Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.Forms.Test/TreeNodeInfos/GrassCoverErosionInwardsCalculationGroupContextTreeNodeInfoTest.cs
===================================================================
diff -u -r2ea2a436a8c2b2ea2d2737113e9519bd22d5734a -r7cebb168afee29822b64f213045a21520b38ade0
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.Forms.Test/TreeNodeInfos/GrassCoverErosionInwardsCalculationGroupContextTreeNodeInfoTest.cs	(.../GrassCoverErosionInwardsCalculationGroupContextTreeNodeInfoTest.cs)	(revision 2ea2a436a8c2b2ea2d2737113e9519bd22d5734a)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.Forms.Test/TreeNodeInfos/GrassCoverErosionInwardsCalculationGroupContextTreeNodeInfoTest.cs	(.../GrassCoverErosionInwardsCalculationGroupContextTreeNodeInfoTest.cs)	(revision 7cebb168afee29822b64f213045a21520b38ade0)
@@ -597,23 +597,19 @@
             var nodeData = new GrassCoverErosionInwardsCalculationGroupContext(group,
                                                                                failureMechanism,
                                                                                assessmentSectionMock);
-
             var calculationItem = new GrassCoverErosionInwardsCalculation(new GeneralGrassCoverErosionInwardsInput(), new GeneralNormProbabilityInput())
             {
                 Name = "Nieuwe berekening"
             };
-
             var observerMock = mocks.StrictMock<IObserver>();
-            observerMock.Expect(o => o.UpdateObserver());
-
             var treeViewControlMock = mocks.StrictMock<TreeViewControl>();
 
+            observerMock.Expect(o => o.UpdateObserver());
             guiMock.Expect(cmp => cmp.Get(nodeData, treeViewControlMock)).Return(menuBuilder);
 
             mocks.ReplayAll();
 
             group.Children.Add(calculationItem);
-
             nodeData.Attach(observerMock);
 
             var contextMenu = info.ContextMenuStrip(nodeData, null, treeViewControlMock);
Index: Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Data/Properties/Resources.Designer.cs
===================================================================
diff -u -r7e310cacb9c4875ce8e2d60af68a46c4c8b55041 -r7cebb168afee29822b64f213045a21520b38ade0
--- Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 7e310cacb9c4875ce8e2d60af68a46c4c8b55041)
+++ Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Data/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 7cebb168afee29822b64f213045a21520b38ade0)
@@ -22,7 +22,7 @@
     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "4.0.0.0")]
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
-    internal class Resources {
+    public class Resources {
         
         private static global::System.Resources.ResourceManager resourceMan;
         
@@ -36,7 +36,7 @@
         ///   Returns the cached ResourceManager instance used by this class.
         /// </summary>
         [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
-        internal static global::System.Resources.ResourceManager ResourceManager {
+        public static global::System.Resources.ResourceManager ResourceManager {
             get {
                 if (object.ReferenceEquals(resourceMan, null)) {
                     global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Ringtoets.HeightStructures.Data.Properties.Resources", typeof(Resources).Assembly);
@@ -51,7 +51,7 @@
         ///   resource lookups using this strongly typed resource class.
         /// </summary>
         [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
-        internal static global::System.Globalization.CultureInfo Culture {
+        public static global::System.Globalization.CultureInfo Culture {
             get {
                 return resourceCulture;
             }
@@ -63,7 +63,7 @@
         /// <summary>
         ///   Looks up a localized string similar to Nieuwe berekening.
         /// </summary>
-        internal static string HeightStructuresCalculation_DefaultName {
+        public static string HeightStructuresCalculation_DefaultName {
             get {
                 return ResourceManager.GetString("HeightStructuresCalculation_DefaultName", resourceCulture);
             }
@@ -72,7 +72,7 @@
         /// <summary>
         ///   Looks up a localized string similar to HTKW.
         /// </summary>
-        internal static string HeightStructuresFailureMechanism_Code {
+        public static string HeightStructuresFailureMechanism_Code {
             get {
                 return ResourceManager.GetString("HeightStructuresFailureMechanism_Code", resourceCulture);
             }
@@ -81,7 +81,7 @@
         /// <summary>
         ///   Looks up a localized string similar to Kunstwerken - Hoogte kunstwerk.
         /// </summary>
-        internal static string HeightStructuresFailureMechanism_DisplayName {
+        public static string HeightStructuresFailureMechanism_DisplayName {
             get {
                 return ResourceManager.GetString("HeightStructuresFailureMechanism_DisplayName", resourceCulture);
             }
Index: Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Data/Ringtoets.HeightStructures.Data.csproj
===================================================================
diff -u -r47d80506f9f8166de93579dbba94e57f4101927b -r7cebb168afee29822b64f213045a21520b38ade0
--- Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Data/Ringtoets.HeightStructures.Data.csproj	(.../Ringtoets.HeightStructures.Data.csproj)	(revision 47d80506f9f8166de93579dbba94e57f4101927b)
+++ Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Data/Ringtoets.HeightStructures.Data.csproj	(.../Ringtoets.HeightStructures.Data.csproj)	(revision 7cebb168afee29822b64f213045a21520b38ade0)
@@ -73,7 +73,7 @@
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="Properties\Resources.resx">
-      <Generator>ResXFileCodeGenerator</Generator>
+      <Generator>PublicResXFileCodeGenerator</Generator>
       <LastGenOutput>Resources.Designer.cs</LastGenOutput>
     </EmbeddedResource>
   </ItemGroup>
Index: Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Plugin/HeightStructuresGuiPlugin.cs
===================================================================
diff -u -re2986d74885385074ad0f6d164a722c0c7e39a8b -r7cebb168afee29822b64f213045a21520b38ade0
--- Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Plugin/HeightStructuresGuiPlugin.cs	(.../HeightStructuresGuiPlugin.cs)	(revision e2986d74885385074ad0f6d164a722c0c7e39a8b)
+++ Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Plugin/HeightStructuresGuiPlugin.cs	(.../HeightStructuresGuiPlugin.cs)	(revision 7cebb168afee29822b64f213045a21520b38ade0)
@@ -29,11 +29,13 @@
 using Ringtoets.Common.Data.AssessmentSection;
 using Ringtoets.Common.Data.Calculation;
 using Ringtoets.Common.Data.FailureMechanism;
+using Ringtoets.Common.Forms.Helpers;
 using Ringtoets.Common.Forms.PresentationObjects;
 using Ringtoets.Common.Forms.TreeNodeInfos;
 using Ringtoets.HeightStructures.Data;
 using Ringtoets.HeightStructures.Forms.PresentationObjects;
 using RingtoetsCommonFormsResources = Ringtoets.Common.Forms.Properties.Resources;
+using HeightStructuresDataResources = Ringtoets.HeightStructures.Data.Properties.Resources;
 using HeightStructuresFormsResources = Ringtoets.HeightStructures.Forms.Properties.Resources;
 
 namespace Ringtoets.HeightStructures.Plugin
@@ -208,7 +210,7 @@
             }
 
             builder.AddCreateCalculationGroupItem(group)
-                   .AddCreateCalculationItem(context, groupContext => { })
+                   .AddCreateCalculationItem(context, AddCalculation)
                    .AddSeparator()
                    .AddPerformAllCalculationsInGroupItem(group, context, (calculationGroup, groupContext) => { }, groupContext => "")
                    .AddClearAllCalculationOutputInGroupItem(group)
@@ -239,6 +241,16 @@
             parentGroupContext.NotifyObservers();
         }
 
+        private static void AddCalculation(HeightStructuresCalculationGroupContext context)
+        {
+            var calculation = new HeightStructuresCalculation
+            {
+                Name = NamingHelper.GetUniqueName(context.WrappedData.Children, HeightStructuresDataResources.HeightStructuresCalculation_DefaultName, c => c.Name)
+            };
+            context.WrappedData.Children.Add(calculation);
+            context.WrappedData.NotifyObservers();
+        }
+
         #endregion
 
         #region HeightStructuresCalculationContext TreeNodeInfo
Index: Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Forms.Test/TreeNodeInfos/HeightStructuresCalculationGroupContextTreeNodeInfoTest.cs
===================================================================
diff -u -r8b294a80cb40bb01ffe437ad314baec0d038d160 -r7cebb168afee29822b64f213045a21520b38ade0
--- Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Forms.Test/TreeNodeInfos/HeightStructuresCalculationGroupContextTreeNodeInfoTest.cs	(.../HeightStructuresCalculationGroupContextTreeNodeInfoTest.cs)	(revision 8b294a80cb40bb01ffe437ad314baec0d038d160)
+++ Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Forms.Test/TreeNodeInfos/HeightStructuresCalculationGroupContextTreeNodeInfoTest.cs	(.../HeightStructuresCalculationGroupContextTreeNodeInfoTest.cs)	(revision 7cebb168afee29822b64f213045a21520b38ade0)
@@ -369,6 +369,50 @@
         }
 
         [Test]
+        public void ContextMenuStrip_ClickOnAddCalculationItem_AddCalculationToCalculationGroupAndNotifyObservers()
+        {
+            // Setup
+            var menuBuilder = new CustomItemsOnlyContextMenuBuilder();
+            var group = new CalculationGroup();
+            var failureMechanism = new HeightStructuresFailureMechanism();
+            var assessmentSectionMock = mocks.StrictMock<IAssessmentSection>();
+            var nodeData = new HeightStructuresCalculationGroupContext(group,
+                                                                               failureMechanism,
+                                                                               assessmentSectionMock);
+            var calculation = new HeightStructuresCalculation
+            {
+                Name = "Nieuwe berekening"
+            };
+            var observerMock = mocks.StrictMock<IObserver>();
+            var treeViewControlMock = mocks.StrictMock<TreeViewControl>();
+
+            observerMock.Expect(o => o.UpdateObserver());
+            guiMock.Expect(cmp => cmp.Get(nodeData, treeViewControlMock)).Return(menuBuilder);
+
+            mocks.ReplayAll();
+
+            group.Children.Add(calculation);
+            nodeData.Attach(observerMock);
+
+            var contextMenu = info.ContextMenuStrip(nodeData, null, treeViewControlMock);
+
+            // Precondition
+            Assert.AreEqual(1, group.Children.Count);
+
+            // Call
+            contextMenu.Items[contextMenuAddCalculationIndexRootGroup].PerformClick();
+
+            // Assert
+            Assert.AreEqual(2, group.Children.Count);
+            var newlyAddedItem = group.Children.Last();
+            Assert.IsInstanceOf<HeightStructuresCalculation>(newlyAddedItem);
+            Assert.AreEqual("Nieuwe berekening (1)", newlyAddedItem.Name,
+                            "An item with the same name default name already exists, therefore '(1)' needs to be appended.");
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
         public void OnNodeRemoved_NestedCalculationGroup_RemoveGroupAndNotifyObservers()
         {
             // Setup