Index: Ringtoets/GrassCoverErosionOutwards/src/Ringtoets.GrassCoverErosionOutwards.Data/GrassCoverErosionOutwardsFailureMechanismExtensions.cs
===================================================================
diff -u -r1e14ee40087ad0c42f889f6ee86c13bf6d7d192b -r5d0dfa9a8b6e98ede2791a93ed50d48ce6ada072
--- Ringtoets/GrassCoverErosionOutwards/src/Ringtoets.GrassCoverErosionOutwards.Data/GrassCoverErosionOutwardsFailureMechanismExtensions.cs	(.../GrassCoverErosionOutwardsFailureMechanismExtensions.cs)	(revision 1e14ee40087ad0c42f889f6ee86c13bf6d7d192b)
+++ Ringtoets/GrassCoverErosionOutwards/src/Ringtoets.GrassCoverErosionOutwards.Data/GrassCoverErosionOutwardsFailureMechanismExtensions.cs	(.../GrassCoverErosionOutwardsFailureMechanismExtensions.cs)	(revision 5d0dfa9a8b6e98ede2791a93ed50d48ce6ada072)
@@ -24,6 +24,8 @@
 using System.ComponentModel;
 using System.Linq;
 using Core.Common.Base.Data;
+using Ringtoets.AssemblyTool.Data;
+using Ringtoets.Common.Data.AssemblyTool;
 using Ringtoets.Common.Data.AssessmentSection;
 using Ringtoets.Common.Data.FailureMechanism;
 using Ringtoets.Common.Data.Hydraulics;
@@ -38,8 +40,8 @@
         /// <summary>
         /// Gets the assessment level for a <see cref="HydraulicBoundaryLocation"/> based on <see cref="FailureMechanismCategoryType"/>.
         /// </summary>
-        /// <param name="assessmentSection">The assessment section to get the assessment level from.</param>
         /// <param name="failureMechanism">The failure mechanism to get the assessment level from.</param>
+        /// <param name="assessmentSection">The assessment section to get the assessment level from.</param>
         /// <param name="hydraulicBoundaryLocation">The hydraulic boundary location to get the assessment level for.</param>
         /// <param name="categoryType">The category type to use while obtaining the assessment level.</param>
         /// <returns>The assessment level or <see cref="RoundedDouble.NaN"/> when:
@@ -104,6 +106,68 @@
             return GetAssessmentLevelFromCalculations(hydraulicBoundaryLocation, calculations);
         }
 
+        /// <summary>
+        /// Gets the norm based on <see cref="FailureMechanismCategoryType"/>.
+        /// </summary>
+        /// <param name="failureMechanism">The failure mechanism to get the norm from.</param>
+        /// <param name="assessmentSection">The assessment section to get the norm from.</param>
+        /// <param name="categoryType">The category type to use while obtaining the norm.</param>
+        /// <returns>The norm corresponding to the provided category type.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="failureMechanism"/>
+        /// or <paramref name="assessmentSection"/> is <c>null</c>.</exception>
+        /// <exception cref="InvalidEnumArgumentException">Thrown when <paramref name="categoryType"/>
+        /// is an invalid <see cref="FailureMechanismCategoryType"/>.</exception>
+        /// <exception cref="NotSupportedException">Thrown when <paramref name="categoryType"/>
+        /// is a valid but unsupported <see cref="FailureMechanismCategoryType"/>.</exception>
+        public static double GetNorm(this GrassCoverErosionOutwardsFailureMechanism failureMechanism,
+                                     IAssessmentSection assessmentSection,
+                                     FailureMechanismCategoryType categoryType)
+        {
+            if (failureMechanism == null)
+            {
+                throw new ArgumentNullException(nameof(failureMechanism));
+            }
+
+            if (assessmentSection == null)
+            {
+                throw new ArgumentNullException(nameof(assessmentSection));
+            }
+
+            if (!Enum.IsDefined(typeof(FailureMechanismCategoryType), categoryType))
+            {
+                throw new InvalidEnumArgumentException(nameof(categoryType),
+                                                       (int) categoryType,
+                                                       typeof(FailureMechanismCategoryType));
+            }
+
+            IEnumerable<FailureMechanismSectionAssemblyCategory> categories = AssemblyToolCategoriesFactory.CreateFailureMechanismSectionAssemblyCategories(
+                assessmentSection.FailureMechanismContribution.SignalingNorm,
+                assessmentSection.FailureMechanismContribution.LowerLimitNorm,
+                failureMechanism.Contribution,
+                failureMechanism.GeneralInput.N);
+
+            switch (categoryType)
+            {
+                case FailureMechanismCategoryType.MechanismSpecificFactorizedSignalingNorm:
+                    return categories.First(c => c.Group == FailureMechanismSectionAssemblyCategoryGroup.IIv)
+                                     .LowerBoundary;
+                case FailureMechanismCategoryType.MechanismSpecificSignalingNorm:
+                    return categories.First(c => c.Group == FailureMechanismSectionAssemblyCategoryGroup.IIIv)
+                                     .LowerBoundary;
+                case FailureMechanismCategoryType.MechanismSpecificLowerLimitNorm:
+                    return categories.First(c => c.Group == FailureMechanismSectionAssemblyCategoryGroup.IVv)
+                                     .LowerBoundary;
+                case FailureMechanismCategoryType.LowerLimitNorm:
+                    return categories.First(c => c.Group == FailureMechanismSectionAssemblyCategoryGroup.Vv)
+                                     .LowerBoundary;
+                case FailureMechanismCategoryType.FactorizedLowerLimitNorm:
+                    return categories.First(c => c.Group == FailureMechanismSectionAssemblyCategoryGroup.VIv)
+                                     .LowerBoundary;
+                default:
+                    throw new NotSupportedException();
+            }
+        }
+
         private static RoundedDouble GetAssessmentLevelFromCalculations(HydraulicBoundaryLocation hydraulicBoundaryLocation,
                                                                         IEnumerable<HydraulicBoundaryLocationCalculation> calculations)
         {