Index: Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Data.Test/ClosingStructureTest.cs
===================================================================
diff -u -r6e717246d970bc18500da686a51f82101296ff46 -r1fc75a751bf039a27a14b30d855b3aebe98f8512
--- Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Data.Test/ClosingStructureTest.cs	(.../ClosingStructureTest.cs)	(revision 6e717246d970bc18500da686a51f82101296ff46)
+++ Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.Data.Test/ClosingStructureTest.cs	(.../ClosingStructureTest.cs)	(revision 1fc75a751bf039a27a14b30d855b3aebe98f8512)
@@ -194,55 +194,55 @@
 
             VariationCoefficientLogNormalDistribution storageStructureArea = structure.StorageStructureArea;
             Assert.AreEqual(2, storageStructureArea.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, storageStructureArea.Mean, storageStructureArea.Mean.GetAccuracy());
+            Assert.IsNaN(storageStructureArea.Mean);
             Assert.AreEqual(2, storageStructureArea.CoefficientOfVariation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.1, storageStructureArea.CoefficientOfVariation, storageStructureArea.CoefficientOfVariation.GetAccuracy());
 
             LogNormalDistribution allowedLevelIncreaseStorage = structure.AllowedLevelIncreaseStorage;
             Assert.AreEqual(2, allowedLevelIncreaseStorage.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, allowedLevelIncreaseStorage.Mean, allowedLevelIncreaseStorage.Mean.GetAccuracy());
+            Assert.IsNaN(allowedLevelIncreaseStorage.Mean);
             Assert.AreEqual(2, allowedLevelIncreaseStorage.StandardDeviation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.1, allowedLevelIncreaseStorage.StandardDeviation, allowedLevelIncreaseStorage.StandardDeviation.GetAccuracy());
 
             NormalDistribution widthFlowApertures = structure.WidthFlowApertures;
             Assert.AreEqual(2, widthFlowApertures.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, widthFlowApertures.Mean, widthFlowApertures.Mean.GetAccuracy());
+            Assert.IsNaN(widthFlowApertures.Mean);
             Assert.AreEqual(2, widthFlowApertures.StandardDeviation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.2, widthFlowApertures.StandardDeviation, widthFlowApertures.StandardDeviation.GetAccuracy());
 
             NormalDistribution levelCrestStructureNotClosing = structure.LevelCrestStructureNotClosing;
             Assert.AreEqual(2, levelCrestStructureNotClosing.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, levelCrestStructureNotClosing.Mean, levelCrestStructureNotClosing.Mean.GetAccuracy());
+            Assert.IsNaN(levelCrestStructureNotClosing.Mean);
             Assert.AreEqual(2, levelCrestStructureNotClosing.StandardDeviation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.05, levelCrestStructureNotClosing.StandardDeviation, levelCrestStructureNotClosing.StandardDeviation.GetAccuracy());
 
             NormalDistribution insideWaterLevel = structure.InsideWaterLevel;
             Assert.AreEqual(2, insideWaterLevel.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, insideWaterLevel.Mean, insideWaterLevel.Mean.GetAccuracy());
+            Assert.IsNaN(insideWaterLevel.Mean);
             Assert.AreEqual(2, insideWaterLevel.StandardDeviation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.1, insideWaterLevel.StandardDeviation, insideWaterLevel.StandardDeviation.GetAccuracy());
 
             NormalDistribution thresholdHeightOpenWeir = structure.ThresholdHeightOpenWeir;
             Assert.AreEqual(2, thresholdHeightOpenWeir.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, thresholdHeightOpenWeir.Mean, thresholdHeightOpenWeir.Mean.GetAccuracy());
+            Assert.IsNaN(thresholdHeightOpenWeir.Mean);
             Assert.AreEqual(2, thresholdHeightOpenWeir.StandardDeviation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.1, thresholdHeightOpenWeir.StandardDeviation, thresholdHeightOpenWeir.StandardDeviation.GetAccuracy());
 
             LogNormalDistribution areaFlowApertures = structure.AreaFlowApertures;
             Assert.AreEqual(2, areaFlowApertures.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, areaFlowApertures.Mean, areaFlowApertures.Mean.GetAccuracy());
+            Assert.IsNaN(areaFlowApertures.Mean);
             Assert.AreEqual(2, areaFlowApertures.StandardDeviation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.1, areaFlowApertures.StandardDeviation, areaFlowApertures.StandardDeviation.GetAccuracy());
 
             VariationCoefficientLogNormalDistribution criticalOvertoppingDischarge = structure.CriticalOvertoppingDischarge;
             Assert.AreEqual(2, criticalOvertoppingDischarge.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, criticalOvertoppingDischarge.Mean, criticalOvertoppingDischarge.Mean.GetAccuracy());
+            Assert.IsNaN(criticalOvertoppingDischarge.Mean);
             Assert.AreEqual(2, criticalOvertoppingDischarge.CoefficientOfVariation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.15, criticalOvertoppingDischarge.CoefficientOfVariation, criticalOvertoppingDischarge.CoefficientOfVariation.GetAccuracy());
 
             LogNormalDistribution flowWidthAtBottomProtection = structure.FlowWidthAtBottomProtection;
             Assert.AreEqual(2, flowWidthAtBottomProtection.Mean.NumberOfDecimalPlaces);
-            Assert.AreEqual(double.NaN, flowWidthAtBottomProtection.Mean, flowWidthAtBottomProtection.Mean.GetAccuracy());
+            Assert.IsNaN(flowWidthAtBottomProtection.Mean);
             Assert.AreEqual(2, flowWidthAtBottomProtection.StandardDeviation.NumberOfDecimalPlaces);
             Assert.AreEqual(0.05, flowWidthAtBottomProtection.StandardDeviation, flowWidthAtBottomProtection.StandardDeviation.GetAccuracy());
 
Index: Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.IO.Test/ClosingStructuresImporterTest.cs
===================================================================
diff -u -r006e2461c3c2f32451e7f8715e3cece92230a27a -r1fc75a751bf039a27a14b30d855b3aebe98f8512
--- Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.IO.Test/ClosingStructuresImporterTest.cs	(.../ClosingStructuresImporterTest.cs)	(revision 006e2461c3c2f32451e7f8715e3cece92230a27a)
+++ Ringtoets/ClosingStructures/test/Ringtoets.ClosingStructures.IO.Test/ClosingStructuresImporterTest.cs	(.../ClosingStructuresImporterTest.cs)	(revision 1fc75a751bf039a27a14b30d855b3aebe98f8512)
@@ -29,6 +29,7 @@
 using NUnit.Framework;
 using Ringtoets.ClosingStructures.Data;
 using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.TestUtil;
 using Ringtoets.Common.IO.FileImporters;
 
 namespace Ringtoets.ClosingStructures.IO.Test
@@ -227,7 +228,18 @@
             });
             Assert.IsTrue(importResult);
             Assert.AreEqual(1, importTarget.Count);
-            // TODO assert default values.
+
+            var defaultStructure = new ClosingStructure(new ClosingStructure.ConstructionProperties()
+            {
+                Name = "test",
+                Location = new Point2D(0, 0),
+                Id = "id"
+            });
+            ClosingStructure importedStructure = importTarget[0];
+            DistributionAssert.AreEqual(defaultStructure.StorageStructureArea, importedStructure.StorageStructureArea);
+            DistributionAssert.AreEqual(defaultStructure.LevelCrestStructureNotClosing, importedStructure.LevelCrestStructureNotClosing);
+            DistributionAssert.AreEqual(defaultStructure.AreaFlowApertures, importedStructure.AreaFlowApertures);
+            Assert.AreEqual(defaultStructure.FailureProbabilityReparation, importedStructure.FailureProbabilityReparation);
         }
 
         private static ReferenceLine CreateReferenceLine()
Index: Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.IO.Test/HeightStructuresImporterTest.cs
===================================================================
diff -u -r6ab99400f0ba68a5669bcea64fc8d9b99ac2b48e -r1fc75a751bf039a27a14b30d855b3aebe98f8512
--- Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.IO.Test/HeightStructuresImporterTest.cs	(.../HeightStructuresImporterTest.cs)	(revision 6ab99400f0ba68a5669bcea64fc8d9b99ac2b48e)
+++ Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.IO.Test/HeightStructuresImporterTest.cs	(.../HeightStructuresImporterTest.cs)	(revision 1fc75a751bf039a27a14b30d855b3aebe98f8512)
@@ -23,7 +23,6 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Linq.Expressions;
 using Core.Common.Base;
 using Core.Common.Base.Geometry;
 using Core.Common.TestUtil;
@@ -170,7 +169,6 @@
         [Test]
         public void Import_MissingParameters_LogWarningAndContinueImportWithDefaultValues()
         {
-
             // Setup
             string filePath = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.HeightStructures.IO,
                                                          Path.Combine(nameof(HeightStructuresImporter), "Kunstwerken.shp"));