diff --git a/ucalc/Annotations.cs b/ucalc/Annotations.cs
index 84abdc0..e8ef5b5 100644
--- a/ucalc/Annotations.cs
+++ b/ucalc/Annotations.cs
@@ -32,7 +32,7 @@ using System;
 // ReSharper disable MemberCanBeProtected.Global
 // ReSharper disable InconsistentNaming
 
-namespace ucalc.Annotations
+namespace UCalc.Annotations
 {
     /// <summary>
     /// Indicates that the value of the marked element could be <c>null</c> sometimes,
diff --git a/ucalc/BillingWindow.xaml.cs b/ucalc/BillingWindow.xaml.cs
index f645e51..a95181a 100644
--- a/ucalc/BillingWindow.xaml.cs
+++ b/ucalc/BillingWindow.xaml.cs
@@ -48,6 +48,7 @@ namespace UCalc
         {
             var page = (HousePage) ((Frame) sender).Content;
             page.Model = Model.HouseModel;
+            page.ParentWindow = this;
         }
     }
 }
\ No newline at end of file
diff --git a/ucalc/Controls/ErrorIcon.xaml.cs b/ucalc/Controls/ErrorIcon.xaml.cs
index 31bc7b5..de95dc7 100644
--- a/ucalc/Controls/ErrorIcon.xaml.cs
+++ b/ucalc/Controls/ErrorIcon.xaml.cs
@@ -4,7 +4,7 @@ using System.ComponentModel;
 using System.Runtime.CompilerServices;
 using System.Windows;
 using System.Windows.Data;
-using ucalc.Annotations;
+using UCalc.Annotations;
 
 namespace UCalc.Controls
 {
diff --git a/ucalc/Controls/SectionHeader.xaml b/ucalc/Controls/SectionHeader.xaml
index 9922a59..fa718c5 100644
--- a/ucalc/Controls/SectionHeader.xaml
+++ b/ucalc/Controls/SectionHeader.xaml
@@ -7,7 +7,7 @@
              xmlns:controls="clr-namespace:UCalc.Controls"
              mc:Ignorable="d">
 
-    <Grid Margin="10, 0, 5, 0">
+    <Grid Margin="10, 0, 10, 0">
         <Grid.ColumnDefinitions>
             <ColumnDefinition Width="*" />
             <ColumnDefinition Width="auto" />
diff --git a/ucalc/FlatWindow.xaml b/ucalc/FlatWindow.xaml
new file mode 100644
index 0000000..a047440
--- /dev/null
+++ b/ucalc/FlatWindow.xaml
@@ -0,0 +1,74 @@
+<Window x:Class="UCalc.FlatWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:local="clr-namespace:UCalc"
+        xmlns:controls="clr-namespace:UCalc.Controls"
+        mc:Ignorable="d"
+        Title="Wohnung bearbeiten"
+        Width="500"
+        SizeToContent="Height"
+        MinWidth="400"
+        MinHeight="190"
+        WindowStartupLocation="CenterOwner"
+        ShowInTaskbar="False">
+
+    <DockPanel>
+        <StackPanel DockPanel.Dock="Bottom">
+            <Separator Margin="0, 12, 0, 0"
+                       Background="{x:Static local:Constants.SubMainColor}"/>
+
+            <DockPanel LastChildFill="False">
+                <Button DockPanel.Dock="Right"
+                        MinWidth="100"
+                        MinHeight="24"
+                        Margin="12"
+                        Content="OK"
+                        Click="OnOkClick"/>
+            </DockPanel>
+        </StackPanel>
+
+        <ScrollViewer HorizontalScrollBarVisibility="Disabled"
+                      VerticalScrollBarVisibility="Auto">
+            <StackPanel>
+                <controls:SectionHeader Header="Allgemeine Informationen" />
+
+                <DockPanel Margin="12, 8, 12, 0">
+                    <Label DockPanel.Dock="Left"
+                           Content="Name:"
+                           Width="180"
+                           Foreground="{x:Static local:Constants.SubMainColor}" />
+
+                    <controls:ErrorIcon Margin="12, 0, 0, 0"
+                                        DockPanel.Dock="Right"
+                                        VerticalAlignment="Center"
+                                        Errors="{Binding Path=Model.Name.Errors, RelativeSource={RelativeSource AncestorType=local:FlatWindow}}" />
+
+                    <TextBox
+                        VerticalAlignment="Center"
+                        MinHeight="22"
+                        Text="{Binding Path=Model.Name.Value, RelativeSource={RelativeSource AncestorType=local:FlatWindow}, UpdateSourceTrigger=PropertyChanged}" />
+                </DockPanel>
+
+                <DockPanel Margin="12, 8, 12, 0">
+                    <Label DockPanel.Dock="Left"
+                           Content="Größe in m²:"
+                           Width="180"
+                           Foreground="{x:Static local:Constants.SubMainColor}" />
+
+                    <controls:ErrorIcon Margin="12, 0, 0, 0"
+                                        DockPanel.Dock="Right"
+                                        VerticalAlignment="Center"
+                                        Errors="{Binding Path=Model.Size.Errors, RelativeSource={RelativeSource AncestorType=local:FlatWindow}}" />
+
+                    <TextBox
+                        VerticalAlignment="Center"
+                        MinHeight="22"
+                        Text="{Binding Path=Model.Size.Value, RelativeSource={RelativeSource AncestorType=local:FlatWindow}, UpdateSourceTrigger=PropertyChanged}" />
+                </DockPanel>
+            </StackPanel>
+        </ScrollViewer>
+    </DockPanel>
+
+</Window>
\ No newline at end of file
diff --git a/ucalc/FlatWindow.xaml.cs b/ucalc/FlatWindow.xaml.cs
new file mode 100644
index 0000000..440ddad
--- /dev/null
+++ b/ucalc/FlatWindow.xaml.cs
@@ -0,0 +1,21 @@
+using System.Windows;
+using UCalc.Models;
+
+namespace UCalc
+{
+    public partial class FlatWindow
+    {
+        public FlatModel Model { get; }
+
+        public FlatWindow(FlatModel model)
+        {
+            Model = model;
+            InitializeComponent();
+        }
+
+        private void OnOkClick(object sender, RoutedEventArgs e)
+        {
+            Close();
+        }
+    }
+}
\ No newline at end of file
diff --git a/ucalc/Models/Model.cs b/ucalc/Models/Model.cs
index 27dbc2a..c280799 100644
--- a/ucalc/Models/Model.cs
+++ b/ucalc/Models/Model.cs
@@ -4,7 +4,7 @@ using System.Collections.ObjectModel;
 using System.ComponentModel;
 using System.Linq;
 using System.Runtime.CompilerServices;
-using ucalc.Annotations;
+using UCalc.Annotations;
 
 namespace UCalc.Models
 {
@@ -133,6 +133,8 @@ namespace UCalc.Models
 
                 _modified = true;
                 _value = value;
+
+                OnPropertyChanged("Value");
             }
         }
 
diff --git a/ucalc/NewWindow.xaml b/ucalc/NewWindow.xaml
index dac42d6..a389baf 100644
--- a/ucalc/NewWindow.xaml
+++ b/ucalc/NewWindow.xaml
@@ -12,6 +12,8 @@
         WindowStartupLocation="CenterOwner"
         PreviewMouseUp="OnPreviewMouseUp">
 
+    <!-- TODO: Wrap in scroll to handle small screens! -->
+    
     <StackPanel Margin="12">
 
         <Label Content="Geben Sie den Zeitraum ein, für den die neue Abrechnung gelten soll."
@@ -53,8 +55,8 @@
                     Content="..."
                     Margin="6, 0, 0, 0"
                     Width="30"
-                    IsEnabled="{Binding IsChecked, ElementName=ReuseDataCheckBox}" 
-                    Click="OnBrowseClick"/>
+                    IsEnabled="{Binding IsChecked, ElementName=ReuseDataCheckBox}"
+                    Click="OnBrowseClick" />
 
             <ComboBox Name="ReuseDataComboBox"
                       IsEnabled="{Binding IsChecked, ElementName=ReuseDataCheckBox}"
@@ -67,14 +69,15 @@
             </ComboBox>
         </DockPanel>
 
-        <Separator Margin="0, 0, 0, 12" />
+        <Separator Margin="0, 0, 0, 12"
+                   Background="{x:Static local:Constants.SubMainColor}" />
 
         <DockPanel LastChildFill="False">
             <Button DockPanel.Dock="Right"
                     MinWidth="100"
                     MinHeight="24"
                     Content="Erstellen"
-                    Click="OnCreateClick"/>
+                    Click="OnCreateClick" />
         </DockPanel>
     </StackPanel>
 
diff --git a/ucalc/Pages/HousePage.xaml b/ucalc/Pages/HousePage.xaml
index cd21e39..685c7d0 100644
--- a/ucalc/Pages/HousePage.xaml
+++ b/ucalc/Pages/HousePage.xaml
@@ -16,7 +16,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Straße:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -33,7 +33,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Hausnummer:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -50,7 +50,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Stadt:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -67,7 +67,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="PLZ:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -140,7 +140,8 @@
                             </controls:HighlightButton>
 
                             <controls:HighlightButton HighlightForeground="{x:Static local:Constants.SubMainColor}"
-                                                      HighlightBackground="{x:Static local:Constants.MainColor}">
+                                                      HighlightBackground="{x:Static local:Constants.MainColor}"
+                                                      Click="OnFlatEditClick">
 
                                 <controls:ErrorIcon Errors="{Binding Errors}"
                                                     DockPanel.Dock="Left"
diff --git a/ucalc/Pages/HousePage.xaml.cs b/ucalc/Pages/HousePage.xaml.cs
index 91ba23c..026de8b 100644
--- a/ucalc/Pages/HousePage.xaml.cs
+++ b/ucalc/Pages/HousePage.xaml.cs
@@ -6,6 +6,7 @@ namespace UCalc.Pages
 {
     public partial class HousePage
     {
+        public Window ParentWindow { get; set; }
         public HouseModel Model { get; set; }
 
         public HousePage()
@@ -28,5 +29,12 @@ namespace UCalc.Pages
                 Model.RemoveFlat(flatModel);
             }
         }
+
+        private void OnFlatEditClick(object sender, RoutedEventArgs e)
+        {
+            var flatModel = (FlatModel) ((HighlightButton) sender).DataContext;
+
+            new FlatWindow(flatModel) {Owner = ParentWindow}.ShowDialog();
+        }
     }
 }
\ No newline at end of file
diff --git a/ucalc/Pages/LandlordPage.xaml b/ucalc/Pages/LandlordPage.xaml
index a6b06d2..b3126cb 100644
--- a/ucalc/Pages/LandlordPage.xaml
+++ b/ucalc/Pages/LandlordPage.xaml
@@ -16,7 +16,7 @@
             <DockPanel Margin="12, 12, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Anrede:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <ComboBox Margin="0, 0, 28, 0" /> <!-- TODO -->
@@ -25,7 +25,7 @@
             <DockPanel Margin="12, 12, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Name:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -42,7 +42,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Telefonnummer:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -59,7 +59,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Email Adresse:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -79,7 +79,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Straße:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -96,7 +96,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Hausnummer:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -113,7 +113,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="Stadt:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -130,7 +130,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="PLZ:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -150,7 +150,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="IBAN:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -167,7 +167,7 @@
             <DockPanel Margin="12, 8, 12, 0">
                 <Label DockPanel.Dock="Left"
                        Content="BIC:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
@@ -184,7 +184,7 @@
             <DockPanel Margin="12, 8, 12, 12">
                 <Label DockPanel.Dock="Left"
                        Content="Name der Bank:"
-                       Width="200"
+                       Width="180"
                        Foreground="{x:Static local:Constants.SubMainColor}" />
 
                 <controls:ErrorIcon Margin="12, 0, 0, 0"
diff --git a/ucalc/ucalc.csproj b/ucalc/ucalc.csproj
index ce35e78..63f2542 100644
--- a/ucalc/ucalc.csproj
+++ b/ucalc/ucalc.csproj
@@ -37,6 +37,9 @@
         <Page Update="Controls\SectionHeader.xaml">
             <Generator></Generator>
         </Page>
+        <Page Update="FlatWindow.xaml">
+            <Generator></Generator>
+        </Page>
     </ItemGroup>
 
     <ItemGroup>
@@ -70,6 +73,9 @@
         <Compile Update="Controls\SectionHeader.xaml.cs">
             <DependentUpon>SectionHeader.xaml</DependentUpon>
         </Compile>
+        <Compile Update="FlatWindow.xaml.cs">
+            <DependentUpon>FlatWindow.xaml</DependentUpon>
+        </Compile>
     </ItemGroup>
 
 </Project>
\ No newline at end of file