diff --git a/Services/LayoutStore.Snapshots.cs b/Services/LayoutStore.Snapshots.cs
index 3846174..b6042ff 100644
--- a/Services/LayoutStore.Snapshots.cs
+++ b/Services/LayoutStore.Snapshots.cs
@@ -56,10 +56,18 @@ public partial class LayoutStore : IDisposable
     /// <see cref="CaptureDefaultsIfMissing"/> after its factory scenes have been seeded.</summary>
     public void PrepareLayoutSnapshots(string buildId)
     {
-        if (GetSnapshotState(DefaultsInitializedKey) != "1" && HasStoredScenes())
+        ArgumentException.ThrowIfNullOrWhiteSpace(buildId);
+        var defaultsInitialized = GetSnapshotState(DefaultsInitializedKey) == "1";
+        if (!defaultsInitialized && HasStoredScenes())
+        {
             CaptureDefaults();
+            defaultsInitialized = true;
+        }
 
-        if (string.IsNullOrWhiteSpace(GetSnapshotState(CurrentBuildIdKey)))
+        var currentBuildId = GetSnapshotState(CurrentBuildIdKey);
+        if (defaultsInitialized && !string.Equals(currentBuildId, buildId, StringComparison.Ordinal))
+            RestoreDefaults(buildId);
+        else if (!defaultsInitialized && string.IsNullOrWhiteSpace(currentBuildId))
             SetSnapshotState(CurrentBuildIdKey, buildId);
     }
 
@@ -121,6 +129,45 @@ public partial class LayoutStore : IDisposable
         tx.Commit();
     }
 
+    private void RestoreDefaults(string buildId)
+    {
+        var columnsByTable = SnapshotTables.ToDictionary(table => table, ReadColumnNames);
+        using var tx = _connection.BeginTransaction();
+
+        foreach (var table in SnapshotTables.Reverse())
+        {
+            using var delete = _connection.CreateCommand();
+            delete.Transaction = tx;
+            delete.CommandText = $"DELETE FROM {table};";
+            delete.ExecuteNonQuery();
+        }
+
+        foreach (var table in SnapshotTables)
+        {
+            var columns = string.Join(", ", columnsByTable[table].Select(QuoteIdentifier));
+            using var copy = _connection.CreateCommand();
+            copy.Transaction = tx;
+            copy.CommandText = $"INSERT INTO {table} ({columns}) SELECT {columns} FROM Default{table};";
+            copy.ExecuteNonQuery();
+        }
+
+        using (var clearSettings = _connection.CreateCommand())
+        {
+            clearSettings.Transaction = tx;
+            clearSettings.CommandText = "DELETE FROM Settings WHERE Key LIKE 'BackgroundPath_%' OR Key LIKE 'BackgroundUseDefault_%';";
+            clearSettings.ExecuteNonQuery();
+        }
+        using (var copySettings = _connection.CreateCommand())
+        {
+            copySettings.Transaction = tx;
+            copySettings.CommandText = "INSERT INTO Settings (Key, Value) SELECT Key, Value FROM DefaultLayoutSetting;";
+            copySettings.ExecuteNonQuery();
+        }
+
+        SetSnapshotState(CurrentBuildIdKey, buildId, tx);
+        tx.Commit();
+    }
+
     private bool HasStoredScenes()
     {
         using var cmd = _connection.CreateCommand();
@@ -136,9 +183,10 @@ public partial class LayoutStore : IDisposable
         return cmd.ExecuteScalar() as string;
     }
 
-    private void SetSnapshotState(string key, string value)
+    private void SetSnapshotState(string key, string value, SqliteTransaction? transaction = null)
     {
         using var cmd = _connection.CreateCommand();
+        cmd.Transaction = transaction;
         cmd.CommandText = """
             INSERT INTO LayoutSnapshotState (Key, Value) VALUES ($key, $value)
             ON CONFLICT(Key) DO UPDATE SET Value = excluded.Value;
diff --git a/ytLive.Tests/LayoutStoreSnapshotTests.cs b/ytLive.Tests/LayoutStoreSnapshotTests.cs
index dc17c4a..3febf26 100644
--- a/ytLive.Tests/LayoutStoreSnapshotTests.cs
+++ b/ytLive.Tests/LayoutStoreSnapshotTests.cs
@@ -48,6 +48,38 @@ public sealed class LayoutStoreSnapshotTests
         }
     }
 
+    [Fact]
+    public void DifferentBuild_RestoresTheDefaultSnapshotBeforeLoading()
+    {
+        var path = Path.Combine(Path.GetTempPath(), $"ytLlive-layout-snapshot-{Guid.NewGuid():N}.db");
+        try
+        {
+            using (var store = new LayoutStore(path))
+            {
+                store.Save(new[] { MakeScene("Factory title") }, null, null);
+                store.PrepareLayoutSnapshots("build-a");
+                store.Save(new[] { MakeScene("Creator edit") }, null, null);
+            }
+
+            using (var reopened = new LayoutStore(path))
+            {
+                reopened.PrepareLayoutSnapshots("build-b");
+                var restored = Assert.Single(reopened.Load());
+                Assert.Equal("Factory title", Assert.Single(restored.Elements.OfType<Source>()).Name);
+
+                using var connection = GetConnection(path);
+                using var command = connection.CreateCommand();
+                command.CommandText = "SELECT Value FROM LayoutSnapshotState WHERE Key = 'CurrentBuildId';";
+                Assert.Equal("build-b", command.ExecuteScalar());
+            }
+        }
+        finally
+        {
+            SqliteConnection.ClearAllPools();
+            try { File.Delete(path); } catch { /* best-effort cleanup */ }
+        }
+    }
+
     private static Scene MakeScene(string sourceName)
         => new()
         {