diff --git a/bridge.cpp b/bridge.cpp
index 6fc172bd7a..7e529f2c6e 100644
--- a/bridge.cpp
+++ b/bridge.cpp
@@ -208,6 +208,11 @@ bool Bridge::compositingActive() const
     return c->workspace()->compositingActive();
     }
 
+QRect Bridge::transparentRect() const
+    {
+    return c->transparentRect().translated(-c->decorationRect().topLeft());
+    }
+
 bool Bridge::isClientGroupActive()
     {
     return c->clientGroup()->containsActiveClient();
diff --git a/bridge.h b/bridge.h
index 05836d11c2..9bd446ccd9 100644
--- a/bridge.h
+++ b/bridge.h
@@ -76,6 +76,7 @@ class Bridge : public KDecorationBridgeUnstable
         virtual void grabXServer( bool grab );
 
         virtual bool compositingActive() const;
+        virtual QRect transparentRect() const;
 
         // Window tabbing
         virtual bool isClientGroupActive();
diff --git a/client.cpp b/client.cpp
index 4a83290867..258ed6d8cb 100644
--- a/client.cpp
+++ b/client.cpp
@@ -445,13 +445,23 @@ void Client::layoutDecorationRects(QRect &left, QRect &top, QRect &right, QRect
     if (mode == WindowRelative)
         r.translate(-padding_left, -padding_top);
 
-    top = QRect(r.x(), r.y(), r.width(), padding_top + border_top);
-    bottom = QRect(r.x(), r.y() + r.height() - padding_bottom - border_bottom,
-                   r.width(), padding_bottom + border_bottom);
+    NETStrut strut = info->frameOverlap();
+    if (strut.left == -1 && strut.top == -1 && strut.right == -1 && strut.bottom == -1)
+        {
+        top = QRect(r.x(), r.y(), r.width(), r.height() / 3);
+        left = QRect(r.x(), r.y() + top.height(), width() / 2, r.height() / 3);
+        right = QRect(r.x() + left.width(), r.y() + top.height(), r.width() - left.width(), left.height());
+        bottom = QRect(r.x(), r.y() + top.height() + left.height(), r.width(), r.height() - left.height() - top.height());
+        return;
+        }
+
+    top = QRect(r.x(), r.y(), r.width(), padding_top + border_top + strut.top);
+    bottom = QRect(r.x(), r.y() + r.height() - padding_bottom - border_bottom - strut.bottom,
+                   r.width(), padding_bottom + border_bottom + strut.bottom);
     left = QRect(r.x(), r.y() + top.height(),
-                 padding_left + border_left, r.height() - top.height() - bottom.height());
-    right = QRect(r.x() + r.width() - padding_right - border_right, r.y() + top.height(),
-                  padding_right + border_right, r.height() - top.height() - bottom.height());
+                 padding_left + border_left + strut.left, r.height() - top.height() - bottom.height());
+    right = QRect(r.x() + r.width() - padding_right - border_right - strut.right, r.y() + top.height(),
+                  padding_right + border_right + strut.right, r.height() - top.height() - bottom.height());
     }
 
 QRegion Client::decorationPendingRegion() const
@@ -581,6 +591,20 @@ void Client::resizeDecorationPixmaps()
     triggerDecorationRepaint();
     }
 
+QRect Client::transparentRect() const
+    {
+    NETStrut strut = info->frameOverlap();
+    if (strut.left == -1 && strut.top == -1 && strut.right == -1 && strut.bottom == -1)
+        return QRect();
+
+    const QRect r = QRect(clientPos(), clientSize())
+                        .adjusted(strut.left, strut.top, -strut.right, -strut.bottom);
+    if (r.isValid())
+        return r;
+
+    return QRect();
+    }
+
 void Client::detectNoBorder()
     {
     if( shape())
diff --git a/client.h b/client.h
index 5266b1959c..e97ceb7c79 100644
--- a/client.h
+++ b/client.h
@@ -358,6 +358,8 @@ class Client
                         QRect(0, 0, width(), height());
         }
 
+        QRect transparentRect() const;
+
         QRegion decorationPendingRegion() const;
 
         enum CoordinateMode {
diff --git a/deleted.cpp b/deleted.cpp
index e5fef3d833..cde2c34bc2 100644
--- a/deleted.cpp
+++ b/deleted.cpp
@@ -68,6 +68,7 @@ void Deleted::copyToDeleted( Toplevel* c )
     Toplevel::copyToDeleted( c );
     desk = c->desktop();
     contentsRect = QRect( c->clientPos(), c->clientSize());
+    transparent_rect = c->transparentRect();
     if( WinInfo* cinfo = dynamic_cast< WinInfo* >( info ))
         cinfo->disable();
     Client* client = dynamic_cast<Client*>(c);
@@ -138,6 +139,11 @@ QRect Deleted::decorationRect() const
     return rect().adjusted(-padding_left, -padding_top, padding_top, padding_bottom);
     }
 
+QRect Deleted::transparentRect() const
+    {
+    return transparent_rect;
+    }
+
 } // namespace
 
 #include "deleted.moc"
diff --git a/deleted.h b/deleted.h
index d3aedb880d..94fda09b3f 100644
--- a/deleted.h
+++ b/deleted.h
@@ -39,6 +39,7 @@ class Deleted
         virtual int desktop() const;
         virtual QPoint clientPos() const;
         virtual QSize clientSize() const;
+        virtual QRect transparentRect() const;
         const QPixmap *topDecoPixmap() const { return &decorationPixmapTop; }
         const QPixmap *leftDecoPixmap() const { return &decorationPixmapLeft; }
         const QPixmap *bottomDecoPixmap() const { return &decorationPixmapBottom; }
@@ -58,6 +59,7 @@ class Deleted
         double window_opacity;
         int desk;
         QRect contentsRect; // for clientPos()/clientSize()
+        QRect transparent_rect;
 
         QPixmap decorationPixmapLeft;
         QPixmap decorationPixmapRight;
diff --git a/events.cpp b/events.cpp
index dcac6dc9e3..2431526d72 100644
--- a/events.cpp
+++ b/events.cpp
@@ -634,6 +634,10 @@ bool Client::windowEvent( XEvent* e )
                 i.setOpacity( info->opacity());
                 }
             }
+        if( dirty[ WinInfo::PROTOCOLS2 ] & NET::WM2FrameOverlap )
+            {
+            // ### Inform the decoration
+            }
         }
 
     switch (e->type) 
diff --git a/kcmkwin/kwindecoration/preview.cpp b/kcmkwin/kwindecoration/preview.cpp
index ee15707be6..55f0339736 100644
--- a/kcmkwin/kwindecoration/preview.cpp
+++ b/kcmkwin/kwindecoration/preview.cpp
@@ -467,6 +467,11 @@ bool KDecorationPreviewBridge::compositingActive() const
     return KWindowSystem::compositingActive();
     }
 
+QRect KDecorationPreviewBridge::transparentRect() const
+    {
+    return QRect();
+    }
+
 // Window tabbing
 
 bool KDecorationPreviewBridge::isClientGroupActive()
diff --git a/kcmkwin/kwindecoration/preview.h b/kcmkwin/kwindecoration/preview.h
index 473d154151..fab1783e07 100644
--- a/kcmkwin/kwindecoration/preview.h
+++ b/kcmkwin/kwindecoration/preview.h
@@ -115,6 +115,7 @@ class KDecorationPreviewBridge
         virtual void grabXServer( bool grab );
 
         virtual bool compositingActive() const;
+        virtual QRect transparentRect() const;
 
         // Window tabbing
         virtual bool isClientGroupActive();
diff --git a/lib/kcommondecoration.cpp b/lib/kcommondecoration.cpp
index 750589b798..67d126f972 100644
--- a/lib/kcommondecoration.cpp
+++ b/lib/kcommondecoration.cpp
@@ -932,6 +932,10 @@ QRect KCommonDecoration::titleRect() const
               titleEdgeBottomBottom-(r_y+titleEdgeTop) );
 }
 
+QRect KCommonDecoration::transparentRect() const
+{
+    return wrapper->transparentRect();
+}
 
 KCommonDecorationButton::KCommonDecorationButton(ButtonType type, KCommonDecoration *parent)
     : QAbstractButton(parent?parent->widget():0 ),
diff --git a/lib/kcommondecoration.h b/lib/kcommondecoration.h
index f62f1415f0..114b680a39 100644
--- a/lib/kcommondecoration.h
+++ b/lib/kcommondecoration.h
@@ -233,6 +233,22 @@ class KWIN_EXPORT KCommonDecoration : public QObject, public KDecorationDefines
          */
         QRect titleRect() const;
 
+        /**
+         * Returns the rectangle within the decoration that should be transparent.
+         *
+         * Usually this is the rectangle occupied by the client window,
+         * but a smaller rectangle may be returned if the client has specified
+         * that the window decoration should extend below the client area.
+         *
+         * If the client has requested that the decoration should cover the whole
+         * client area, a null rectangle is returned.
+         *
+         * The returned rectangle is never larger than the client area.
+         *
+         * @since 4.4
+         */
+        QRect transparentRect() const;
+
     public:
         /**
          * Handles widget and layout creation, call the base implementation when subclassing this member.
diff --git a/lib/kdecoration.cpp b/lib/kdecoration.cpp
index e9ae5f9e3e..5085a86f6e 100644
--- a/lib/kdecoration.cpp
+++ b/lib/kdecoration.cpp
@@ -382,6 +382,14 @@ KDecoration::Position KDecoration::mousePosition( const QPoint& p ) const
     return m;
     }
 
+QRect KDecoration::transparentRect() const
+    {
+    if (KDecorationBridgeUnstable *bridge2 = dynamic_cast<KDecorationBridgeUnstable*>(bridge_))
+        return bridge2->transparentRect();
+    else
+        return QRect();
+    }
+
 
 KDecorationUnstable::KDecorationUnstable( KDecorationBridge* bridge, KDecorationFactory* factory )
     : KDecoration( bridge, factory )
diff --git a/lib/kdecoration.h b/lib/kdecoration.h
index 6170ac019f..728eaae7c4 100644
--- a/lib/kdecoration.h
+++ b/lib/kdecoration.h
@@ -628,6 +628,20 @@ class KWIN_EXPORT KDecoration
          * Convenience function that returns the height of the decoration.
          */
         int height() const;  // convenience
+        /**
+         * Returns the rectangle within the window frame that should be transparent.
+         * Usually this rectangle is the same as the client area, and it is never
+         * larger.
+         *
+         * If the client has requested that the window frame is extended into the
+         * client area, this rectangle is smaller than the client area.
+         *
+         * If the window frame should cover the whole client area, a null rectangle
+         * is returned.
+         *
+         * @since 4.4
+         */
+        QRect transparentRect() const;
         /**
          * This function is the default handler for mouse events. All mouse events
          * that are not handled by the decoration itself should be passed to it
diff --git a/lib/kdecorationbridge.h b/lib/kdecorationbridge.h
index 09614cc680..f4f2fb44ac 100644
--- a/lib/kdecorationbridge.h
+++ b/lib/kdecorationbridge.h
@@ -94,6 +94,7 @@ class KWIN_EXPORT KDecorationBridgeUnstable
     {
     public:
         virtual bool compositingActive() const = 0;
+        virtual QRect transparentRect() const = 0;
 
         // Window tabbing
         virtual bool isClientGroupActive() = 0;
diff --git a/manage.cpp b/manage.cpp
index 88f69c3e76..397d67d163 100644
--- a/manage.cpp
+++ b/manage.cpp
@@ -91,6 +91,7 @@ bool Client::manage( Window w, bool isMapped )
         NET::WM2ExtendedStrut |
         NET::WM2Opacity |
         NET::WM2FullscreenMonitors |
+        NET::WM2FrameOverlap |
         0;
 
     info = new WinInfo( this, display(), client, rootWindow(), properties, 2 );
diff --git a/scene.cpp b/scene.cpp
index 4951693ca0..bd047229c4 100644
--- a/scene.cpp
+++ b/scene.cpp
@@ -482,10 +482,11 @@ WindowQuadList Scene::Window::buildQuads( bool force ) const
         {
         Client *client = dynamic_cast<Client*>( toplevel );
         QRegion contents = clientShape();
+        QRegion center = client->transparentRect();
         QRegion decoration = (client && Workspace::self()->decorationHasAlpha() ?
-                              QRegion(client->decorationRect()) : shape()) - contents;
+                              QRegion(client->decorationRect()) : shape()) - center;
         ret = makeQuads( WindowQuadContents, contents );
-        if( (client && !client->isShade()) || !client )
+        if( !client || !(center.isEmpty() || client->isShade()) )
             ret += makeQuads( WindowQuadDecoration, decoration );
         else
             {
diff --git a/toplevel.h b/toplevel.h
index 19be1c436f..b8ebfc268e 100644
--- a/toplevel.h
+++ b/toplevel.h
@@ -66,6 +66,7 @@ class Toplevel
         virtual QSize clientSize() const = 0;
         virtual QRect visibleRect() const; // the area the window occupies on the screen
         virtual QRect decorationRect() const; // rect including the decoration shadows
+        virtual QRect transparentRect() const = 0;
         virtual QRegion decorationPendingRegion() const; // decoration region that needs to be repainted
 
         // prefer isXXX() instead
diff --git a/unmanaged.cpp b/unmanaged.cpp
index 083f9c265c..31ceb7187f 100644
--- a/unmanaged.cpp
+++ b/unmanaged.cpp
@@ -122,6 +122,11 @@ QSize Unmanaged::clientSize() const
     return size();
     }
 
+QRect Unmanaged::transparentRect() const
+    {
+    return QRect(clientPos(), clientSize());
+    }
+
 void Unmanaged::debug( kdbgstream& stream ) const
     {
     stream << "\'ID:" << window() << "\'";
diff --git a/unmanaged.h b/unmanaged.h
index 42c4f9299a..708d339d0b 100644
--- a/unmanaged.h
+++ b/unmanaged.h
@@ -41,6 +41,7 @@ class Unmanaged
         virtual int desktop() const;
         virtual QPoint clientPos() const;
         virtual QSize clientSize() const;
+        virtual QRect transparentRect() const;
     protected:
         virtual void debug( kdbgstream& stream ) const;
         virtual bool shouldUnredirect() const;
diff --git a/workspace.cpp b/workspace.cpp
index eaf9e6a44a..428289cc9d 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -324,6 +324,7 @@ void Workspace::init()
         NET::WM2DesktopLayout |
         NET::WM2FullPlacement |
         NET::WM2FullscreenMonitors |
+        NET::WM2FrameOverlap |
         0
         ,
         NET::ActionMove |