Index: Ringtoets/Piping/src/Ringtoets.Piping.IO/Builders/SoilProfileBuilder2D.cs
===================================================================
diff -u -r33d4f4e7e5404dcc6470dd3d34168b30410109eb -r97c9e382dffcf32dc34d2e05e6a8a475b833ebd4
--- Ringtoets/Piping/src/Ringtoets.Piping.IO/Builders/SoilProfileBuilder2D.cs	(.../SoilProfileBuilder2D.cs)	(revision 33d4f4e7e5404dcc6470dd3d34168b30410109eb)
+++ Ringtoets/Piping/src/Ringtoets.Piping.IO/Builders/SoilProfileBuilder2D.cs	(.../SoilProfileBuilder2D.cs)	(revision 97c9e382dffcf32dc34d2e05e6a8a475b833ebd4)
@@ -1,66 +1,87 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
-
 using Ringtoets.Piping.Data;
-
 using Ringtoets.Piping.IO.Properties;
 
 namespace Ringtoets.Piping.IO.Builders
 {
     /// <summary>
     /// Constructs a 1d Soil Profile based on definitions of <see cref="SoilLayer2D"/>.
     /// </summary>
-    internal class SoilProfileBuilder2D : ISoilProfileBuilder
+    internal class SoilProfileBuilder2D
     {
         private readonly ICollection<PipingSoilLayer> layers = new Collection<PipingSoilLayer>();
+        private readonly double atX;
+        private readonly string profileName;
 
+        private double bottom;
+
         /// <summary>
         /// Creates a new instance of <see cref="SoilProfileBuilder2D"/> with the supposed name for the new <see cref="PipingSoilProfile"/>
         /// and the point at which a 1D profile should be obtained from the 2D profile.
         /// </summary>
         /// <param name="profileName">The name for the <see cref="PipingSoilProfile"/> constructed by the <see cref="SoilProfileBuilder2D"/>.</param>
         /// <param name="atX">The x position from which to obtain a 1D profile.</param>
+        /// <exception cref="ArgumentException">Thrown when <paramref name="atX"/> can not be used to determine intersections with
+        /// (is <see cref="double.NaN"/>).</exception>
         internal SoilProfileBuilder2D(string profileName, double atX)
         {
             if (double.IsNaN(atX))
             {
                 throw new ArgumentException(Resources.Error_SoilProfileBuilder_cant_determine_intersect_at_double_NaN);
             }
-            ProfileName = profileName;
-            AtX = atX;
-            Bottom = double.MaxValue;
+            this.profileName = profileName;
+            this.atX = atX;
+            bottom = double.MaxValue;
         }
 
         /// <summary>
-        /// Adds a new <see cref="SoilLayer2D"/> to the profile.
+        /// Creates a new instances of the <see cref="PipingSoilProfile"/> based on the layer definitions.
         /// </summary>
-        /// <param name="soilLayer">The <see cref="SoilLayer2D"/> to add to the profile.</param>
-        /// <returns>The <see cref="SoilProfileBuilder2D"/>.</returns>
-        internal SoilProfileBuilder2D Add(SoilLayer2D soilLayer)
+        /// <returns>A new <see cref="PipingSoilProfile"/>.</returns>
+        /// <exception cref="SoilProfileBuilderException">Thrown when trying to build a 
+        /// <see cref="PipingSoilProfile"/> and not having added any layers using <see cref="Add"/>.
+        /// </exception>
+        public PipingSoilProfile Build()
         {
-            double bottom;
-            foreach (PipingSoilLayer layer in soilLayer.AsPipingSoilLayers(AtX, out bottom))
+            try
             {
-                layers.Add(layer);
+                return new PipingSoilProfile(profileName, bottom, layers);
             }
-            Bottom = Math.Min(Bottom, bottom);
-            return this;
+            catch (ArgumentException e)
+            {
+                throw new SoilProfileBuilderException(e.Message, e);
+            }
         }
 
         /// <summary>
-        /// Creates a new instance of <see cref="PipingSoilProfile"/>.
+        /// Adds a new <see cref="SoilLayer2D"/> to the profile.
         /// </summary>
-        /// <returns>A new <see cref="PipingSoilProfile"/>.</returns>
-        public PipingSoilProfile Build()
+        /// <param name="soilLayer">The <see cref="SoilLayer2D"/> to add to the profile.</param>
+        /// <returns>The <see cref="SoilProfileBuilder2D"/>.</returns>
+        /// <exception cref="SoilProfileBuilderException">Thrown when the <paramref name="soilLayer"/>'s geometry
+        /// contains vertical segments the X-coordinate given for the construction of the 
+        /// <see cref="SoilProfileBuilder2D(string,double)"/>.</exception>
+        internal SoilProfileBuilder2D Add(SoilLayer2D soilLayer)
         {
-            return new PipingSoilProfile(ProfileName, Bottom, layers);
-        }
+            double newBottom;
 
-        private double Bottom { get; set; }
+            try
+            {
+                var pipingSoilLayers = soilLayer.AsPipingSoilLayers(atX, out newBottom);
+                foreach (PipingSoilLayer layer in pipingSoilLayers)
+                {
+                    layers.Add(layer);
+                }
+            }
+            catch (SoilLayer2DConversionException e)
+            {
+                throw new SoilProfileBuilderException(e.Message, e);
+            }
 
-        private double AtX { get; set; }
-
-        private string ProfileName { get; set; }
+            bottom = Math.Min(bottom, newBottom);
+            return this;
+        }
     }
 }
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