diff --git a/src/Avalonia.Controls.Recycling/ControlRecycling.cs b/src/Avalonia.Controls.Recycling/ControlRecycling.cs
index 3ab13c5a..fd328200 100644
--- a/src/Avalonia.Controls.Recycling/ControlRecycling.cs
+++ b/src/Avalonia.Controls.Recycling/ControlRecycling.cs
@@ -73,9 +73,6 @@ public void Add(object data, object control)
 
         if (TryToUseIdAsKey && data is IControlRecyclingIdProvider idProvider)
         {
-#if DEBUG
-            Console.WriteLine($"Build: {data}, Id='{idProvider.GetControlRecyclingId()}'");
-#endif
             if (!string.IsNullOrWhiteSpace(idProvider.GetControlRecyclingId()))
             {
                 key = idProvider.GetControlRecyclingId();
@@ -84,9 +81,6 @@ public void Add(object data, object control)
 
         if (TryGetValue(key, out var control))
         {
-#if DEBUG
-            Console.WriteLine($"[Cached] {key}, {control}");
-#endif
             return control;
         }
 
@@ -99,9 +93,7 @@ public void Add(object data, object control)
         }
 
         Add(key, control);
-#if DEBUG
-        Console.WriteLine($"[Added] {key}, {control}");
-#endif
+
         return control;
     }
 
diff --git a/src/Dock.Avalonia/Controls/ProportionalDockControl.axaml b/src/Dock.Avalonia/Controls/ProportionalDockControl.axaml
index 32976b69..a814f9ba 100644
--- a/src/Dock.Avalonia/Controls/ProportionalDockControl.axaml
+++ b/src/Dock.Avalonia/Controls/ProportionalDockControl.axaml
@@ -1,7 +1,8 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:converters="using:Dock.Avalonia.Converters"
-                    xmlns:core="using:Dock.Model.Core">
+                    xmlns:core="using:Dock.Model.Core"
+                    xmlns:dmc="using:Dock.Model.Controls">
   <Design.PreviewWith>
     <ProportionalDockControl Width="300" Height="300" />
   </Design.PreviewWith>
@@ -11,13 +12,16 @@
     <Setter Property="Template">
       <ControlTemplate>
         <DockableControl TrackingMode="Visible">
-          <ItemsControl ItemsSource="{Binding VisibleDockables}">
+          <ItemsControl ItemsSource="{Binding VisibleDockables}" 
+                        x:DataType="dmc:IProportionalDock">
             <ItemsControl.Styles>
               <Style Selector="ItemsControl > ContentPresenter">
-                <Setter x:DataType="core:IDock" Property="(ProportionalStackPanel.Proportion)" Value="{Binding Proportion}" />
+                <Setter x:DataType="core:IDockable" 
+                        Property="(ProportionalStackPanel.Proportion)" 
+                        Value="{Binding Proportion}" />
                 <Setter Property="(ProportionalStackPanel.IsCollapsed)">
                   <Setter.Value>
-                    <MultiBinding Converter="{x:Static BoolConverters.And}" x:DataType="core:IDock">
+                    <MultiBinding Converter="{x:Static BoolConverters.And}" x:DataType="core:IDockable">
                       <CompiledBinding Path="IsCollapsable" />
                       <CompiledBinding Path="IsEmpty" />
                     </MultiBinding>
@@ -29,6 +33,7 @@
               <ItemsPanelTemplate>
                 <ProportionalStackPanel DockProperties.IsDropArea="True"
                                         Background="Transparent"
+                                        x:DataType="dmc:IProportionalDock" 
                                         Orientation="{Binding Orientation, Converter={x:Static converters:OrientationConverter.Instance}}" />
               </ItemsPanelTemplate>
             </ItemsControl.ItemsPanel>
diff --git a/src/Dock.Avalonia/Controls/RootDockControl.axaml b/src/Dock.Avalonia/Controls/RootDockControl.axaml
index 5a5605cc..ebf63516 100644
--- a/src/Dock.Avalonia/Controls/RootDockControl.axaml
+++ b/src/Dock.Avalonia/Controls/RootDockControl.axaml
@@ -17,19 +17,19 @@
             <ToolPinnedControl DockPanel.Dock="Left" 
                                Orientation="Vertical"
                                Items="{Binding LeftPinnedDockables}"
-                               IsVisible="{Binding !!LeftPinnedDockables.Count}" />
+                               IsVisible="{Binding !!LeftPinnedDockables.Count, FallbackValue={x:False}}" />
             <ToolPinnedControl DockPanel.Dock="Right" 
                                Orientation="Vertical"
                                Items="{Binding RightPinnedDockables}"
-                               IsVisible="{Binding !!RightPinnedDockables.Count}" />
+                               IsVisible="{Binding !!RightPinnedDockables.Count, FallbackValue={x:False}}" />
             <ToolPinnedControl DockPanel.Dock="Top" 
                                Orientation="Horizontal"
                                Items="{Binding TopPinnedDockables}"
-                               IsVisible="{Binding !!TopPinnedDockables.Count}" />
+                               IsVisible="{Binding !!TopPinnedDockables.Count, FallbackValue={x:False}}" />
             <ToolPinnedControl DockPanel.Dock="Bottom" 
                                Orientation="Horizontal"
                                Items="{Binding BottomPinnedDockables}"
-                               IsVisible="{Binding !!BottomPinnedDockables.Count}" />
+                               IsVisible="{Binding !!BottomPinnedDockables.Count, FallbackValue={x:False}}" />
             <Panel>
               <ContentControl Content="{Binding ActiveDockable}" Name="PART_MainContent" />
               <PinnedDockControl />
diff --git a/src/Dock.Avalonia/Controls/ToolChromeControl.axaml b/src/Dock.Avalonia/Controls/ToolChromeControl.axaml
index c43c6d98..8dc26982 100644
--- a/src/Dock.Avalonia/Controls/ToolChromeControl.axaml
+++ b/src/Dock.Avalonia/Controls/ToolChromeControl.axaml
@@ -50,7 +50,7 @@
     <Setter Property="BorderThickness" Value="0" />
     <Setter Property="Padding" Value="0" />
     <Setter Property="IsPinned" Value="{CompiledBinding ActiveDockable.OriginalOwner, FallbackValue=False, Converter={x:Static ObjectConverters.IsNotNull}}" x:DataType="controls:IToolDock" />
-    <Setter Property="IsMaximized" Value="{CompiledBinding $parent[HostWindow].WindowState, FallbackValue=False, Converter={x:Static IsMaximizedConverter.Instance}}" />
+    <Setter Property="IsMaximized" Value="{CompiledBinding $parent[Window].WindowState, FallbackValue=False, Converter={x:Static IsMaximizedConverter.Instance}}" />
 
     <Setter Property="Template">
       <ControlTemplate>
diff --git a/src/Dock.Model.Avalonia/Controls/TemplateHelper.cs b/src/Dock.Model.Avalonia/Controls/TemplateHelper.cs
index f8d20a2e..837ec4ab 100644
--- a/src/Dock.Model.Avalonia/Controls/TemplateHelper.cs
+++ b/src/Dock.Model.Avalonia/Controls/TemplateHelper.cs
@@ -21,9 +21,6 @@ internal static class TemplateHelper
         {
             if (controlRecycling.TryGetValue(content, out var control))
             {
-#if DEBUG
-                Console.WriteLine($"[Cached] {content}, {control}");
-#endif
                 return control as Control;
             }
 
@@ -31,9 +28,6 @@ internal static class TemplateHelper
             if (control is not null)
             {
                 controlRecycling.Add(content, control);
-#if DEBUG
-                Console.WriteLine($"[Added] {content}, {control}");
-#endif
             }
 
             return control as Control;
diff --git a/src/Dock.Model.Avalonia/Core/DockBase.cs b/src/Dock.Model.Avalonia/Core/DockBase.cs
index d08ee14e..5da5a775 100644
--- a/src/Dock.Model.Avalonia/Core/DockBase.cs
+++ b/src/Dock.Model.Avalonia/Core/DockBase.cs
@@ -51,13 +51,7 @@ public abstract class DockBase : DockableBase, IDock
         AvaloniaProperty.RegisterDirect<DockBase, IDockable?>(nameof(FocusedDockable), o => o.FocusedDockable, (o, v) => o.FocusedDockable = v);
 
     /// <summary>
-    /// Defines the <see cref="Proportion"/> property.
-    /// </summary>
-    public static readonly DirectProperty<DockBase, double> ProportionProperty =
-        AvaloniaProperty.RegisterDirect<DockBase, double>(nameof(Proportion), o => o.Proportion, (o, v) => o.Proportion = v, double.NaN);
-
-    /// <summary>
-    /// Defines the <see cref="Proportion"/> property.
+    /// Defines the <see cref="Dock"/> property.
     /// </summary>
     public static readonly DirectProperty<DockBase, DockMode> DockProperty =
         AvaloniaProperty.RegisterDirect<DockBase, DockMode>(nameof(Dock), o => o.Dock, (o, v) => o.Dock = v);
@@ -68,24 +62,12 @@ public abstract class DockBase : DockableBase, IDock
     public static readonly DirectProperty<DockBase, bool> IsActiveProperty =
         AvaloniaProperty.RegisterDirect<DockBase, bool>(nameof(IsActive), o => o.IsActive, (o, v) => o.IsActive = v);
 
-    /// <summary>
-    /// Defines the <see cref="IsEmpty"/> property.
-    /// </summary>
-    public static readonly DirectProperty<DockBase, bool> IsEmptyProperty =
-        AvaloniaProperty.RegisterDirect<DockBase, bool>(nameof(IsEmpty), o => o.IsEmpty, (o, v) => o.IsEmpty = v);
-
     /// <summary>
     /// Defines the <see cref="OpenedDockablesCount"/> property.
     /// </summary>
     public static readonly DirectProperty<DockBase, int> OpenedDockablesCountProperty =
         AvaloniaProperty.RegisterDirect<DockBase, int>(nameof(OpenedDockablesCount), o => o.OpenedDockablesCount, (o, v) => o.OpenedDockablesCount = v);
 
-    /// <summary>
-    /// Defines the <see cref="IsCollapsable"/> property.
-    /// </summary>
-    public static readonly DirectProperty<DockBase, bool> IsCollapsableProperty =
-        AvaloniaProperty.RegisterDirect<DockBase, bool>(nameof(IsCollapsable), o => o.IsCollapsable, (o, v) => o.IsCollapsable = v, true);
-
     /// <summary>
     /// Defines the <see cref="CanGoBack"/> property.
     /// </summary>
@@ -103,11 +85,8 @@ public abstract class DockBase : DockableBase, IDock
     private IDockable? _activeDockable;
     private IDockable? _defaultDockable;
     private IDockable? _focusedDockable;
-    private double _proportion = double.NaN;
     private DockMode _dock = DockMode.Center;
     private bool _isActive;
-    private bool _isEmpty;
-    private bool _isCollapsable = true;
     private bool _canGoBack;
     private bool _canGoForward;
     private int _openedDockablesCount;
@@ -175,15 +154,6 @@ public IDockable? FocusedDockable
         }
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    [JsonPropertyName("Proportion")]
-    public double Proportion
-    {
-        get => _proportion;
-        set => SetAndRaise(ProportionProperty, ref _proportion, value);
-    }
-
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     [JsonPropertyName("Dock")]
@@ -202,15 +172,6 @@ public bool IsActive
         set => SetAndRaise(IsActiveProperty, ref _isActive, value);
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    [JsonPropertyName("IsEmpty")]
-    public bool IsEmpty
-    {
-        get => _isEmpty;
-        set => SetAndRaise(IsEmptyProperty, ref _isEmpty, value);
-    }
-
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     [JsonIgnore]
@@ -220,15 +181,6 @@ public int OpenedDockablesCount
         set => SetAndRaise(OpenedDockablesCountProperty, ref _openedDockablesCount, value);
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    [JsonPropertyName("IsCollapsable")]
-    public bool IsCollapsable
-    {
-        get => _isCollapsable;
-        set => SetAndRaise(IsCollapsableProperty, ref _isCollapsable, value);
-    }
-
     /// <inheritdoc/>
     [IgnoreDataMember]
     [JsonIgnore]
diff --git a/src/Dock.Model.Avalonia/Core/DockableBase.cs b/src/Dock.Model.Avalonia/Core/DockableBase.cs
index 2e30c004..74ebd58b 100644
--- a/src/Dock.Model.Avalonia/Core/DockableBase.cs
+++ b/src/Dock.Model.Avalonia/Core/DockableBase.cs
@@ -60,6 +60,24 @@ public abstract class DockableBase : StyledElement, IDockable
     public static readonly DirectProperty<DockableBase, IFactory?> FactoryProperty =
         AvaloniaProperty.RegisterDirect<DockableBase, IFactory?>(nameof(Factory), o => o.Factory, (o, v) => o.Factory = v);
 
+    /// <summary>
+    /// Defines the <see cref="IsEmpty"/> property.
+    /// </summary>
+    public static readonly DirectProperty<DockableBase, bool> IsEmptyProperty =
+        AvaloniaProperty.RegisterDirect<DockableBase, bool>(nameof(IsEmpty), o => o.IsEmpty, (o, v) => o.IsEmpty = v);
+
+    /// <summary>
+    /// Defines the <see cref="IsCollapsable"/> property.
+    /// </summary>
+    public static readonly DirectProperty<DockableBase, bool> IsCollapsableProperty =
+        AvaloniaProperty.RegisterDirect<DockableBase, bool>(nameof(IsCollapsable), o => o.IsCollapsable, (o, v) => o.IsCollapsable = v, true);
+
+    /// <summary>
+    /// Defines the <see cref="Proportion"/> property.
+    /// </summary>
+    public static readonly DirectProperty<DockBase, double> ProportionProperty =
+        AvaloniaProperty.RegisterDirect<DockBase, double>(nameof(Proportion), o => o.Proportion, (o, v) => o.Proportion = v, double.NaN);
+
     /// <summary>
     /// Defines the <see cref="CanClose"/> property.
     /// </summary>
@@ -85,6 +103,9 @@ public abstract class DockableBase : StyledElement, IDockable
     private IDockable? _owner;
     private IDockable? _originalOwner;
     private IFactory? _factory;
+    private bool _isEmpty;
+    private bool _isCollapsable = true;
+    private double _proportion = double.NaN;
     private bool _canClose = true;
     private bool _canPin = true;
     private bool _canFloat = true;
@@ -153,6 +174,33 @@ public IFactory? Factory
         set => SetAndRaise(FactoryProperty, ref _factory, value);
     }
 
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    [JsonPropertyName("IsEmpty")]
+    public bool IsEmpty
+    {
+        get => _isEmpty;
+        set => SetAndRaise(IsEmptyProperty, ref _isEmpty, value);
+    }
+
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    [JsonPropertyName("IsCollapsable")]
+    public bool IsCollapsable
+    {
+        get => _isCollapsable;
+        set => SetAndRaise(IsCollapsableProperty, ref _isCollapsable, value);
+    }
+
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    [JsonPropertyName("Proportion")]
+    public double Proportion
+    {
+        get => _proportion;
+        set => SetAndRaise(ProportionProperty, ref _proportion, value);
+    }
+
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     [JsonPropertyName("CanClose")]
diff --git a/src/Dock.Model.Avalonia/Factory.cs b/src/Dock.Model.Avalonia/Factory.cs
index e28916f4..19317444 100644
--- a/src/Dock.Model.Avalonia/Factory.cs
+++ b/src/Dock.Model.Avalonia/Factory.cs
@@ -50,7 +50,13 @@ public Factory()
     public override IList<T> CreateList<T>(params T[] items) => new AvaloniaList<T>(items);
 
     /// <inheritdoc/>
-    public override IRootDock CreateRootDock() => new RootDock();
+    public override IRootDock CreateRootDock() => new RootDock
+    {
+        LeftPinnedDockables = CreateList<IDockable>(), 
+        RightPinnedDockables = CreateList<IDockable>(),
+        TopPinnedDockables = CreateList<IDockable>(),
+        BottomPinnedDockables = CreateList<IDockable>()
+    };
 
     /// <inheritdoc/>
     public override IProportionalDock CreateProportionalDock() => new ProportionalDock();
diff --git a/src/Dock.Model.Mvvm/Core/DockBase.cs b/src/Dock.Model.Mvvm/Core/DockBase.cs
index e14d9684..e93cb39e 100644
--- a/src/Dock.Model.Mvvm/Core/DockBase.cs
+++ b/src/Dock.Model.Mvvm/Core/DockBase.cs
@@ -18,12 +18,9 @@ public abstract class DockBase : DockableBase, IDock
     private IDockable? _activeDockable;
     private IDockable? _defaultDockable;
     private IDockable? _focusedDockable;
-    private double _proportion = double.NaN;
     private DockMode _dock = DockMode.Center;
-    private bool _isCollapsable = true;
     private int _openedDockablesCount = 0;
     private bool _isActive;
-    private bool _isEmpty;
 
     /// <summary>
     /// Initializes new instance of the <see cref="DockBase"/> class.
@@ -79,14 +76,6 @@ public IDockable? FocusedDockable
         }
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    public double Proportion
-    {
-        get => _proportion;
-        set => SetProperty(ref _proportion, value);
-    }
-
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     public DockMode Dock
@@ -103,22 +92,6 @@ public bool IsActive
         set => SetProperty(ref _isActive, value);
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    public bool IsEmpty
-    {
-        get => _isEmpty;
-        set => SetProperty(ref _isEmpty, value);
-    }
-
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    public bool IsCollapsable
-    {
-        get => _isCollapsable;
-        set => SetProperty(ref _isCollapsable, value);
-    }
-
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     public int OpenedDockablesCount
diff --git a/src/Dock.Model.Mvvm/Core/DockableBase.cs b/src/Dock.Model.Mvvm/Core/DockableBase.cs
index 2ac85521..afa54d28 100644
--- a/src/Dock.Model.Mvvm/Core/DockableBase.cs
+++ b/src/Dock.Model.Mvvm/Core/DockableBase.cs
@@ -18,6 +18,9 @@ public abstract class DockableBase : ObservableObject, IDockable
     private IDockable? _owner;
     private IDockable? _originalOwner;
     private IFactory? _factory;
+    private bool _isEmpty;
+    private bool _isCollapsable = true;
+    private double _proportion = double.NaN;
     private bool _canClose = true;
     private bool _canPin = true;
     private bool _canFloat = true;
@@ -78,6 +81,30 @@ public IFactory? Factory
         set => SetProperty(ref _factory, value);
     }
 
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    public bool IsEmpty
+    {
+        get => _isEmpty;
+        set => SetProperty(ref _isEmpty, value);
+    }
+
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    public bool IsCollapsable
+    {
+        get => _isCollapsable;
+        set => SetProperty(ref _isCollapsable, value);
+    }
+
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    public double Proportion
+    {
+        get => _proportion;
+        set => SetProperty(ref _proportion, value);
+    }
+
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     public bool CanClose
diff --git a/src/Dock.Model.Mvvm/Factory.cs b/src/Dock.Model.Mvvm/Factory.cs
index d1fdd51a..cab6cac3 100644
--- a/src/Dock.Model.Mvvm/Factory.cs
+++ b/src/Dock.Model.Mvvm/Factory.cs
@@ -43,7 +43,13 @@ public Factory()
     public override IList<T> CreateList<T>(params T[] items) => new ObservableCollection<T>(items);
 
     /// <inheritdoc/>
-    public override IRootDock CreateRootDock() => new RootDock();
+    public override IRootDock CreateRootDock() => new RootDock
+    {
+        LeftPinnedDockables = CreateList<IDockable>(), 
+        RightPinnedDockables = CreateList<IDockable>(),
+        TopPinnedDockables = CreateList<IDockable>(),
+        BottomPinnedDockables = CreateList<IDockable>()
+    };
 
     /// <inheritdoc/>
     public override IProportionalDock CreateProportionalDock() => new ProportionalDock();
diff --git a/src/Dock.Model.ReactiveUI/Core/DockBase.cs b/src/Dock.Model.ReactiveUI/Core/DockBase.cs
index 3be43ca0..92be7c26 100644
--- a/src/Dock.Model.ReactiveUI/Core/DockBase.cs
+++ b/src/Dock.Model.ReactiveUI/Core/DockBase.cs
@@ -18,11 +18,8 @@ public abstract class DockBase : DockableBase, IDock
     private IDockable? _activeDockable;
     private IDockable? _defaultDockable;
     private IDockable? _focusedDockable;
-    private double _proportion = double.NaN;
     private DockMode _dock = DockMode.Center;
-    private bool _isCollapsable = true;
     private bool _isActive;
-    private bool _isEmpty;
     private int _openedDockablesCount;
 
     /// <summary>
@@ -79,14 +76,6 @@ public IDockable? FocusedDockable
         }
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    public double Proportion
-    {
-        get => _proportion;
-        set => this.RaiseAndSetIfChanged(ref _proportion, value);
-    }
-
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     public DockMode Dock
@@ -103,14 +92,6 @@ public bool IsActive
         set => this.RaiseAndSetIfChanged(ref _isActive, value);
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    public bool IsEmpty
-    {
-        get => _isEmpty;
-        set => this.RaiseAndSetIfChanged(ref _isEmpty, value);
-    }
-
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     public int OpenedDockablesCount
@@ -119,14 +100,6 @@ public int OpenedDockablesCount
         set => this.RaiseAndSetIfChanged(ref _openedDockablesCount, value);
     }
 
-    /// <inheritdoc/>
-    [DataMember(IsRequired = false, EmitDefaultValue = true)]
-    public bool IsCollapsable
-    {
-        get => _isCollapsable;
-        set => this.RaiseAndSetIfChanged(ref _isCollapsable, value);
-    }
-
     /// <inheritdoc/>
     [IgnoreDataMember]
     public bool CanGoBack => _navigateAdapter.CanGoBack;
diff --git a/src/Dock.Model.ReactiveUI/Core/DockableBase.cs b/src/Dock.Model.ReactiveUI/Core/DockableBase.cs
index 5116948b..ec138b34 100644
--- a/src/Dock.Model.ReactiveUI/Core/DockableBase.cs
+++ b/src/Dock.Model.ReactiveUI/Core/DockableBase.cs
@@ -18,6 +18,9 @@ public abstract class DockableBase : ReactiveObject, IDockable
     private IDockable? _owner;
     private IDockable? _originalOwner;
     private IFactory? _factory;
+    private bool _isEmpty;
+    private bool _isCollapsable = true;
+    private double _proportion = double.NaN;
     private bool _canClose = true;
     private bool _canPin = true;
     private bool _canFloat = true;
@@ -78,6 +81,30 @@ public IFactory? Factory
         set => this.RaiseAndSetIfChanged(ref _factory, value);
     }
 
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    public bool IsEmpty
+    {
+        get => _isEmpty;
+        set => this.RaiseAndSetIfChanged(ref _isEmpty, value);
+    }
+
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    public bool IsCollapsable
+    {
+        get => _isCollapsable;
+        set => this.RaiseAndSetIfChanged(ref _isCollapsable, value);
+    }
+
+    /// <inheritdoc/>
+    [DataMember(IsRequired = false, EmitDefaultValue = true)]
+    public double Proportion
+    {
+        get => _proportion;
+        set => this.RaiseAndSetIfChanged(ref _proportion, value);
+    }
+
     /// <inheritdoc/>
     [DataMember(IsRequired = false, EmitDefaultValue = true)]
     public bool CanClose
diff --git a/src/Dock.Model.ReactiveUI/Factory.cs b/src/Dock.Model.ReactiveUI/Factory.cs
index fbd5120d..dbead5d2 100644
--- a/src/Dock.Model.ReactiveUI/Factory.cs
+++ b/src/Dock.Model.ReactiveUI/Factory.cs
@@ -43,7 +43,13 @@ public Factory()
     public override IList<T> CreateList<T>(params T[] items) => new ObservableCollection<T>(items);
 
     /// <inheritdoc/>
-    public override IRootDock CreateRootDock() => new RootDock();
+    public override IRootDock CreateRootDock() => new RootDock
+    {
+        LeftPinnedDockables = CreateList<IDockable>(), 
+        RightPinnedDockables = CreateList<IDockable>(),
+        TopPinnedDockables = CreateList<IDockable>(),
+        BottomPinnedDockables = CreateList<IDockable>()
+    };
 
     /// <inheritdoc/>
     public override IProportionalDock CreateProportionalDock() => new ProportionalDock();
@@ -65,4 +71,4 @@ public Factory()
 
     /// <inheritdoc/>
     public override IRootDock CreateLayout() => CreateRootDock();
-}
\ No newline at end of file
+}
diff --git a/src/Dock.Model/Core/IDock.cs b/src/Dock.Model/Core/IDock.cs
index 9901c7c0..e00f409b 100644
--- a/src/Dock.Model/Core/IDock.cs
+++ b/src/Dock.Model/Core/IDock.cs
@@ -28,11 +28,6 @@ public interface IDock : IDockable
     /// </summary>
     IDockable? FocusedDockable { get; set; }
 
-    /// <summary> 
-    /// Gets or sets splitter proportion. 
-    /// </summary> 
-    double Proportion { get; set; }
-
     /// <summary> 
     /// Gets or sets docking mode. 
     /// </summary> 
@@ -43,16 +38,6 @@ public interface IDock : IDockable
     /// </summary>
     bool IsActive { get; set; }
 
-    /// <summary>
-    /// Gets if the dockable is empty.
-    /// </summary>
-    bool IsEmpty { get; set; }
-
-    /// <summary>
-    /// Gets or sets if the Dock collapses when all its children are removed.
-    /// </summary>
-    bool IsCollapsable { get; set; }
-
     /// <summary>
     /// Gets the number of currently opened and visible dockables
     /// </summary>
diff --git a/src/Dock.Model/Core/IDockable.cs b/src/Dock.Model/Core/IDockable.cs
index 410036e3..f7b689c8 100644
--- a/src/Dock.Model/Core/IDockable.cs
+++ b/src/Dock.Model/Core/IDockable.cs
@@ -38,6 +38,21 @@ public interface IDockable : IControlRecyclingIdProvider
     /// </summary>
     IFactory? Factory { get; set; }
 
+    /// <summary>
+    /// Gets if the dockable is empty.
+    /// </summary>
+    bool IsEmpty { get; set; }
+
+    /// <summary>
+    /// Gets or sets if the dockable collapses when all its children are removed.
+    /// </summary>
+    bool IsCollapsable { get; set; }
+
+    /// <summary> 
+    /// Gets or sets splitter proportion. 
+    /// </summary> 
+    double Proportion { get; set; }
+
     /// <summary>
     /// Gets or sets if the dockable can be closed.
     /// </summary>