 5.0, 8),
+                        new Coordinate(65.0, 15.0, 8),
+                        new Coordinate(55.0, 15.0, 8),
+                })
+                .addBuilding(new Coordinate[]{
+                        new Coordinate(70.0, 14.5, 12),
+                        new Coordinate(80.0, 10.2, 12),
+                        new Coordinate(80.0, 20.2, 12),
+                })
+                .addBuilding(new Coordinate[]{
+                        new Coordinate(90.1, 19.5, 10),
+                        new Coordinate(93.3, 17.8, 10),
+                        new Coordinate(87.3, 6.6, 10),
+                        new Coordinate(84.1, 8.3, 10),
+                });
+        profileBuilder.addGroundEffect(0, 100, 0.0, 150, 0.5);
+        profileBuilder.setzBuildings(true);
+        profileBuilder.finishFeeding();
+
+        CutProfile cutProfile = profileBuilder.getProfile(new Coordinate(50,10,1), new Coordinate(100, 15, 5));
+
+        assertEquals(9, cutProfile.cutPoints.size());
+
+        List<Coordinate> zProfile = cutProfile.computePts2DGround();
+
+        /* Table 148 */
+        List<Coordinate> expectedZProfile = new ArrayList<>();
+        expectedZProfile.add(new Coordinate(0.00, 0.00));
+        expectedZProfile.add(new Coordinate(5.02, 0.00));
+        expectedZProfile.add(new Coordinate(5.02, 8.00));
+        expectedZProfile.add(new Coordinate(15.07, 8.0));
+        expectedZProfile.add(new Coordinate(15.08, 0.0));
+        expectedZProfile.add(new Coordinate(24.81, 0.0));
+        expectedZProfile.add(new Coordinate(24.81, 12.0));
+        expectedZProfile.add(new Coordinate(30.15, 12.0));
+        expectedZProfile.add(new Coordinate(30.15, 0.00));
+        expectedZProfile.add(new Coordinate(37.19, 0.0));
+        expectedZProfile.add(new Coordinate(37.19, 10.0));
+        expectedZProfile.add(new Coordinate(41.52, 10.0));
+        expectedZProfile.add(new Coordinate(41.52, 0.0));
+        expectedZProfile.add(new Coordinate(50.25, 0.0));
+
+        //Assertion
+        assertZProfil(expectedZProfile, zProfile);
+
+
     }
 }