diff --git a/python/core/qgsproject.sip b/python/core/qgsproject.sip
index 8e1f6a19e75..058868db967 100644
--- a/python/core/qgsproject.sip
+++ b/python/core/qgsproject.sip
@@ -630,6 +630,23 @@ Returns the number of registered layers.
  :rtype: bool
 %End
 
+    bool zip();
+%Docstring
+ :rtype: bool
+%End
+
+    QString zipFileName() const;
+%Docstring
+ :rtype: str
+%End
+
+    void setZipFileName( const QString &filename );
+
+    bool unzipped() const;
+%Docstring
+ :rtype: bool
+%End
+
 
     QList<QgsMapLayer *> addMapLayers( const QList<QgsMapLayer *> &mapLayers /Transfer/,
                                        bool addToLegend = true);
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
index 3cf30ae7911..5670cb60e5b 100644
--- a/src/app/qgisapp.cpp
+++ b/src/app/qgisapp.cpp
@@ -5235,10 +5235,12 @@ void QgisApp::fileOpen()
     // Retrieve last used project dir from persistent settings
     QgsSettings settings;
     QString lastUsedDir = settings.value( QStringLiteral( "UI/lastProjectDir" ), QDir::homePath() ).toString();
+    const QString qgs_ext = tr( "QGIS files" ) + " (*.qgs *.QGS)";
+    const QString zip_ext = tr( "QGZ files" ) + " (*.qgz)";
     QString fullPath = QFileDialog::getOpenFileName( this,
                        tr( "Choose a QGIS project file to open" ),
                        lastUsedDir,
-                       tr( "QGIS files" ) + " (*.qgs *.QGS)" );
+                       qgs_ext + ";;" + zip_ext );
     if ( fullPath.isNull() )
     {
       return;
@@ -5271,6 +5273,8 @@ void QgisApp::enableProjectMacros()
   */
 bool QgisApp::addProject( const QString &projectFile )
 {
+  bool zip = ( QFileInfo( projectFile ).suffix() == "qgz" ) ? true : false;
+
   // close the previous opened project if any
   closeProject();
 
@@ -5283,7 +5287,17 @@ bool QgisApp::addProject( const QString &projectFile )
   bool autoSetupOnFirstLayer = mLayerTreeCanvasBridge->autoSetupOnFirstLayer();
   mLayerTreeCanvasBridge->setAutoSetupOnFirstLayer( false );
 
-  if ( !QgsProject::instance()->read( projectFile ) )
+  bool readOk = false;
+  if ( zip )
+  {
+    readOk = QgsProject::instance()->unzip( projectFile );
+  }
+  else
+  {
+    readOk = QgsProject::instance()->read( projectFile );
+  }
+
+  if ( !readOk && !zip )
   {
     QString backupFile = projectFile + "~";
     QString loadBackupPrompt;
@@ -5417,34 +5431,47 @@ bool QgisApp::fileSave()
   // that the project file name is reset to null in fileNew()
   QFileInfo fullPath;
 
-  if ( QgsProject::instance()->fileName().isNull() )
+  if ( QgsProject::instance()->fileName().isNull() && QgsProject::instance()->zipFileName().isNull() )
   {
     // Retrieve last used project dir from persistent settings
     QgsSettings settings;
     QString lastUsedDir = settings.value( QStringLiteral( "UI/lastProjectDir" ), QDir::homePath() ).toString();
 
+    const QString qgs_ext = tr( "QGIS files" ) + " (*.qgs)";
+    const QString zip_ext = tr( "QGZ files" ) + " (*.qgz)";
+    QString filter;
     QString path = QFileDialog::getSaveFileName(
                      this,
                      tr( "Choose a QGIS project file" ),
                      lastUsedDir + '/' + QgsProject::instance()->title(),
-                     tr( "QGIS files" ) + " (*.qgs *.QGS)" );
+                     qgs_ext + ";;" + zip_ext, &filter );
     if ( path.isEmpty() )
       return false;
 
     fullPath.setFile( path );
 
     // make sure we have the .qgs extension in the file name
-    if ( "qgs" != fullPath.suffix().toLower() )
+    if ( filter == zip_ext )
     {
-      fullPath.setFile( fullPath.filePath() + ".qgs" );
+      if ( "qgz" != fullPath.suffix().toLower() )
+        fullPath.setFile( fullPath.filePath() + ".qgz" );
+
+      QgsProject::instance()->setZipFileName( fullPath.filePath() );
     }
+    else
+    {
+      if ( "qgs" != fullPath.suffix().toLower() )
+        fullPath.setFile( fullPath.filePath() + ".qgs" );
 
-
-    QgsProject::instance()->setFileName( fullPath.filePath() );
+      QgsProject::instance()->setFileName( fullPath.filePath() );
+    }
   }
   else
   {
     QFileInfo fi( QgsProject::instance()->fileName() );
+    if ( QgsProject::instance()->unzipped() )
+      fi.setFile( QgsProject::instance()->zipFileName() );
+
     fullPath = fi.absoluteFilePath();
     if ( fi.exists() && !mProjectLastModified.isNull() && mProjectLastModified != fi.lastModified() )
     {
@@ -5468,20 +5495,34 @@ bool QgisApp::fileSave()
     }
   }
 
-  if ( QgsProject::instance()->write() )
+  bool writeOk = false;
+  QString writtenFileName;
+
+  if ( QgsProject::instance()->unzipped() )
+  {
+    writeOk = QgsProject::instance()->zip();
+    writtenFileName = QgsProject::instance()->zipFileName();
+  }
+  else
+  {
+    writeOk = QgsProject::instance()->write();
+    writtenFileName = QgsProject::instance()->fileName();
+  }
+
+  if ( writeOk )
   {
     setTitleBarText_( *this ); // update title bar
-    mStatusBar->showMessage( tr( "Saved project to: %1" ).arg( QDir::toNativeSeparators( QgsProject::instance()->fileName() ) ), 5000 );
+    mStatusBar->showMessage( tr( "Saved project to: %1" ).arg( QDir::toNativeSeparators( writtenFileName ) ), 5000 );
 
     saveRecentProjectPath( fullPath.filePath() );
 
-    QFileInfo fi( QgsProject::instance()->fileName() );
+    QFileInfo fi( writtenFileName );
     mProjectLastModified = fi.lastModified();
   }
   else
   {
     QMessageBox::critical( this,
-                           tr( "Unable to save project %1" ).arg( QDir::toNativeSeparators( QgsProject::instance()->fileName() ) ),
+                           tr( "Unable to save project %1" ).arg( QDir::toNativeSeparators( writtenFileName ) ),
                            QgsProject::instance()->error() );
     return false;
   }
@@ -5501,10 +5542,13 @@ void QgisApp::fileSaveAs()
   QgsSettings settings;
   QString lastUsedDir = settings.value( QStringLiteral( "UI/lastProjectDir" ), QDir::homePath() ).toString();
 
+  const QString qgs_ext = tr( "QGIS files" ) + " (*.qgs *.QGS)";
+  const QString zip_ext = tr( "QGZ files" ) + " (*.qgz)";
+  QString filter;
   QString path = QFileDialog::getSaveFileName( this,
                  tr( "Choose a file name to save the QGIS project file as" ),
                  lastUsedDir + '/' + QgsProject::instance()->title(),
-                 tr( "QGIS files" ) + " (*.qgs *.QGS)" );
+                 qgs_ext + ";;" + zip_ext, &filter );
   if ( path.isEmpty() )
     return;
 
@@ -5512,18 +5556,27 @@ void QgisApp::fileSaveAs()
 
   settings.setValue( QStringLiteral( "UI/lastProjectDir" ), fullPath.path() );
 
-  // make sure the .qgs extension is included in the path name. if not, add it...
-  if ( "qgs" != fullPath.suffix().toLower() )
+  bool writeOk = false;
+  if ( filter == zip_ext )
   {
-    fullPath.setFile( fullPath.filePath() + ".qgs" );
+    if ( "qgz" != fullPath.suffix().toLower() )
+      fullPath.setFile( fullPath.filePath() + ".qgz" );
+
+    writeOk = QgsProject::instance()->zip( fullPath.filePath() );
+  }
+  else // .qgs
+  {
+    if ( "qgs" != fullPath.suffix().toLower() )
+      fullPath.setFile( fullPath.filePath() + ".qgs" );
+
+    QgsProject::instance()->setFileName( fullPath.filePath() );
+    writeOk = QgsProject::instance()->write();
   }
 
-  QgsProject::instance()->setFileName( fullPath.filePath() );
-
-  if ( QgsProject::instance()->write() )
+  if ( writeOk )
   {
     setTitleBarText_( *this ); // update title bar
-    mStatusBar->showMessage( tr( "Saved project to: %1" ).arg( QDir::toNativeSeparators( QgsProject::instance()->fileName() ) ), 5000 );
+    mStatusBar->showMessage( tr( "Saved project to: %1" ).arg( QDir::toNativeSeparators( fullPath.filePath() ) ), 5000 );
     // add this to the list of recently used project files
     saveRecentProjectPath( fullPath.filePath() );
     mProjectLastModified = fullPath.lastModified();
diff --git a/src/core/qgsarchive.cpp b/src/core/qgsarchive.cpp
index 1e9563157b0..6d6adcb73f5 100644
--- a/src/core/qgsarchive.cpp
+++ b/src/core/qgsarchive.cpp
@@ -95,6 +95,11 @@ QString QgsArchive::filename() const
   return mFilename;
 }
 
+void QgsArchive::setFileName( const QString &filename )
+{
+  mFilename = filename;
+}
+
 QString QgsArchive::projectFile() const
 {
   Q_FOREACH ( const QString &file, mFiles )
diff --git a/src/core/qgsarchive.h b/src/core/qgsarchive.h
index 7dd55ca5640..8cd58e786ca 100644
--- a/src/core/qgsarchive.h
+++ b/src/core/qgsarchive.h
@@ -49,6 +49,8 @@ class CORE_EXPORT QgsArchive
 
     void addFile( const QString &filename );
 
+    void setFileName( const QString &filename );
+
     QString filename() const;
 
     QString projectFile() const;
diff --git a/src/core/qgsproject.cpp b/src/core/qgsproject.cpp
index 0a7e6a3e915..ca2d30fe0e9 100644
--- a/src/core/qgsproject.cpp
+++ b/src/core/qgsproject.cpp
@@ -425,6 +425,8 @@ void QgsProject::setFileName( const QString &name )
   if ( newHomePath != oldHomePath )
     emit homePathChanged();
 
+  mArchive->clear();
+
   setDirty( true );
 }
 
@@ -763,6 +765,9 @@ bool QgsProject::read()
 {
   clearError();
 
+  if ( ! mUnzipping )
+    mArchive->clear();
+
   std::unique_ptr<QDomDocument> doc( new QDomDocument( QStringLiteral( "qgis" ) ) );
 
   if ( !mFile.open( QIODevice::ReadOnly | QIODevice::Text ) )
@@ -2085,27 +2090,38 @@ bool QgsProject::unzip( const QString &filename )
   }
 
   // read the project file
+  mUnzipping = true;
   if ( ! read( archive->projectFile() ) )
   {
+    mUnzipping = false;
     setError( tr( "Cannot read unzipped qgs project file" ) );
     return false;
   }
 
   // keep the archive
+  mUnzipping = false;
   mArchive.reset( archive.release() );
 
   return true;
 }
 
+bool QgsProject::zip()
+{
+  if ( unzipped() )
+    return zip( mArchive->filename() );
+
+  return false;
+}
+
 bool QgsProject::zip( const QString &filename )
 {
   clearError();
 
   // save the current project in a temporary .qgs file
-  QgsArchive archive;
+  std::unique_ptr<QgsArchive> archive( new QgsArchive() );
   const QString baseName = QFileInfo( filename ).baseName();
   const QString qgsFileName = QString( "%1.qgs" ).arg( baseName );
-  QFile qgsFile( QDir( archive.dir() ).filePath( qgsFileName ) );
+  QFile qgsFile( QDir( archive->dir() ).filePath( qgsFileName ) );
 
   bool writeOk;
   if ( qgsFile.open( QIODevice::WriteOnly ) )
@@ -2127,19 +2143,38 @@ bool QgsProject::zip( const QString &filename )
   }
 
   // create the archive
-  archive.addFile( qgsFile.fileName() );
+  archive->addFile( qgsFile.fileName() );
 
   // zip
   QString errMsg;
-  if ( !archive.zip( filename ) )
+  if ( !archive->zip( filename ) )
   {
     setError( tr( "Unable to perform zip" ) );
     return false;
   }
 
+  // keep the archive
+  mArchive.reset( archive.release() );
+
   return true;
 }
 
+bool QgsProject::unzipped() const
+{
+  return !mArchive->filename().isEmpty();
+}
+
+QString QgsProject::zipFileName() const
+{
+  return mArchive->filename();
+}
+
+void QgsProject::setZipFileName( const QString &filename )
+{
+  mArchive.reset( new QgsArchive() );
+  mArchive->setFileName( filename );
+}
+
 QList<QgsMapLayer *> QgsProject::addMapLayers(
   const QList<QgsMapLayer *> &layers,
   bool addToLegend,
diff --git a/src/core/qgsproject.h b/src/core/qgsproject.h
index d32b52064d8..2046f4c7df4 100644
--- a/src/core/qgsproject.h
+++ b/src/core/qgsproject.h
@@ -592,6 +592,14 @@ class CORE_EXPORT QgsProject : public QObject, public QgsExpressionContextGenera
      */
     bool zip( const QString &filename );
 
+    bool zip();
+
+    QString zipFileName() const;
+
+    void setZipFileName( const QString &filename );
+
+    bool unzipped() const;
+
 #ifndef SIP_RUN
 
     /** Returns a list of registered map layers with a specified layer type.
@@ -1066,6 +1074,7 @@ class CORE_EXPORT QgsProject : public QObject, public QgsExpressionContextGenera
     QVariantMap mCustomVariables;
 
     std::unique_ptr<QgsArchive> mArchive;
+    bool mUnzipping;
 
     QFile mFile;                 // current physical project file
     mutable QgsProjectPropertyKey mProperties;  // property hierarchy, TODO: this shouldn't be mutable