diff --git a/eeschema/annotate.cpp b/eeschema/annotate.cpp
index 1481b9bd32..8907567b4c 100644
--- a/eeschema/annotate.cpp
+++ b/eeschema/annotate.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2004-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2004-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -39,7 +39,7 @@
 void SCH_EDIT_FRAME::mapExistingAnnotation( std::map<wxString, wxString>& aMap )
 {
     SCH_REFERENCE_LIST references;
-    Schematic().BuildUnorderedSheetList().GetSymbols( references );
+    Schematic().Hierarchy().GetSymbols( references );
 
     for( size_t i = 0; i < references.GetCount(); i++ )
     {
@@ -61,7 +61,7 @@ void SCH_EDIT_FRAME::DeleteAnnotation( ANNOTATE_SCOPE_T aAnnotateScope, bool aRe
                                        REPORTER& aReporter )
 {
 
-    SCH_SHEET_LIST sheets = Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = Schematic().Hierarchy();
     SCH_SCREEN*    screen = GetScreen();
     SCH_SHEET_PATH currentSheet = GetCurrentSheet();
     SCH_COMMIT     commit( this );
@@ -219,7 +219,7 @@ void SCH_EDIT_FRAME::AnnotateSymbols( SCH_COMMIT* aCommit, ANNOTATE_SCOPE_T  aAn
 
     SCH_REFERENCE_LIST references;
     SCH_SCREENS        screens( Schematic().Root() );
-    SCH_SHEET_LIST     sheets = Schematic().BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST     sheets = Schematic().Hierarchy();
     SCH_SHEET_PATH     currentSheet = GetCurrentSheet();
 
 
@@ -463,7 +463,7 @@ int SCH_EDIT_FRAME::CheckAnnotate( ANNOTATION_ERROR_HANDLER aErrorHandler,
 {
     SCH_REFERENCE_LIST  referenceList;
     constexpr bool      includePowerSymbols = false;
-    SCH_SHEET_LIST      sheets = Schematic().BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST      sheets = Schematic().Hierarchy();
     SCH_SHEET_PATH      currentSheet = GetCurrentSheet();
 
     // Build the list of symbols
diff --git a/eeschema/cross-probing.cpp b/eeschema/cross-probing.cpp
index c68d28c588..ea6b0abafb 100644
--- a/eeschema/cross-probing.cpp
+++ b/eeschema/cross-probing.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2019 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2011 Wayne Stambaugh <stambaughw@gmail.com>
- * Copyright (C) 2004-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2004-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -54,7 +54,7 @@ SCH_ITEM* SCH_EDITOR_CONTROL::FindSymbolAndItem( const wxString* aPath, const wx
     if( !aSearchHierarchy )
         sheetList.push_back( m_frame->GetCurrentSheet() );
     else
-        sheetList = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
+        sheetList = m_frame->Schematic().Hierarchy();
 
     for( SCH_SHEET_PATH& sheet : sheetList )
     {
@@ -620,7 +620,7 @@ findItemsFromSyncSelection( const SCHEMATIC& aSchematic, const std::string aSync
     std::optional<std::pair<wxString, wxString>>               focusPin;
     std::unordered_map<SCH_SHEET_PATH, std::vector<SCH_ITEM*>> focusItemResults;
 
-    const SCH_SHEET_LIST allSheetsList = aSchematic.BuildUnorderedSheetList();
+    const SCH_SHEET_LIST allSheetsList = aSchematic.Hierarchy();
 
     // In orderedSheets, the current sheet comes first.
     std::vector<SCH_SHEET_PATH> orderedSheets;
diff --git a/eeschema/dialogs/dialog_change_symbols.cpp b/eeschema/dialogs/dialog_change_symbols.cpp
index 97d790f0b9..b8c4e7a7ea 100644
--- a/eeschema/dialogs/dialog_change_symbols.cpp
+++ b/eeschema/dialogs/dialog_change_symbols.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2020-2021 CERN
- * Copyright (C) 2021-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2021-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * @author Wayne Stambaugh <stambaughw@gmail.com>
  *
@@ -289,7 +289,7 @@ void DIALOG_CHANGE_SYMBOLS::updateFieldsList()
     std::vector<SCH_FIELD*> libFields;
     std::set<wxString>      fieldNames;
 
-    for( SCH_SHEET_PATH& instance : frame->Schematic().BuildUnorderedSheetList() )
+    for( SCH_SHEET_PATH& instance : frame->Schematic().Hierarchy() )
     {
         SCH_SCREEN* screen = instance.LastScreen();
 
@@ -495,7 +495,7 @@ int DIALOG_CHANGE_SYMBOLS::processMatchingSymbols( SCH_COMMIT* aCommit )
 
     std::map<SCH_SYMBOL*, SYMBOL_CHANGE_INFO> symbols;
 
-    for( SCH_SHEET_PATH& instance : frame->Schematic().BuildSheetListSortedByPageNumbers() )
+    for( SCH_SHEET_PATH& instance : frame->Schematic().Hierarchy() )
     {
         SCH_SCREEN* screen = instance.LastScreen();
 
@@ -796,7 +796,7 @@ wxString DIALOG_CHANGE_SYMBOLS::getSymbolReferences( SCH_SYMBOL& aSymbol,
 
     wxCHECK( parent, msg );
 
-    SCH_SHEET_LIST sheets = parent->Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = parent->Schematic().Hierarchy();
 
     for( const SCH_SYMBOL_INSTANCE& instance : aSymbol.GetInstances() )
     {
diff --git a/eeschema/dialogs/dialog_edit_symbols_libid.cpp b/eeschema/dialogs/dialog_edit_symbols_libid.cpp
index 4265c95384..a2aa3b1f46 100644
--- a/eeschema/dialogs/dialog_edit_symbols_libid.cpp
+++ b/eeschema/dialogs/dialog_edit_symbols_libid.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright 2017 Jean-Pierre Charras, jp.charras@wanadoo.fr
- * Copyright 1992-2022 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright 1992-2022, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -395,9 +395,9 @@ void DIALOG_EDIT_SYMBOLS_LIBID::initDlg()
 
     // build the full list of symbols including symbol having no symbol in loaded libs
     // (orphan symbols)
-    GetParent()->Schematic().BuildUnorderedSheetList().GetSymbols( references,
-                                                                   true /* include power symbols */,
-                                                                   true /* include orphan symbols */ );
+    GetParent()->Schematic().Hierarchy().GetSymbols( references,
+                                                     true /* include power symbols */,
+                                                     true /* include orphan symbols */ );
 
     for( unsigned ii = 0; ii < references.GetCount(); ii++ )
     {
diff --git a/eeschema/dialogs/dialog_field_properties.cpp b/eeschema/dialogs/dialog_field_properties.cpp
index 390181f508..9c77ed783d 100644
--- a/eeschema/dialogs/dialog_field_properties.cpp
+++ b/eeschema/dialogs/dialog_field_properties.cpp
@@ -680,7 +680,7 @@ void DIALOG_FIELD_PROPERTIES::UpdateField( SCH_COMMIT* aCommit, SCH_FIELD* aFiel
             int      unit = symbol->GetUnit();
             LIB_ID   libId = symbol->GetLibId();
 
-            for( SCH_SHEET_PATH& sheet : editFrame->Schematic().BuildUnorderedSheetList() )
+            for( SCH_SHEET_PATH& sheet : editFrame->Schematic().Hierarchy() )
             {
                 SCH_SCREEN*              screen = sheet.LastScreen();
                 std::vector<SCH_SYMBOL*> otherUnits;
diff --git a/eeschema/dialogs/dialog_global_edit_text_and_graphics.cpp b/eeschema/dialogs/dialog_global_edit_text_and_graphics.cpp
index 1e956b1be9..95f0af5e15 100644
--- a/eeschema/dialogs/dialog_global_edit_text_and_graphics.cpp
+++ b/eeschema/dialogs/dialog_global_edit_text_and_graphics.cpp
@@ -583,7 +583,7 @@ bool DIALOG_GLOBAL_EDIT_TEXT_AND_GRAPHICS::TransferDataFromWindow()
     SCH_COMMIT     commit( m_parent );
 
     // Go through sheets
-    for( const SCH_SHEET_PATH& sheetPath : m_parent->Schematic().BuildUnorderedSheetList() )
+    for( const SCH_SHEET_PATH& sheetPath : m_parent->Schematic().Hierarchy() )
     {
         SCH_SCREEN* screen = sheetPath.LastScreen();
 
diff --git a/eeschema/dialogs/dialog_sheet_properties.cpp b/eeschema/dialogs/dialog_sheet_properties.cpp
index d1950fdb17..f3d9ed08ab 100644
--- a/eeschema/dialogs/dialog_sheet_properties.cpp
+++ b/eeschema/dialogs/dialog_sheet_properties.cpp
@@ -437,7 +437,7 @@ bool DIALOG_SHEET_PROPERTIES::onSheetFilenameChanged( const wxString& aNewFilena
     // Sheet file names are relative to the path of the current sheet.  This allows for
     // nesting of schematic files in subfolders.  Screen file names are always absolute.
     SCHEMATIC&     schematic = m_frame->Schematic();
-    SCH_SHEET_LIST fullHierarchy = schematic.GetFullHierarchy();
+    SCH_SHEET_LIST fullHierarchy = schematic.Hierarchy();
     wxFileName     screenFileName( sheetFileName );
     wxFileName     tmp( sheetFileName );
     SCH_SCREEN*    currentScreen = m_frame->GetCurrentSheet().LastScreen();
diff --git a/eeschema/dialogs/dialog_symbol_fields_table.cpp b/eeschema/dialogs/dialog_symbol_fields_table.cpp
index 52373958ab..7cd3fe6824 100644
--- a/eeschema/dialogs/dialog_symbol_fields_table.cpp
+++ b/eeschema/dialogs/dialog_symbol_fields_table.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2017 Oliver Walters
- * Copyright (C) 2017-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2017-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -176,7 +176,7 @@ DIALOG_SYMBOL_FIELDS_TABLE::DIALOG_SYMBOL_FIELDS_TABLE( SCH_EDIT_FRAME* parent )
         m_schSettings( parent->Schematic().Settings() )
 {
     // Get all symbols from the list of schematic sheets
-    m_parent->Schematic().BuildUnorderedSheetList().GetSymbols( m_symbolsList, false );
+    m_parent->Schematic().Hierarchy().GetSymbols( m_symbolsList, false );
 
     m_bRefresh->SetBitmap( KiBitmapBundle( BITMAPS::small_refresh ) );
     m_bRefreshPreview->SetBitmap( KiBitmapBundle( BITMAPS::small_refresh ) );
@@ -2217,7 +2217,7 @@ void DIALOG_SYMBOL_FIELDS_TABLE::OnSchItemsAdded( SCHEMATIC&              aSch,
                                                   std::vector<SCH_ITEM*>& aSchItem )
 {
     SCH_REFERENCE_LIST allRefs;
-    m_parent->Schematic().BuildUnorderedSheetList().GetSymbols( allRefs );
+    m_parent->Schematic().Hierarchy().GetSymbols( allRefs );
 
     for( SCH_ITEM* item : aSchItem )
     {
@@ -2286,7 +2286,7 @@ void DIALOG_SYMBOL_FIELDS_TABLE::OnSchItemsChanged( SCHEMATIC&              aSch
                                                     std::vector<SCH_ITEM*>& aSchItem )
 {
     SCH_REFERENCE_LIST allRefs;
-    m_parent->Schematic().BuildUnorderedSheetList().GetSymbols( allRefs );
+    m_parent->Schematic().Hierarchy().GetSymbols( allRefs );
 
     for( SCH_ITEM* item : aSchItem )
     {
@@ -2383,7 +2383,7 @@ DIALOG_SYMBOL_FIELDS_TABLE::getSymbolReferences( SCH_SYMBOL*         aSymbol,
 
 SCH_REFERENCE_LIST DIALOG_SYMBOL_FIELDS_TABLE::getSheetSymbolReferences( SCH_SHEET& aSheet )
 {
-    SCH_SHEET_LIST     allSheets = m_parent->Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST     allSheets = m_parent->Schematic().Hierarchy();
     SCH_REFERENCE_LIST sheetRefs;
 
     // We need to operate on all instances of the sheet
diff --git a/eeschema/dialogs/dialog_table_properties.cpp b/eeschema/dialogs/dialog_table_properties.cpp
index eee168fafd..ec441bdf2c 100644
--- a/eeschema/dialogs/dialog_table_properties.cpp
+++ b/eeschema/dialogs/dialog_table_properties.cpp
@@ -242,7 +242,7 @@ void DIALOG_TABLE_PROPERTIES::getContextualTextVars( const wxString& aCrossRef,
         SCH_REFERENCE_LIST refs;
         SCH_SYMBOL*        refSymbol = nullptr;
 
-        m_frame->Schematic().BuildUnorderedSheetList().GetSymbols( refs );
+        m_frame->Schematic().Hierarchy().GetSymbols( refs );
 
         for( int jj = 0; jj < (int) refs.GetCount(); jj++ )
         {
diff --git a/eeschema/dialogs/dialog_text_properties.cpp b/eeschema/dialogs/dialog_text_properties.cpp
index bb59903b8e..39afd6b3bd 100644
--- a/eeschema/dialogs/dialog_text_properties.cpp
+++ b/eeschema/dialogs/dialog_text_properties.cpp
@@ -166,7 +166,7 @@ DIALOG_TEXT_PROPERTIES::DIALOG_TEXT_PROPERTIES( SCH_BASE_FRAME* aParent, SCH_ITE
     {
         const SCHEMATIC& schematic = schematicEditor->Schematic();
 
-        for( const SCH_SHEET_PATH& sheet : schematic.BuildSheetListSortedByPageNumbers() )
+        for( const SCH_SHEET_PATH& sheet : schematic.Hierarchy() )
         {
             wxString sheetPageNum = sheet.GetPageNumber();
             wxString sheetName = sheet.size() == 1 ? _( "<root sheet>" )
@@ -230,7 +230,7 @@ void DIALOG_TEXT_PROPERTIES::getContextualTextVars( const wxString& aCrossRef,
         if( schematic )
         {
             SCH_REFERENCE_LIST refs;
-            schematic->BuildUnorderedSheetList().GetSymbols( refs );
+            schematic->Hierarchy().GetSymbols( refs );
 
             for( int jj = 0; jj < (int) refs.GetCount(); jj++ )
             {
diff --git a/eeschema/eeschema.cpp b/eeschema/eeschema.cpp
index 600cad28ec..dfb5103be6 100644
--- a/eeschema/eeschema.cpp
+++ b/eeschema/eeschema.cpp
@@ -94,7 +94,7 @@ static std::unique_ptr<SCHEMATIC> readSchematicFromFile( const std::string& aFil
     for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
         screen->UpdateLocalLibSymbolLinks();
 
-    SCH_SHEET_LIST sheets = schematic->BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheets = schematic->Hierarchy();
 
     // Restore all of the loaded symbol instances from the root sheet screen.
     sheets.UpdateSymbolInstanceData( schematic->RootScreen()->GetSymbolInstances() );
@@ -704,4 +704,4 @@ int IFACE::HandleJob( JOB* aJob )
 bool IFACE::HandleJobConfig( JOB* aJob, wxWindow* aParent )
 {
     return m_jobHandler->HandleJobConfig( aJob, aParent );
-}
\ No newline at end of file
+}
diff --git a/eeschema/eeschema_helpers.cpp b/eeschema/eeschema_helpers.cpp
index 887b3111ab..ebe2b5d560 100644
--- a/eeschema/eeschema_helpers.cpp
+++ b/eeschema/eeschema_helpers.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2022 KiCad Developers, see AUTHORS.TXT for contributors.
+ * Copyright (C) 2022, 2024 KiCad Developers, see AUTHORS.TXT for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
diff --git a/eeschema/eeschema_jobs_handler.cpp b/eeschema/eeschema_jobs_handler.cpp
index b2364ae172..fdef58e01e 100644
--- a/eeschema/eeschema_jobs_handler.cpp
+++ b/eeschema/eeschema_jobs_handler.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2022 Mark Roszko <mark.roszko@gmail.com>
- * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software: you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -348,7 +348,7 @@ int EESCHEMA_JOBS_HANDLER::JobExportNetlist( JOB* aJob )
 
     // Annotation warning check
     SCH_REFERENCE_LIST referenceList;
-    sch->BuildUnorderedSheetList().GetSymbols( referenceList );
+    sch->Hierarchy().GetSymbols( referenceList );
 
     if( referenceList.GetCount() > 0 )
     {
@@ -458,7 +458,7 @@ int EESCHEMA_JOBS_HANDLER::JobExportBom( JOB* aJob )
 
     // Annotation warning check
     SCH_REFERENCE_LIST referenceList;
-    sch->BuildUnorderedSheetList().GetSymbols( referenceList, false, false );
+    sch->Hierarchy().GetSymbols( referenceList, false, false );
 
     if( referenceList.GetCount() > 0 )
     {
@@ -711,7 +711,7 @@ int EESCHEMA_JOBS_HANDLER::JobExportPythonBom( JOB* aJob )
 
     // Annotation warning check
     SCH_REFERENCE_LIST referenceList;
-    sch->BuildUnorderedSheetList().GetSymbols( referenceList );
+    sch->Hierarchy().GetSymbols( referenceList );
 
     if( referenceList.GetCount() > 0 )
     {
diff --git a/eeschema/erc/erc_report.cpp b/eeschema/erc/erc_report.cpp
index ab7a36ea61..61427feeb4 100644
--- a/eeschema/erc/erc_report.cpp
+++ b/eeschema/erc/erc_report.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software: you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -121,7 +121,7 @@ bool ERC_REPORT::WriteJsonReport( const wxString& aFullFileName )
     reportHead.kicad_version = GetMajorMinorPatchVersion();
     reportHead.coordinate_units = EDA_UNIT_UTILS::GetLabel( m_reportUnits );
 
-    SCH_SHEET_LIST sheetList = m_sch->BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheetList = m_sch->Hierarchy();
     sheetList.FillItemMap( itemMap );
 
     ERC_SETTINGS& settings = m_sch->ErcSettings();
@@ -156,4 +156,4 @@ bool ERC_REPORT::WriteJsonReport( const wxString& aFullFileName )
     jsonFileStream.close();
 
     return true;
-}
\ No newline at end of file
+}
diff --git a/eeschema/files-io.cpp b/eeschema/files-io.cpp
index a7102888ae..bd1466c662 100644
--- a/eeschema/files-io.cpp
+++ b/eeschema/files-io.cpp
@@ -334,7 +334,7 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
 
         // It's possible the schematic parser fixed errors due to bugs so warn the user
         // that the schematic has been fixed (modified).
-        SCH_SHEET_LIST sheetList = Schematic().BuildSheetListSortedByPageNumbers();
+        SCH_SHEET_LIST sheetList = Schematic().Hierarchy();
 
         if( sheetList.IsModified() )
         {
@@ -1022,7 +1022,7 @@ bool SCH_EDIT_FRAME::SaveProject( bool aSaveAs )
         }
 
         // Attempt to make sheet file name paths relative to the new root schematic path.
-        for( SCH_SHEET_PATH& sheet : Schematic().BuildUnorderedSheetList() )
+        for( SCH_SHEET_PATH& sheet : Schematic().Hierarchy() )
         {
             if( !sheet.Last()->IsRootSheet() )
                 sheet.MakeFilePathRelativeToParentSheet();
@@ -1185,7 +1185,7 @@ bool SCH_EDIT_FRAME::SaveProject( bool aSaveAs )
     std::vector<FILE_INFO_PAIR>& sheets = Prj().GetProjectFile().GetSheets();
     sheets.clear();
 
-    for( SCH_SHEET_PATH& sheetPath : Schematic().BuildUnorderedSheetList() )
+    for( SCH_SHEET_PATH& sheetPath : Schematic().Hierarchy() )
     {
         SCH_SHEET* sheet = sheetPath.Last();
 
diff --git a/eeschema/net_navigator.cpp b/eeschema/net_navigator.cpp
index 0453629781..f5205436c2 100644
--- a/eeschema/net_navigator.cpp
+++ b/eeschema/net_navigator.cpp
@@ -260,7 +260,7 @@ void SCH_EDIT_FRAME::RefreshNetNavigator( const NET_NAVIGATOR_ITEM_DATA* aSelect
     if( !m_netNavigator->IsShown() )
         return;
 
-    bool   singleSheetSchematic = m_schematic->BuildUnorderedSheetList().size() == 1;
+    bool   singleSheetSchematic = m_schematic->Hierarchy().size() == 1;
     size_t nodeCnt = 0;
 
     m_netNavigator->Freeze();
diff --git a/eeschema/netlist_exporters/netlist_exporter_allegro.cpp b/eeschema/netlist_exporters/netlist_exporter_allegro.cpp
index 7d827cee28..0f4d89fec1 100644
--- a/eeschema/netlist_exporters/netlist_exporter_allegro.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_allegro.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -136,7 +136,7 @@ void NETLIST_EXPORTER_ALLEGRO::extractComponentsInfo()
     m_referencesAlreadyFound.Clear();
     m_libParts.clear();
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->Hierarchy() )
     {
         m_schematic->SetCurrentSheet( sheet );
 
diff --git a/eeschema/netlist_exporters/netlist_exporter_base.cpp b/eeschema/netlist_exporters/netlist_exporter_base.cpp
index d9b069547d..ade6c1e85f 100644
--- a/eeschema/netlist_exporters/netlist_exporter_base.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_base.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 1992-2017 jp.charras at wanadoo.fr
  * Copyright (C) 2013-2017 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
- * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -241,7 +241,7 @@ void NETLIST_EXPORTER_BASE::findAllUnitsOfSymbol( SCH_SYMBOL* aSchSymbol,
 
     CONNECTION_GRAPH* graph = m_schematic->ConnectionGraph();
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->Hierarchy() )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
diff --git a/eeschema/netlist_exporters/netlist_exporter_cadstar.cpp b/eeschema/netlist_exporters/netlist_exporter_cadstar.cpp
index 1e207bda38..12520e98a1 100644
--- a/eeschema/netlist_exporters/netlist_exporter_cadstar.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_cadstar.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 1992-2018 jp.charras at wanadoo.fr
  * Copyright (C) 2013 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
- * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -65,7 +65,7 @@ bool NETLIST_EXPORTER_CADSTAR::WriteNetlist( const wxString& aOutFileName,
     // Create netlist footprints section
     m_referencesAlreadyFound.Clear();
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->Hierarchy() )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
diff --git a/eeschema/netlist_exporters/netlist_exporter_orcadpcb2.cpp b/eeschema/netlist_exporters/netlist_exporter_orcadpcb2.cpp
index 8a3fc9e3ee..44daad4481 100644
--- a/eeschema/netlist_exporters/netlist_exporter_orcadpcb2.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_orcadpcb2.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 1992-2018 jp.charras at wanadoo.fr
  * Copyright (C) 2013 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
- * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -62,7 +62,7 @@ bool NETLIST_EXPORTER_ORCADPCB2::WriteNetlist( const wxString& aOutFileName,
     // Create netlist footprints section
     m_referencesAlreadyFound.Clear();
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->Hierarchy() )
     {
         // Process symbol attributes
         for( EDA_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
diff --git a/eeschema/netlist_exporters/netlist_exporter_pads.cpp b/eeschema/netlist_exporters/netlist_exporter_pads.cpp
index 98d4653de7..ed9d5e81c1 100644
--- a/eeschema/netlist_exporters/netlist_exporter_pads.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_pads.cpp
@@ -55,7 +55,7 @@ bool NETLIST_EXPORTER_PADS::WriteNetlist( const wxString& aOutFileName,
     // Create netlist footprints section
     m_referencesAlreadyFound.Clear();
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->Hierarchy() )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
diff --git a/eeschema/netlist_exporters/netlist_exporter_spice.cpp b/eeschema/netlist_exporters/netlist_exporter_spice.cpp
index b6dd752abc..34c98c8172 100644
--- a/eeschema/netlist_exporters/netlist_exporter_spice.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_spice.cpp
@@ -706,7 +706,7 @@ SCH_SHEET_LIST NETLIST_EXPORTER_SPICE::BuildSheetList( unsigned aNetlistOptions
     if( aNetlistOptions & OPTION_CUR_SHEET_AS_ROOT )
         sheets = SCH_SHEET_LIST( m_schematic->CurrentSheet().Last() );
     else
-        sheets = m_schematic->BuildSheetListSortedByPageNumbers();
+        sheets = m_schematic->Hierarchy();
 
     alg::delete_if( sheets,
                     [&]( const SCH_SHEET_PATH& sheet )
diff --git a/eeschema/netlist_exporters/netlist_exporter_xml.cpp b/eeschema/netlist_exporters/netlist_exporter_xml.cpp
index 123fff4af4..4e780b3ea1 100644
--- a/eeschema/netlist_exporters/netlist_exporter_xml.cpp
+++ b/eeschema/netlist_exporters/netlist_exporter_xml.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 1992-2013 jp.charras at wanadoo.fr
  * Copyright (C) 2013-2017 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
- * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -247,7 +247,7 @@ XNODE* NETLIST_EXPORTER_XML::makeSymbols( unsigned aCtl )
     m_libParts.clear();
 
     SCH_SHEET_PATH currentSheet = m_schematic->CurrentSheet();
-    SCH_SHEET_LIST sheetList = m_schematic->BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheetList = m_schematic->Hierarchy();
 
     // Output is xml, so there is no reason to remove spaces from the field values.
     // And XML element names need not be translated to various languages.
@@ -535,7 +535,7 @@ XNODE* NETLIST_EXPORTER_XML::makeDesignHeader()
      */
     unsigned sheetIndex = 1;     // Human readable index
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->Hierarchy() )
     {
         screen = sheet.LastScreen();
 
diff --git a/eeschema/netlist_exporters/netlist_generator.cpp b/eeschema/netlist_exporters/netlist_generator.cpp
index 3595ba7525..a339cc6e28 100644
--- a/eeschema/netlist_exporters/netlist_generator.cpp
+++ b/eeschema/netlist_exporters/netlist_generator.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 1992-2018 jp.charras at wanadoo.fr
  * Copyright (C) 2013 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
- * Copyright (C) 1992-2021 KiCad Developers, see change_log.txt for contributors.
+ * Copyright (C) 1992-2021, 2024 KiCad Developers, see change_log.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -51,7 +51,7 @@ bool SCH_EDIT_FRAME::WriteNetListFile( int aFormat, const wxString& aFullFileNam
                                        unsigned aNetlistOptions, REPORTER* aReporter )
 {
     // Ensure all power symbols have a valid reference
-    Schematic().BuildSheetListSortedByPageNumbers().AnnotatePowerSymbols();
+    Schematic().Hierarchy().AnnotatePowerSymbols();
 
     if( !ReadyToNetlist( _( "Exporting netlist requires a fully annotated schematic." ) ) )
         return false;
@@ -193,7 +193,7 @@ bool SCH_EDIT_FRAME::WriteNetListFile( int aFormat, const wxString& aFullFileNam
 bool SCH_EDIT_FRAME::ReadyToNetlist( const wxString& aAnnotateMessage )
 {
     // Ensure all power symbols have a valid reference
-    Schematic().BuildSheetListSortedByPageNumbers().AnnotatePowerSymbols();
+    Schematic().Hierarchy().AnnotatePowerSymbols();
 
     // Symbols must be annotated
     if( CheckAnnotate( []( ERCE_T, const wxString&, SCH_REFERENCE*, SCH_REFERENCE* ) {} ) )
diff --git a/eeschema/printing/sch_printout.cpp b/eeschema/printing/sch_printout.cpp
index 8df1eb2be1..20cff5d39b 100644
--- a/eeschema/printing/sch_printout.cpp
+++ b/eeschema/printing/sch_printout.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2023 Jean-Pierre Charras, jp.charras at wanadoo.fr
- * Copyright (C) 2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software: you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -71,7 +71,7 @@ bool SCH_PRINTOUT::OnBeginDocument( int startPage, int endPage )
 
 bool SCH_PRINTOUT::OnPrintPage( int page )
 {
-    SCH_SHEET_LIST sheetList = m_parent->Schematic().BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheetList = m_parent->Schematic().Hierarchy();
     sheetList.SortByPageNumbers( false );
 
     wxCHECK_MSG( page >= 1 && page <= (int)sheetList.size(), false,
diff --git a/eeschema/sch_commit.cpp b/eeschema/sch_commit.cpp
index 2b1ed2e7c3..24ce13c8bd 100644
--- a/eeschema/sch_commit.cpp
+++ b/eeschema/sch_commit.cpp
@@ -383,8 +383,13 @@ void SCH_COMMIT::pushSchEdit( const wxString& aMessage, int aCommitFlags )
         if( itemsChanged.size() > 0 )
             schematic->OnItemsChanged( itemsChanged );
 
-        if( frame && refreshHierarchy )
-            frame->UpdateHierarchyNavigator();
+        if( refreshHierarchy )
+        {
+            schematic->RefreshHierarchy();
+
+            if( frame )
+                frame->UpdateHierarchyNavigator();
+        }
     }
 
     if( !( aCommitFlags & SKIP_UNDO ) )
@@ -588,7 +593,7 @@ void SCH_COMMIT::Revert()
                 {
                     // Lazy eval of sheet list; this is expensive even when unsorted
                     if( sheets.empty() )
-                        sheets = schematic->BuildUnorderedSheetList();
+                        sheets = schematic->Hierarchy();
 
                     SCH_SHEET_PATH sheet = sheets.FindSheetForScreen( screen );
                     symbol->SetRef( &sheet, field->GetText() );
diff --git a/eeschema/sch_edit_frame.cpp b/eeschema/sch_edit_frame.cpp
index d4b87c90b8..80d8475ce6 100644
--- a/eeschema/sch_edit_frame.cpp
+++ b/eeschema/sch_edit_frame.cpp
@@ -1050,7 +1050,7 @@ bool SCH_EDIT_FRAME::canCloseWindow( wxCloseEvent& aEvent )
 
 void SCH_EDIT_FRAME::doCloseWindow()
 {
-    SCH_SHEET_LIST sheetlist = Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheetlist = Schematic().Hierarchy();
 
     // Shutdown all running tools
     if( m_toolManager )
@@ -1763,7 +1763,7 @@ void SCH_EDIT_FRAME::RecalculateConnections( SCH_COMMIT* aCommit, SCH_CLEANUP_FL
     wxString            highlightedConn = GetHighlightedConnection();
     bool                hasHighlightedConn = !highlightedConn.IsEmpty();
     SCHEMATIC_SETTINGS& settings = Schematic().Settings();
-    SCH_SHEET_LIST      list = Schematic().BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST      list = Schematic().Hierarchy();
     SCH_COMMIT          localCommit( m_toolManager );
 
     if( !aCommit )
@@ -2275,7 +2275,7 @@ const BOX2I SCH_EDIT_FRAME::GetDocumentExtents( bool aIncludeAllVisible ) const
 
 bool SCH_EDIT_FRAME::IsContentModified() const
 {
-    return Schematic().BuildUnorderedSheetList().IsModified();
+    return Schematic().Hierarchy().IsModified();
 }
 
 
@@ -2347,7 +2347,7 @@ void SCH_EDIT_FRAME::SaveSymbolToSchematic( const LIB_SYMBOL& aSymbol,
                                             const KIID& aSchematicSymbolUUID )
 {
     SCH_SHEET_PATH principalPath;
-    SCH_SHEET_LIST sheets = Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = Schematic().Hierarchy();
     SCH_ITEM*      item = sheets.GetItem( aSchematicSymbolUUID, &principalPath );
     SCH_SYMBOL*    principalSymbol = dynamic_cast<SCH_SYMBOL*>( item );
     SCH_COMMIT     commit( m_toolManager );
diff --git a/eeschema/sch_field.cpp b/eeschema/sch_field.cpp
index 2e70954937..6746488d20 100644
--- a/eeschema/sch_field.cpp
+++ b/eeschema/sch_field.cpp
@@ -875,7 +875,7 @@ void SCH_FIELD::OnScintillaCharAdded( SCINTILLA_TRICKS* aScintillaTricks,
                 SCH_REFERENCE_LIST refs;
                 SCH_SYMBOL*        refSymbol = nullptr;
 
-                schematic->BuildUnorderedSheetList().GetSymbols( refs );
+                schematic->Hierarchy().GetSymbols( refs );
 
                 for( size_t jj = 0; jj < refs.GetCount(); jj++ )
                 {
@@ -1776,4 +1776,4 @@ static struct SCH_FIELD_DESC
 
 
 DECLARE_ENUM_TO_WXANY( GR_TEXT_H_ALIGN_T )
-DECLARE_ENUM_TO_WXANY( GR_TEXT_V_ALIGN_T )
\ No newline at end of file
+DECLARE_ENUM_TO_WXANY( GR_TEXT_V_ALIGN_T )
diff --git a/eeschema/sch_io/cadstar/sch_io_cadstar_archive.cpp b/eeschema/sch_io/cadstar/sch_io_cadstar_archive.cpp
index a7c8c469ef..17b2e59c55 100644
--- a/eeschema/sch_io/cadstar/sch_io_cadstar_archive.cpp
+++ b/eeschema/sch_io/cadstar/sch_io_cadstar_archive.cpp
@@ -145,7 +145,7 @@ SCH_SHEET* SCH_IO_CADSTAR_ARCHIVE::LoadSchematicFile( const wxString&        aFi
     sch_plugin->SaveLibrary( libFileName.GetFullPath() );
 
     // Link up all symbols in the design to the newly created library
-    for( SCH_SHEET_PATH& sheet : aSchematic->BuildUnorderedSheetList() )
+    for( SCH_SHEET_PATH& sheet : aSchematic->Hierarchy() )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
diff --git a/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp b/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp
index b40756ff63..7a1cea44ec 100644
--- a/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp
+++ b/eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp
@@ -368,7 +368,7 @@ void SCH_IO_KICAD_SEXPR::Format( SCH_SHEET* aSheet )
     wxCHECK_RET( aSheet != nullptr, "NULL SCH_SHEET* object." );
     wxCHECK_RET( m_schematic != nullptr, "NULL SCHEMATIC* object." );
 
-    SCH_SHEET_LIST sheets = m_schematic->BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheets = m_schematic->Hierarchy();
     SCH_SCREEN* screen = aSheet->GetScreen();
 
     wxCHECK( screen, /* void */ );
@@ -538,7 +538,7 @@ void SCH_IO_KICAD_SEXPR::Format( EE_SELECTION* aSelection, SCH_SHEET_PATH* aSele
     wxCHECK( aSelection && aSelectionPath && aFormatter, /* void */ );
 
     LOCALE_IO toggle;
-    SCH_SHEET_LIST sheets = aSchematic.BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheets = aSchematic.Hierarchy();
 
     m_schematic = &aSchematic;
     m_out = aFormatter;
diff --git a/eeschema/sch_screen.cpp b/eeschema/sch_screen.cpp
index 96d388b8d2..afb6e4001f 100644
--- a/eeschema/sch_screen.cpp
+++ b/eeschema/sch_screen.cpp
@@ -1696,7 +1696,7 @@ void SCH_SCREENS::ClearAnnotationOfNewSheetPaths( SCH_SHEET_LIST& aInitialSheetP
 
     // Search for new sheet paths, not existing in aInitialSheetPathList
     // and existing in sheetpathList
-    for( SCH_SHEET_PATH& sheetpath : sch->BuildSheetListSortedByPageNumbers() )
+    for( SCH_SHEET_PATH& sheetpath : sch->Hierarchy() )
     {
         bool path_exists = false;
 
@@ -1836,7 +1836,7 @@ void SCH_SCREENS::UpdateSymbolLinks( REPORTER* aReporter )
 
     wxCHECK_RET( sch, "Null schematic in SCH_SCREENS::UpdateSymbolLinks" );
 
-    SCH_SHEET_LIST sheets = sch->BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheets = sch->Hierarchy();
 
     // All of the library symbols have been replaced with copies so the connection graph
     // pointers are stale.
@@ -1935,7 +1935,7 @@ void SCH_SCREENS::BuildClientSheetPathList()
     for( SCH_SCREEN* curr_screen = GetFirst(); curr_screen; curr_screen = GetNext() )
         curr_screen->GetClientSheetPaths().clear();
 
-    for( SCH_SHEET_PATH& sheetpath : sch->BuildSheetListSortedByPageNumbers() )
+    for( SCH_SHEET_PATH& sheetpath : sch->Hierarchy() )
     {
         SCH_SCREEN* used_screen = sheetpath.LastScreen();
 
diff --git a/eeschema/sch_sheet.cpp b/eeschema/sch_sheet.cpp
index af1865cdc2..904f068b91 100644
--- a/eeschema/sch_sheet.cpp
+++ b/eeschema/sch_sheet.cpp
@@ -297,7 +297,7 @@ bool SCH_SHEET::ResolveTextVar( const SCH_SHEET_PATH* aPath, wxString* token, in
     }
     else if( token->IsSameAs( wxT( "##" ) ) )
     {
-        *token = wxString::Format( wxT( "%d" ), (int) schematic->BuildUnorderedSheetList().size() );
+        *token = wxString::Format( wxT( "%d" ), (int) schematic->Hierarchy().size() );
         return true;
     }
     else if( token->IsSameAs( wxT( "SHEETPATH" ) ) )
diff --git a/eeschema/sch_symbol.cpp b/eeschema/sch_symbol.cpp
index 88268f0be2..1c2ef40eb5 100644
--- a/eeschema/sch_symbol.cpp
+++ b/eeschema/sch_symbol.cpp
@@ -1142,7 +1142,7 @@ void SCH_SYMBOL::SyncOtherUnits( const SCH_SHEET_PATH& aSourceSheet, SCH_COMMIT&
     {
         wxString ref = GetRef( &aSourceSheet );
 
-        for( SCH_SHEET_PATH& sheet : Schematic()->BuildUnorderedSheetList() )
+        for( SCH_SHEET_PATH& sheet : Schematic()->Hierarchy() )
         {
             SCH_SCREEN*              screen = sheet.LastScreen();
             std::vector<SCH_SYMBOL*> otherUnits;
diff --git a/eeschema/schematic.cpp b/eeschema/schematic.cpp
index a29cd1b1cb..be84355169 100644
--- a/eeschema/schematic.cpp
+++ b/eeschema/schematic.cpp
@@ -78,7 +78,7 @@ SCHEMATIC::SCHEMATIC( PROJECT* aPrj ) :
                 int      unit = symbol->GetUnit();
                 LIB_ID   libId = symbol->GetLibId();
 
-                for( SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
+                for( SCH_SHEET_PATH& sheet : Hierarchy() )
                 {
                     std::vector<SCH_SYMBOL*> otherUnits;
 
@@ -200,6 +200,7 @@ void SCHEMATIC::SetRoot( SCH_SHEET* aRootSheet )
     m_currentSheet->clear();
     m_currentSheet->push_back( m_rootSheet );
 
+    m_hierarchy = BuildSheetListSortedByPageNumbers();
     m_connectionGraph->Reset();
 }
 
@@ -210,6 +211,22 @@ SCH_SCREEN* SCHEMATIC::RootScreen() const
 }
 
 
+SCH_SHEET_LIST SCHEMATIC::Hierarchy() const
+{
+    wxCHECK( !m_hierarchy.empty(), m_hierarchy );
+
+    return m_hierarchy;
+}
+
+
+void SCHEMATIC::RefreshHierarchy()
+{
+    wxLogDebug( wxS( "Refreshing schematic heirarchy." ) );
+
+    m_hierarchy = SCH_SHEET_LIST( m_rootSheet );
+}
+
+
 void SCHEMATIC::GetContextualTextVars( wxArrayString* aVars ) const
 {
     auto add =
@@ -310,7 +327,7 @@ ERC_SETTINGS& SCHEMATIC::ErcSettings() const
 
 std::vector<SCH_MARKER*> SCHEMATIC::ResolveERCExclusions()
 {
-    SCH_SHEET_LIST sheetList = BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheetList = Hierarchy();
     ERC_SETTINGS&  settings  = ErcSettings();
 
     // Migrate legacy marker exclusions to new format to ensure exclusion matching functions across
@@ -392,7 +409,7 @@ std::vector<SCH_MARKER*> SCHEMATIC::ResolveERCExclusions()
 
 std::shared_ptr<BUS_ALIAS> SCHEMATIC::GetBusAlias( const wxString& aLabel ) const
 {
-    for( const SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
+    for( const SCH_SHEET_PATH& sheet : Hierarchy() )
     {
         for( const std::shared_ptr<BUS_ALIAS>& alias : sheet.LastScreen()->GetBusAliases() )
         {
@@ -462,7 +479,7 @@ std::map<int, wxString> SCHEMATIC::GetVirtualPageToSheetNamesMap() const
 {
     std::map<int, wxString> namesMap;
 
-    for( const SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
+    for( const SCH_SHEET_PATH& sheet : Hierarchy() )
     {
         if( sheet.size() == 1 )
             namesMap[sheet.GetVirtualPageNumber()] = _( "<root sheet>" );
@@ -478,7 +495,7 @@ std::map<int, wxString> SCHEMATIC::GetVirtualPageToSheetPagesMap() const
 {
     std::map<int, wxString> pagesMap;
 
-    for( const SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
+    for( const SCH_SHEET_PATH& sheet : Hierarchy() )
         pagesMap[sheet.GetVirtualPageNumber()] = sheet.GetPageNumber();
 
     return pagesMap;
@@ -526,7 +543,7 @@ wxString SCHEMATIC::ConvertRefsToKIIDs( const wxString& aSource ) const
                 wxString           ref = token.BeforeFirst( ':', &remainder );
                 SCH_REFERENCE_LIST references;
 
-                BuildUnorderedSheetList().GetSymbols( references );
+                Hierarchy().GetSymbols( references );
 
                 for( size_t jj = 0; jj < references.GetCount(); jj++ )
                 {
@@ -602,17 +619,6 @@ wxString SCHEMATIC::ConvertKIIDsToRefs( const wxString& aSource ) const
 }
 
 
-SCH_SHEET_LIST& SCHEMATIC::GetFullHierarchy() const
-{
-    static SCH_SHEET_LIST hierarchy;
-
-    hierarchy.clear();
-    hierarchy.BuildSheetList( m_rootSheet, false );
-
-    return hierarchy;
-}
-
-
 void SCHEMATIC::SetLegacySymbolInstanceData()
 {
     SCH_SCREENS screens( m_rootSheet );
@@ -649,7 +655,7 @@ void SCHEMATIC::SetSheetNumberAndCount()
 
     // @todo Remove all pseudo page number system is left over from prior to real page number
     //       implementation.
-    for( const SCH_SHEET_PATH& sheet : BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : Hierarchy() )
     {
         if( sheet.Path() == current_sheetpath ) // Current sheet path found
             break;
@@ -672,7 +678,7 @@ void SCHEMATIC::RecomputeIntersheetRefs( const std::function<void( SCH_GLOBALLAB
 
     pageRefsMap.clear();
 
-    for( const SCH_SHEET_PATH& sheet : BuildSheetListSortedByPageNumbers() )
+    for( const SCH_SHEET_PATH& sheet : Hierarchy() )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_GLOBAL_LABEL_T ) )
         {
@@ -811,7 +817,7 @@ void SCHEMATIC::RemoveAllListeners()
 void SCHEMATIC::RecordERCExclusions()
 {
     // Use a sorted sheetList to reduce file churn
-    SCH_SHEET_LIST sheetList = BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST sheetList = Hierarchy();
     ERC_SETTINGS&  ercSettings = ErcSettings();
 
     ercSettings.m_ErcExclusions.clear();
@@ -836,7 +842,7 @@ void SCHEMATIC::RecordERCExclusions()
 
 void SCHEMATIC::ResolveERCExclusionsPostUpdate()
 {
-    SCH_SHEET_LIST sheetList = BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheetList = Hierarchy();
 
     for( SCH_MARKER* marker : ResolveERCExclusions() )
     {
@@ -867,7 +873,7 @@ void SCHEMATIC::EmbedFonts()
 {
     std::set<KIFONT::OUTLINE_FONT*> fonts;
 
-    SCH_SHEET_LIST sheetList = BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheetList = Hierarchy();
 
     for( const SCH_SHEET_PATH& sheet : sheetList )
     {
diff --git a/eeschema/schematic.h b/eeschema/schematic.h
index 529799e9c7..31a7b7bf96 100644
--- a/eeschema/schematic.h
+++ b/eeschema/schematic.h
@@ -49,6 +49,7 @@ public:
     virtual SCH_SHEET_PATH& CurrentSheet() const = 0;
     virtual wxString GetFileName() const = 0;
     virtual PROJECT& Prj() const = 0;
+    virtual SCH_SHEET_LIST Hierarchy() const = 0;
 };
 
 class SCHEMATIC;
@@ -105,6 +106,13 @@ public:
         return sheets;
     }
 
+    /**
+     * Return the full schematic flattened hierarchical sheet list.
+     */
+    SCH_SHEET_LIST Hierarchy() const override;
+
+    void RefreshHierarchy();
+
     SCH_ITEM* GetItem( const KIID& aID, SCH_SHEET_PATH* aPathOut = nullptr ) const
     {
         return BuildUnorderedSheetList().GetItem( aID, aPathOut );
@@ -193,11 +201,6 @@ public:
     wxString ConvertRefsToKIIDs( const wxString& aSource ) const;
     wxString ConvertKIIDsToRefs( const wxString& aSource ) const;
 
-    /**
-     * Return the full schematic flattened hierarchical sheet list.
-     */
-    SCH_SHEET_LIST& GetFullHierarchy() const;
-
     /**
      * Update the symbol value and footprint instance data for legacy designs.
      *
@@ -380,6 +383,11 @@ private:
      */
     std::map<wxString, double>        m_operatingPoints;
 
+    /**
+     * Cache of the entire schematic hierarchy sorted by sheet page number.
+     */
+    SCH_SHEET_LIST m_hierarchy;
+
     /**
      * Currently installed listeners
      */
diff --git a/eeschema/schematic_undo_redo.cpp b/eeschema/schematic_undo_redo.cpp
index 400a0cd305..4cbce3b1ac 100644
--- a/eeschema/schematic_undo_redo.cpp
+++ b/eeschema/schematic_undo_redo.cpp
@@ -285,6 +285,7 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
     std::set<SCH_TABLE*>   changedTables;
     bool                   dirtyConnectivity = false;
     bool                   rebuildHierarchyNavigator = false;
+    bool                   refreshHierarchy = false;
     SCH_CLEANUP_FLAGS      connectivityCleanUp = NO_CLEANUP;
     SCH_SHEET_LIST         sheets;
     bool                   clearedRepeatItems = false;
@@ -357,6 +358,7 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
             if( eda_item->Type() == SCH_SHEET_T )
             {
                 rebuildHierarchyNavigator = true;
+                refreshHierarchy = true;
 
                 if( static_cast<SCH_SHEET*>( eda_item )->GetScreen() == GetScreen() )
                     GetToolManager()->PostAction( EE_ACTIONS::leaveSheet );
@@ -370,7 +372,10 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
         else if( status == UNDO_REDO::DELETED )
         {
             if( eda_item->Type() == SCH_SHEET_T )
+            {
                 rebuildHierarchyNavigator = true;
+                refreshHierarchy = true;
+            }
 
             if( schItem )
                 updateConnectivityFlag();
@@ -385,7 +390,7 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
         {
             // Lazy eval of sheet list; this is expensive even when unsorted
             if( sheets.empty() )
-                sheets = m_schematic->BuildUnorderedSheetList();
+                sheets = m_schematic->Hierarchy();
 
             SCH_SHEET_PATH undoSheet = sheets.FindSheetForScreen( screen );
 
@@ -415,7 +420,10 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
                 AddCopyForRepeatItem( schItem );
 
                 if( schItem->Type() == SCH_SHEET_T )
+                {
                     rebuildHierarchyNavigator = true;
+                    refreshHierarchy = true;
+                }
             }
         }
         else if( schItem )
@@ -448,6 +456,13 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
                     {
                         rebuildHierarchyNavigator = true;
                     }
+
+                    // Sheet name changes do not require rebuilding the hiearchy.
+                    if( ( origSheet->GetFileName() != copySheet->GetFileName() )
+                      || origSheet->HasPageNumberChanges( *copySheet ) )
+                    {
+                        refreshHierarchy = true;
+                    }
                 }
 
                 schItem->SwapData( itemCopy );
@@ -464,7 +479,7 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
                     {
                         // Lazy eval of sheet list; this is expensive even when unsorted
                         if( sheets.empty() )
-                            sheets = m_schematic->BuildUnorderedSheetList();
+                            sheets = m_schematic->Hierarchy();
 
                         SCH_SHEET_PATH sheet = sheets.FindSheetForScreen( screen );
                         symbol->SetRef( &sheet, field->GetText() );
@@ -504,6 +519,9 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
     if( bulkChangedItems.size() > 0 )
         Schematic().OnItemsChanged( bulkChangedItems );
 
+    if( refreshHierarchy )
+        Schematic().RefreshHierarchy();
+
     if( dirtyConnectivity )
     {
         wxLogTrace( wxS( "CONN_PROFILE" ),
diff --git a/eeschema/sheet.cpp b/eeschema/sheet.cpp
index 3caf1a9a90..01256f004f 100644
--- a/eeschema/sheet.cpp
+++ b/eeschema/sheet.cpp
@@ -53,7 +53,7 @@ bool SCH_EDIT_FRAME::CheckSheetForRecursion( SCH_SHEET* aSheet, SCH_SHEET_PATH*
     wxASSERT( aSheet && aCurrentSheet );
 
     wxString msg;
-    SCH_SHEET_LIST schematicSheets = Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST schematicSheets = Schematic().Hierarchy();
     SCH_SHEET_LIST loadedSheets( aSheet );  // This is the schematicSheets of the loaded file.
 
     wxString destFilePath = aCurrentSheet->LastScreen()->GetFileName();
@@ -282,7 +282,7 @@ bool SCH_EDIT_FRAME::LoadSheetFromFile( SCH_SHEET* aSheet, SCH_SHEET_PATH* aCurr
     }
 
     SCH_SHEET_LIST loadedSheets( tmpSheet.get() );
-    SCH_SHEET_LIST schematicSheets = Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST schematicSheets = Schematic().Hierarchy();
 
     // Make sure any new sheet changes do not cause any recursion issues.
     if( !aSkipRecursionCheck && CheckSheetForRecursion( tmpSheet.get(), aCurrentSheet ) )
@@ -699,7 +699,7 @@ void SCH_EDIT_FRAME::DrawCurrentSheetToClipboard()
 bool SCH_EDIT_FRAME::AllowCaseSensitiveFileNameClashes( const wxString& aOldName, const wxString& aSchematicFileName )
 {
     wxString       msg;
-    SCH_SHEET_LIST sheets = Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = Schematic().Hierarchy();
     wxFileName     fn = aSchematicFileName;
 
     wxCHECK( fn.IsAbsolute(), false );
diff --git a/eeschema/tools/assign_footprints.cpp b/eeschema/tools/assign_footprints.cpp
index b5669b4ae8..e8e43fd2d3 100644
--- a/eeschema/tools/assign_footprints.cpp
+++ b/eeschema/tools/assign_footprints.cpp
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2015 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2008 Wayne Stambaugh <stambaughw@gmail.com>
- * Copyright (C) 2004-2022 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2004-2022, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -48,7 +48,7 @@ void SCH_EDITOR_CONTROL::AssignFootprints( const std::string& aChangedSetOfRefer
     bool               isChanged = false;
     bool               appendToUndoList = false;
 
-    m_frame->Schematic().BuildUnorderedSheetList().GetSymbols( refs, false );
+    m_frame->Schematic().Hierarchy().GetSymbols( refs, false );
 
     DSNLEXER lexer( aChangedSetOfReferences, From_UTF8( __func__ ) );
     PTREE    doc;
@@ -128,7 +128,7 @@ bool SCH_EDITOR_CONTROL::processCmpToFootprintLinkFile( const wxString& aFullFil
 {
     // Build a flat list of symbols in schematic:
     SCH_REFERENCE_LIST referencesList;
-    m_frame->Schematic().BuildUnorderedSheetList().GetSymbols( referencesList, false );
+    m_frame->Schematic().Hierarchy().GetSymbols( referencesList, false );
 
     FILE* cmpFile = wxFopen( aFullFilename, wxT( "rt" ) );
 
diff --git a/eeschema/tools/backannotate.cpp b/eeschema/tools/backannotate.cpp
index 5f587d3de3..83945e0411 100644
--- a/eeschema/tools/backannotate.cpp
+++ b/eeschema/tools/backannotate.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2019 Alexander Shuklin <Jasuramme@gmail.com>
- * Copyright (C) 2004-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2004-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -80,7 +80,7 @@ bool BACK_ANNOTATE::BackAnnotateSymbols( const std::string& aNetlist )
 
     getPcbModulesFromString( aNetlist );
 
-    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = m_frame->Schematic().Hierarchy();
     sheets.GetSymbols( m_refs, false );
     sheets.GetMultiUnitSymbols( m_multiUnitsRefs );
 
diff --git a/eeschema/tools/sch_drawing_tools.cpp b/eeschema/tools/sch_drawing_tools.cpp
index f93088041d..827bd9d0b3 100644
--- a/eeschema/tools/sch_drawing_tools.cpp
+++ b/eeschema/tools/sch_drawing_tools.cpp
@@ -148,7 +148,7 @@ int SCH_DRAWING_TOOLS::PlaceSymbol( const TOOL_EVENT& aEvent )
 
     // First we need to get all instances of this sheet so we can annotate
     // whatever symbols we place on all copies
-    SCH_SHEET_LIST hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST hierarchy = m_frame->Schematic().Hierarchy();
     SCH_SHEET_LIST newInstances =
             hierarchy.FindAllSheetsForScreen( m_frame->GetCurrentSheet().LastScreen() );
     newInstances.SortByPageNumbers();
@@ -2929,7 +2929,7 @@ int SCH_DRAWING_TOOLS::DrawSheet( const TOOL_EVENT& aEvent )
             sheet->SetBackgroundColor( cfg->m_Drawing.default_sheet_background_color );
             sizeSheet( sheet, cursorPos );
 
-            SCH_SHEET_LIST hierarchy = m_frame->Schematic().GetFullHierarchy();
+            SCH_SHEET_LIST hierarchy = m_frame->Schematic().Hierarchy();
             SCH_SHEET_PATH instance = m_frame->GetCurrentSheet();
             instance.push_back( sheet );
             wxString pageNumber;
diff --git a/eeschema/tools/sch_edit_tool.cpp b/eeschema/tools/sch_edit_tool.cpp
index 8f188e333c..c848fca56f 100644
--- a/eeschema/tools/sch_edit_tool.cpp
+++ b/eeschema/tools/sch_edit_tool.cpp
@@ -2086,9 +2086,14 @@ int SCH_EDIT_TOOL::Properties( const TOOL_EVENT& aEvent )
         if( okPressed )
         {
             if( isUndoable )
+            {
                 commit.Push( _( "Edit Sheet Properties" ) );
+            }
             else
+            {
+                m_frame->Schematic().RefreshHierarchy();
                 m_frame->UpdateHierarchyNavigator();
+            }
         }
         else
         {
diff --git a/eeschema/tools/sch_editor_control.cpp b/eeschema/tools/sch_editor_control.cpp
index a3199c282e..c317996f36 100644
--- a/eeschema/tools/sch_editor_control.cpp
+++ b/eeschema/tools/sch_editor_control.cpp
@@ -1656,7 +1656,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
     EDA_ITEMS              loadedItems;
     std::vector<SCH_ITEM*> sortedLoadedItems;
     bool                   sheetsPasted = false;
-    SCH_SHEET_LIST         hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
+    SCH_SHEET_LIST         hierarchy = m_frame->Schematic().Hierarchy();
     SCH_SHEET_PATH&        pasteRoot = m_frame->GetCurrentSheet();
     wxFileName             destFn = pasteRoot.Last()->GetFileName();
 
@@ -1818,7 +1818,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
 
             // Update hierarchy to include any other sheets we already added, avoiding
             // duplicate sheet names
-            hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
+            hierarchy = m_frame->Schematic().Hierarchy();
 
             //@todo: it might be better to just iterate through the sheet names
             // in this screen instead of the whole hierarchy.
@@ -1968,7 +1968,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
 
         // Get a version with correct sheet numbers since we've pasted sheets,
         // we'll need this when annotating next
-        hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
+        hierarchy = m_frame->Schematic().Hierarchy();
     }
 
     std::map<SCH_SHEET_PATH, SCH_REFERENCE_LIST> annotatedSymbols;
@@ -2057,7 +2057,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
     // schematic file.
     prunePastedSymbolInstances();
 
-    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = m_frame->Schematic().Hierarchy();
     SCH_SCREENS    allScreens( m_frame->Schematic().Root() );
 
     allScreens.PruneOrphanedSymbolInstances( m_frame->Prj().GetProjectName(), sheets );
@@ -2278,7 +2278,7 @@ int SCH_EDITOR_CONTROL::IncrementAnnotations( const TOOL_EVENT& aEvent )
         SCH_REFERENCE_LIST references;
 
         if( dlg.m_AllSheets->GetValue() )
-            schematic->BuildSheetListSortedByPageNumbers().GetSymbols( references );
+            schematic->Hierarchy().GetSymbols( references );
         else
             schematic->CurrentSheet().GetSymbols( references );
 
@@ -2665,7 +2665,7 @@ int SCH_EDITOR_CONTROL::RepairSchematic( const TOOL_EVENT& aEvent )
     std::map<KIID, EDA_ITEM*> ids;
     int                       duplicates = 0;
 
-    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = m_frame->Schematic().Hierarchy();
 
     auto processItem =
             [&]( EDA_ITEM* aItem )
diff --git a/eeschema/tools/sch_find_replace_tool.cpp b/eeschema/tools/sch_find_replace_tool.cpp
index 08ca0528ae..680f9a24ab 100644
--- a/eeschema/tools/sch_find_replace_tool.cpp
+++ b/eeschema/tools/sch_find_replace_tool.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2019 CERN
- * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -434,7 +434,7 @@ int SCH_FIND_REPLACE_TOOL::ReplaceAll( const TOOL_EVENT& aEvent )
     }
     else
     {
-        SCH_SHEET_LIST allSheets = m_frame->Schematic().BuildUnorderedSheetList();
+        SCH_SHEET_LIST allSheets = m_frame->Schematic().Hierarchy();
         SCH_SCREENS    screens( m_frame->Schematic().Root() );
 
         for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
diff --git a/eeschema/tools/sch_navigate_tool.cpp b/eeschema/tools/sch_navigate_tool.cpp
index 9c792c8c0d..cc8585827f 100644
--- a/eeschema/tools/sch_navigate_tool.cpp
+++ b/eeschema/tools/sch_navigate_tool.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2019 CERN
- * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023, 2024 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -42,7 +42,7 @@ void SCH_NAVIGATE_TOOL::ResetHistory()
 
 void SCH_NAVIGATE_TOOL::CleanHistory()
 {
-    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
+    SCH_SHEET_LIST sheets = m_frame->Schematic().Hierarchy();
 
     // Search through our history, and removing any entries
     // that the no longer point to a sheet on the schematic
@@ -69,7 +69,7 @@ void SCH_NAVIGATE_TOOL::HypertextCommand( const wxString& href )
     }
     else if( EDA_TEXT::IsGotoPageHref( href, &destPage ) && !destPage.IsEmpty() )
     {
-        for( const SCH_SHEET_PATH& sheet : m_frame->Schematic().BuildSheetListSortedByPageNumbers() )
+        for( const SCH_SHEET_PATH& sheet : m_frame->Schematic().Hierarchy() )
         {
             if( sheet.GetPageNumber() == destPage )
             {
@@ -147,7 +147,7 @@ int SCH_NAVIGATE_TOOL::Previous( const TOOL_EVENT& aEvent )
     if( CanGoPrevious() )
     {
         int targetSheet = m_frame->GetCurrentSheet().GetVirtualPageNumber() - 1;
-        changeSheet( m_frame->Schematic().BuildSheetListSortedByPageNumbers().at( targetSheet - 1 ) );
+        changeSheet( m_frame->Schematic().Hierarchy().at( targetSheet - 1 ) );
     }
     else
     {
@@ -163,7 +163,7 @@ int SCH_NAVIGATE_TOOL::Next( const TOOL_EVENT& aEvent )
     if( CanGoNext() )
     {
         int targetSheet = m_frame->GetCurrentSheet().GetVirtualPageNumber() + 1;
-        changeSheet( m_frame->Schematic().BuildSheetListSortedByPageNumbers().at( targetSheet - 1 ) );
+        changeSheet( m_frame->Schematic().Hierarchy().at( targetSheet - 1 ) );
     }
     else
     {
@@ -201,7 +201,7 @@ bool SCH_NAVIGATE_TOOL::CanGoPrevious()
 bool SCH_NAVIGATE_TOOL::CanGoNext()
 {
     return m_frame->GetCurrentSheet().GetVirtualPageNumber()
-           < (int) m_frame->Schematic().BuildUnorderedSheetList().size();
+           < (int) m_frame->Schematic().Hierarchy().size();
 }