diff --git a/src/NwcIO/Model/Clash/NwcClashBcfExporter.cs b/src/NwcIO/Model/Clash/NwcClashBcfExporter.cs
index c9817c9..84fe8fe 100644
--- a/src/NwcIO/Model/Clash/NwcClashBcfExporter.cs
+++ b/src/NwcIO/Model/Clash/NwcClashBcfExporter.cs
@@ -60,15 +60,51 @@ public static void Save(string path, NwcClashTest test, string? projectName = nu
     /// </summary>
     public static void Write(Stream stream, NwcClashTest test, string projectName = "Navisworks Clash Coordination")
     {
-        ArgumentNullException.ThrowIfNull(stream);
         ArgumentNullException.ThrowIfNull(test);
+        Write(stream, [test], projectName);
+    }
+
+    /// <summary>
+    /// Saves clash tests, including both standalone results and grouped clashes, to one BCF 2.1 archive file.
+    /// </summary>
+    public static void Save(string path, IEnumerable<NwcClashTest> tests, string projectName = "Navisworks Clash Coordination")
+    {
+        ArgumentNullException.ThrowIfNull(path);
+        ArgumentNullException.ThrowIfNull(tests);
+
+        string? dir = Path.GetDirectoryName(Path.GetFullPath(path));
+        if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir))
+        {
+            Directory.CreateDirectory(dir);
+        }
+
+        using var fs = File.Create(path);
+        Write(fs, tests, projectName);
+    }
+
+    /// <summary>
+    /// Writes clash tests, including both standalone results and grouped clashes, to one BCF 2.1 zip stream:
+    /// a topic per clash group and a topic per clash that is in no group.
+    /// </summary>
+    public static void Write(Stream stream, IEnumerable<NwcClashTest> tests, string projectName = "Navisworks Clash Coordination")
+    {
+        ArgumentNullException.ThrowIfNull(stream);
+        ArgumentNullException.ThrowIfNull(tests);
 
         using var archive = new ZipArchive(stream, ZipArchiveMode.Create, leaveOpen: true);
 
         // 1. Root bcf.version
         WriteBcfVersion(archive);
 
-        // 2. Export Clash Groups as unified topics
+        foreach (var test in tests)
+        {
+            WriteTest(archive, test, projectName);
+        }
+    }
+
+    private static void WriteTest(ZipArchive archive, NwcClashTest test, string projectName)
+    {
+        // Export Clash Groups as unified topics
         foreach (var group in test.Groups)
         {
             string topicFolder = group.GroupGuid.ToString("D");
@@ -88,7 +124,7 @@ public static void Write(Stream stream, NwcClashTest test, string projectName =
             }
         }
 
-        // 3. Export standalone clash results
+        // Export standalone clash results
         foreach (var clash in test.Results)
         {
             string topicFolder = clash.ResultGuid.ToString("D");
diff --git a/src/NwcIO/Model/Clash/NwcClashMatrix.cs b/src/NwcIO/Model/Clash/NwcClashMatrix.cs
index 02720ab..96a2a33 100644
--- a/src/NwcIO/Model/Clash/NwcClashMatrix.cs
+++ b/src/NwcIO/Model/Clash/NwcClashMatrix.cs
@@ -61,7 +61,8 @@ public sealed class NwcClashMatrixCell
     public NwcClashTest? ExecutedTest { get; set; }
 
     public int ClashCount => ExecutedTest?.TotalClashCount ?? 0;
-    public IReadOnlyList<NwcClashResult> Clashes => ExecutedTest?.Results ?? (IReadOnlyList<NwcClashResult>)Array.Empty<NwcClashResult>();
+    public IReadOnlyList<NwcClashResult> Clashes =>
+        ExecutedTest?.AllClashes.ToList() ?? (IReadOnlyList<NwcClashResult>)Array.Empty<NwcClashResult>();
 
     public NwcClashMatrixCell() { }
 
@@ -335,10 +336,10 @@ public void SaveJson(string filePath, bool indent = true)
             writer.WriteNumber("tolerance", c.Tolerance);
             writer.WriteNumber("clashesCount", c.ClashCount);
 
-            if (c.ExecutedTest is not null && c.ExecutedTest.Results.Count > 0)
+            if (c.ExecutedTest is not null && c.ExecutedTest.TotalClashCount > 0)
             {
                 writer.WriteStartArray("clashes");
-                foreach (var clash in c.ExecutedTest.Results)
+                foreach (var clash in c.ExecutedTest.AllClashes)
                 {
                     writer.WriteStartObject();
                     writer.WriteString("name", clash.Name);
@@ -365,11 +366,11 @@ public void SaveJson(string filePath, bool indent = true)
     public void SaveBcf(string filePath)
     {
         ArgumentNullException.ThrowIfNull(filePath);
-        var allClashes = Cells
+        var tests = Cells
             .Where(c => c.ExecutedTest is not null)
-            .SelectMany(c => c.ExecutedTest!.Results)
+            .Select(c => c.ExecutedTest!)
             .ToList();
 
-        NwcClashBcfExporter.Save(filePath, allClashes, Name);
+        NwcClashBcfExporter.Save(filePath, tests, Name);
     }
 }
diff --git a/src/NwcIO/Model/NwcAssembly.cs b/src/NwcIO/Model/NwcAssembly.cs
index c562f6b..071d1dc 100644
--- a/src/NwcIO/Model/NwcAssembly.cs
+++ b/src/NwcIO/Model/NwcAssembly.cs
@@ -344,7 +344,7 @@ public void ExportClashReportXml(string path)
     /// <summary>Exports detected clash results to a buildingSMART BCF 2.1 zip archive (.bcfzip).</summary>
     public void ExportClashBcf(string path)
     {
-        Clash.NwcClashBcfExporter.Save(path, ClashTests.SelectMany(t => t.Results), Name);
+        Clash.NwcClashBcfExporter.Save(path, ClashTests, Name);
     }
 
     /// <summary>Creates a Navisworks Federated Project Manifest (NWF) representation of this assembly.</summary>
diff --git a/src/NwcIO/NwcDocument.cs b/src/NwcIO/NwcDocument.cs
index 124ec96..1f38945 100644
--- a/src/NwcIO/NwcDocument.cs
+++ b/src/NwcIO/NwcDocument.cs
@@ -452,8 +452,7 @@ public void ExportClashBcf(string path, string? testName = null)
         var tests = string.IsNullOrEmpty(testName)
             ? ClashTests
             : ClashTests.Where(t => string.Equals(t.Name, testName, StringComparison.OrdinalIgnoreCase));
-        var clashes = tests.SelectMany(t => t.Results);
-        Model.Clash.NwcClashBcfExporter.Save(path, clashes, Path.GetFileNameWithoutExtension(FileInfo.SourcePath ?? "Model"));
+        Model.Clash.NwcClashBcfExporter.Save(path, tests, Path.GetFileNameWithoutExtension(FileInfo.SourcePath ?? "Model"));
     }
 
     /// <summary>Exports detected clash results to a BCF 2.1 stream.</summary>
@@ -462,8 +461,7 @@ public void ExportClashBcf(Stream stream, string? testName = null)
         var tests = string.IsNullOrEmpty(testName)
             ? ClashTests
             : ClashTests.Where(t => string.Equals(t.Name, testName, StringComparison.OrdinalIgnoreCase));
-        var clashes = tests.SelectMany(t => t.Results);
-        Model.Clash.NwcClashBcfExporter.Write(stream, clashes, Path.GetFileNameWithoutExtension(FileInfo.SourcePath ?? "Model"));
+        Model.Clash.NwcClashBcfExporter.Write(stream, tests, Path.GetFileNameWithoutExtension(FileInfo.SourcePath ?? "Model"));
     }
 
     /// <summary>Loads clash detective tests and results from a Navisworks Clash Report XML file.</summary>
diff --git a/tests/NwcIO.Tests/ClashGroupingTests.cs b/tests/NwcIO.Tests/ClashGroupingTests.cs
index d2e7e3e..daa6a81 100644
--- a/tests/NwcIO.Tests/ClashGroupingTests.cs
+++ b/tests/NwcIO.Tests/ClashGroupingTests.cs
@@ -220,6 +220,95 @@ public void NwcClashBcfExporter_ExportsGroupedClashesToBcfZip()
         Assert.NotNull(viewpointEntry);
     }
 
+    private static NwcClashTest CreateGroupedTest()
+    {
+        var test = new NwcClashTest("Grouped");
+        test.Results.AddRange(
+        [
+            CreateClash("c1", new Vector3d(0, 0, 0), -0.05),
+            CreateClash("c2", new Vector3d(0.2, 0, 0), -0.05),
+            CreateClash("c3", new Vector3d(50, 0, 0), -0.05),
+            CreateClash("c4", new Vector3d(50.3, 0, 0), -0.05),
+            CreateClash("c5", new Vector3d(200, 0, 0), -0.05),
+        ]);
+        NwcClashGrouper.GroupByProximity(test, clusterDistance: 2.0, minClusterSize: 2);
+        Assert.Equal(2, test.Groups.Count);
+        Assert.Single(test.Results);
+        return test;
+    }
+
+    private static int CountTopics(Stream bcf)
+    {
+        bcf.Position = 0;
+        using var zip = new ZipArchive(bcf, ZipArchiveMode.Read, leaveOpen: true);
+        return zip.Entries.Count(e => e.FullName.EndsWith("/markup.bcf", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public void Document_ExportClashBcf_IncludesGroupedClashes()
+    {
+        var doc = new NwcDocumentBuilder().SetFileInfo("Model.nwc").Build();
+        doc.ClashTests.Add(CreateGroupedTest());
+
+        using var ms = new MemoryStream();
+        doc.ExportClashBcf(ms);
+
+        Assert.Equal(3, CountTopics(ms)); // 2 groups + 1 ungrouped clash
+    }
+
+    [Fact]
+    public void Assembly_And_Matrix_ExportClashBcf_IncludeGroupedClashes()
+    {
+        var assembly = NwcAssembly.Create("Asm");
+        assembly.ClashTests.Add(CreateGroupedTest());
+        var matrix = new NwcClashMatrix("Matrix");
+        matrix.Cells.Add(new NwcClashMatrixCell("A", "B") { ExecutedTest = CreateGroupedTest() });
+
+        string assemblyPath = Path.Combine(Path.GetTempPath(), $"nwcio_{Guid.NewGuid():N}.bcfzip");
+        string matrixPath = Path.Combine(Path.GetTempPath(), $"nwcio_{Guid.NewGuid():N}.bcfzip");
+        try
+        {
+            assembly.ExportClashBcf(assemblyPath);
+            matrix.SaveBcf(matrixPath);
+
+            using (var fs = File.OpenRead(assemblyPath)) Assert.Equal(3, CountTopics(fs));
+            using (var fs = File.OpenRead(matrixPath)) Assert.Equal(3, CountTopics(fs));
+        }
+        finally
+        {
+            File.Delete(assemblyPath);
+            File.Delete(matrixPath);
+        }
+    }
+
+    [Fact]
+    public void Matrix_ClashesAndJson_IncludeGroupedClashes()
+    {
+        var cell = new NwcClashMatrixCell("A", "B") { ExecutedTest = CreateGroupedTest() };
+        var matrix = new NwcClashMatrix("Matrix");
+        matrix.Cells.Add(cell);
+
+        Assert.Equal(5, cell.Clashes.Count);
+
+        string path = Path.Combine(Path.GetTempPath(), $"nwcio_{Guid.NewGuid():N}.json");
+        try
+        {
+            matrix.SaveJson(path);
+            using var json = System.Text.Json.JsonDocument.Parse(File.ReadAllText(path));
+            var written = json.RootElement.EnumerateObject()
+                .Select(p => p.Value)
+                .Where(v => v.ValueKind == System.Text.Json.JsonValueKind.Array)
+                .SelectMany(a => a.EnumerateArray())
+                .Single(c => c.TryGetProperty("clashesCount", out _));
+            Assert.Equal(5, written.GetProperty("clashesCount").GetInt32());
+            Assert.Equal(5, written.GetProperty("clashes").GetArrayLength());
+        }
+        finally
+        {
+            File.Delete(path);
+        }
+    }
+
     private static NwcClashResult CreateClash(
         string name,
         Vector3d point,