diff --git a/Assets/Scripts/tools/Extruder.cs b/Assets/Scripts/tools/Extruder.cs
index 7b181827..657baa1a 100644
--- a/Assets/Scripts/tools/Extruder.cs
+++ b/Assets/Scripts/tools/Extruder.cs
@@ -90,6 +90,8 @@ public class Extruder : MonoBehaviour
         /// </summary>
         private bool isSnapping = false;
 
+        private Face nearestFace;
+
         /// <summary>
         ///   Every tool is implemented as MonoBehaviour, which means it may do no work in its constructor.
         ///   As such, this setup method must be called before the tool is used for it to have a valid state.
@@ -106,7 +108,7 @@ public void Setup(Model model, ControllerMain controllerMain, PeltzerController
             controllerMain.ControllerActionHandler += ControllerEventHandler;
         }
 
-        private ExtrusionOperation.ExtrusionParams BuildExtrusionParams()
+        private ExtrusionOperation.ExtrusionParams BuildExtrusionParams(bool flipped)
         {
             // Note: ExtrusionParams is a struct, so this is stack allocated and doesn't generate garbage.
             ExtrusionOperation.ExtrusionParams extrusionParams = new ExtrusionOperation.ExtrusionParams();
@@ -116,6 +118,7 @@ private ExtrusionOperation.ExtrusionParams BuildExtrusionParams()
             extrusionParams.rotationPivotModel = peltzerController.LastPositionModel;
             extrusionParams.rotationModel =
               peltzerController.LastRotationModel * Quaternion.Inverse(extrusionBeginOrientation);
+            extrusionParams.flipped = flipped;
             return extrusionParams;
         }
 
@@ -172,7 +175,14 @@ private void Update()
                     triggerUpToRelease = true;
                 }
 
-                ExtrusionOperation.ExtrusionParams extrusionParams = BuildExtrusionParams();
+                bool towards = true;
+                if (nearestFace != null)
+                {
+                    var faceVector = nearestFace.normal;
+                    var dragVector = peltzerController.LastPositionModel - extrusionBeginPosition;
+                    towards = Vector3.Dot(faceVector, dragVector) > 0;
+                }
+                ExtrusionOperation.ExtrusionParams extrusionParams = BuildExtrusionParams(!towards);
                 foreach (ExtrusionOperation operation in extrusions)
                 {
                     operation.UpdateExtrudeGuide(extrusionParams);
@@ -397,7 +407,15 @@ private void ReleaseMesh()
             List<Command> commands = new List<Command>();
             Dictionary<int, MMesh> modifiedMeshes = new Dictionary<int, MMesh>();
             Dictionary<int, HashSet<Vertex>> newVerticesInModifiedMeshes = new Dictionary<int, HashSet<Vertex>>();
-            ExtrusionOperation.ExtrusionParams extrusionParams = BuildExtrusionParams();
+
+            bool towards = true;
+            if (nearestFace != null)
+            {
+                var faceVector = nearestFace.normal;
+                var dragVector = peltzerController.LastPositionModel - extrusionBeginPosition;
+                towards = Vector3.Dot(faceVector, dragVector) > 0;
+            }
+            ExtrusionOperation.ExtrusionParams extrusionParams = BuildExtrusionParams(!towards);
 
             foreach (ExtrusionOperation extrusion in extrusions)
             {
@@ -473,6 +491,9 @@ private void ControllerEventHandler(object sender, ControllerEventArgs args)
                         return;
                     }
                 }
+
+                nearestFace = selector.GetNearestFace(peltzerController.LastPositionModel);
+
                 triggerUpToRelease = false;
                 waitingToDetermineReleaseType = true;
                 triggerDownTime = Time.time;
diff --git a/Assets/Scripts/tools/ExtrusionOperation.cs b/Assets/Scripts/tools/ExtrusionOperation.cs
index 480333e3..5c632a65 100644
--- a/Assets/Scripts/tools/ExtrusionOperation.cs
+++ b/Assets/Scripts/tools/ExtrusionOperation.cs
@@ -49,6 +49,7 @@ public struct ExtrusionParams
         // Indicates the point about which the extruded face should be rotated, AFTER the translation.
         // This is in MODEL space.
         public Vector3 rotationPivotModel;
+        public bool flipped;
     }
 
     /// <summary>
@@ -476,7 +477,7 @@ public static List<ExtrusionSideVertices> BuildExtrusionSides(
         if (extrusionParams.lockToNormal)
         {
             var extrudedPoint = GridUtils.SnapToGrid(extrusionParams.translationModel);
-            projectedDelta = mesh.rotation * face.normal * extrudedPoint.magnitude;
+            projectedDelta = mesh.rotation * face.normal * (extrudedPoint.magnitude * (extrusionParams.flipped ? -1 : 1));
         }
         else
         {
diff --git a/Assets/Scripts/tools/Selector.cs b/Assets/Scripts/tools/Selector.cs
index 7c5a6df6..1451e1d5 100644
--- a/Assets/Scripts/tools/Selector.cs
+++ b/Assets/Scripts/tools/Selector.cs
@@ -1563,5 +1563,20 @@ public void AddSelectedMeshForTest(int meshId)
         {
             selectedMeshes.Add(meshId);
         }
+
+        public Face GetNearestFace(Vector3 pos)
+        {
+            float selectionThreshold = faceClosenessThreshold * INCREASED_SELECTION_FACTOR;
+            spatialIndex.FindFacesClosestTo(pos, selectionThreshold,
+                false, out List<DistancePair<FaceKey>> temp);
+            if (temp.Count == 0)
+            {
+                return null;
+            }
+            var facekey = temp[0].value;
+            var mesh = model.GetMesh(facekey.meshId);
+            var face = mesh.GetFace(facekey.faceId);
+            return face;
+        }
     }
 }