diff --git a/de.hftstuttgart.buildingphysics.edit/src/de/hftstuttgart/buildingphysics/provider/WindowTypeItemProvider.java b/de.hftstuttgart.buildingphysics.edit/src/de/hftstuttgart/buildingphysics/provider/WindowTypeItemProvider.java
index fa4c6f62ebdeb3d53046843caac2b3f0dafe5974..1f0588a6dcaedd6c67fe7d99264d6cfe56fcca35 100644
--- a/de.hftstuttgart.buildingphysics.edit/src/de/hftstuttgart/buildingphysics/provider/WindowTypeItemProvider.java
+++ b/de.hftstuttgart.buildingphysics.edit/src/de/hftstuttgart/buildingphysics/provider/WindowTypeItemProvider.java
@@ -162,7 +162,7 @@ public class WindowTypeItemProvider extends ItemProviderAdapter implements IEdit
 						getString("_UI_PropertyDescriptor_description", "_UI_WindowType_frameRatio_feature",
 								"_UI_WindowType_type"),
 						BuildingPhysicsPackage.Literals.WINDOW_TYPE__FRAME_RATIO, true, false, false,
-						ItemPropertyDescriptor.REAL_VALUE_IMAGE, null, null));
+						ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
 	}
 
 	/**
diff --git a/de.hftstuttgart.buildingphysics.viewmodel/META-INF/MANIFEST.MF b/de.hftstuttgart.buildingphysics.viewmodel/META-INF/MANIFEST.MF
index 4d6ac4eb1bd6ccc32b4cea40be69b71214c45c78..3f1d066661f1909e0276a23e86f114f848b809ae 100644
--- a/de.hftstuttgart.buildingphysics.viewmodel/META-INF/MANIFEST.MF
+++ b/de.hftstuttgart.buildingphysics.viewmodel/META-INF/MANIFEST.MF
@@ -5,5 +5,8 @@ Bundle-SymbolicName: de.hftstuttgart.buildingphysics.viewmodel;singleton:=true
 Bundle-Version: 1.0.0.qualifier
 Require-Bundle: org.eclipse.emf.ecp.view.model.provider.xmi,
  org.eclipse.emf.ecp.view.treemasterdetail.model,
- org.eclipse.emf.ecp.view.treemasterdetail.ui.swt
+ org.eclipse.emf.ecp.view.treemasterdetail.ui.swt,
+ de.hftstuttgart.cityunits.model;bundle-version="1.0.2",
+ de.hftstuttgart.cityunits.model.edit;bundle-version="1.0.2",
+ de.hftstuttgart.cityunits.ui.renderer;bundle-version="1.0.2"
 Bundle-RequiredExecutionEnvironment: JavaSE-15
diff --git a/de.hftstuttgart.buildingphysics.viewmodel/viewmodels/WindowType.view b/de.hftstuttgart.buildingphysics.viewmodel/viewmodels/WindowType.view
index 8bc45cf627907b6a0bca3f1d8b10b9df555bad4e..90ee7e06d437cf2dc9eb5b4f320d3b62cb82bed2 100644
--- a/de.hftstuttgart.buildingphysics.viewmodel/viewmodels/WindowType.view
+++ b/de.hftstuttgart.buildingphysics.viewmodel/viewmodels/WindowType.view
@@ -26,8 +26,8 @@
       <domainModelEFeature xsi:type="ecore:EAttribute" href="http://www.hftstuttgart.de/buildingphysics#//WindowType/glazingNumber"/>
     </domainModelReference>
   </children>
-  <children xsi:type="org.eclipse.emf.ecp.view.model:Control" xmi:id="_7hPBWq21Eeup29SeaUMpQQ" name="Control frameRatio">
-    <domainModelReference xsi:type="org.eclipse.emf.ecp.view.model:FeaturePathDomainModelReference" xmi:id="_7hPBW621Eeup29SeaUMpQQ">
+  <children xsi:type="org.eclipse.emf.ecp.view.model:Control" xmi:id="_7qjMwMRbEeu2E-0upv8JGw" name="Control frameRatio">
+    <domainModelReference xsi:type="org.eclipse.emf.ecp.view.model:FeaturePathDomainModelReference" xmi:id="_7qjMwcRbEeu2E-0upv8JGw">
       <domainModelEFeature xsi:type="ecore:EAttribute" href="http://www.hftstuttgart.de/buildingphysics#//WindowType/frameRatio"/>
     </domainModelReference>
   </children>
diff --git a/de.hftstuttgart.buildingphysics/model/buildingphysics.aird b/de.hftstuttgart.buildingphysics/model/buildingphysics.aird
index baf8d4881621443f6a4cb9a19f8c46e709786087..6daeea68fe5537a19011cb414210619cf1bd60cd 100644
--- a/de.hftstuttgart.buildingphysics/model/buildingphysics.aird
+++ b/de.hftstuttgart.buildingphysics/model/buildingphysics.aird
@@ -9,7 +9,7 @@
     <semanticResources>../catalogs/2020%20German%20Buildings%20IWU.xmi</semanticResources>
     <ownedViews xmi:type="viewpoint:DView" uid="_nfHygB3ZEeuNsK3dZmTkbQ">
       <viewpoint xmi:type="description:Viewpoint" href="platform:/plugin/org.eclipse.emf.ecoretools.design/description/ecore.odesign#//@ownedViewpoints[name='Design']"/>
-      <ownedRepresentationDescriptors xmi:type="viewpoint:DRepresentationDescriptor" uid="_JKPtIZUqEeudooziRGqkJA" name="Buildingphysics Class Diagram" repPath="#_JKN38JUqEeudooziRGqkJA" changeId="938342a3-345d-40bf-9732-a7d354ccd5c3">
+      <ownedRepresentationDescriptors xmi:type="viewpoint:DRepresentationDescriptor" uid="_JKPtIZUqEeudooziRGqkJA" name="Buildingphysics Class Diagram" repPath="#_JKN38JUqEeudooziRGqkJA" changeId="83985646-3cd2-4c87-8200-0e1db764f151">
         <description xmi:type="description_1:DiagramDescription" href="platform:/plugin/org.eclipse.emf.ecoretools.design/description/ecore.odesign#//@ownedViewpoints[name='Design']/@ownedRepresentations[name='Entities']"/>
         <target xmi:type="ecore:EPackage" href="buildingphysics.ecore#/"/>
       </ownedRepresentationDescriptors>
@@ -478,7 +478,7 @@
         </ownedStyle>
         <actualMapping xmi:type="description_1:NodeMapping" href="platform:/plugin/org.eclipse.emf.ecoretools.design/description/ecore.odesign#//@ownedViewpoints[name='Design']/@ownedRepresentations[name='Entities']/@defaultLayer/@containerMappings[name='EC%20EClass']/@subNodeMappings[name='EC%20EAttribute']"/>
       </ownedElements>
-      <ownedElements xmi:type="diagram:DNodeListElement" uid="_J2rVU5UqEeudooziRGqkJA" name="frameRatio : EDouble = 0.0" tooltipText="">
+      <ownedElements xmi:type="diagram:DNodeListElement" uid="_J2rVU5UqEeudooziRGqkJA" name="frameRatio : Fraction" tooltipText="">
         <target xmi:type="ecore:EAttribute" href="buildingphysics.ecore#//WindowType/frameRatio"/>
         <semanticElements xmi:type="ecore:EAttribute" href="buildingphysics.ecore#//WindowType/frameRatio"/>
         <ownedStyle xmi:type="diagram:BundledImage" uid="_J2rVVJUqEeudooziRGqkJA" labelAlignment="LEFT" description="_J2qHNJUqEeudooziRGqkJA">
diff --git a/de.hftstuttgart.buildingphysics/model/buildingphysics.ecore b/de.hftstuttgart.buildingphysics/model/buildingphysics.ecore
index 40f4408469af0608e7b5116a11b460f1901e6dc7..f720a93326376e0a3b29625ec8748254dc7aa955 100644
--- a/de.hftstuttgart.buildingphysics/model/buildingphysics.ecore
+++ b/de.hftstuttgart.buildingphysics/model/buildingphysics.ecore
@@ -29,7 +29,7 @@
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="glazingNumber" lowerBound="1"
         eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EInt" defaultValueLiteral="1"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="frameRatio" lowerBound="1"
-        eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EDouble">
+        eType="ecore:EDataType ../../de.hftstuttgart.cityunits.model/model/Quantities.ecore#//Fraction">
       <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
         <details key="documentation" value="fraction between 0.0 and 1.0"/>
       </eAnnotations>
diff --git a/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/WindowType.java b/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/WindowType.java
index d9558503ed9fece049116d2a6ff113fcb4d9c98b..ab1408c1beeca51290481d4c8425ddaefd8764bd 100644
--- a/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/WindowType.java
+++ b/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/WindowType.java
@@ -157,12 +157,12 @@ public interface WindowType extends EObject {
 	 * fraction between 0.0 and 1.0
 	 * <!-- end-model-doc -->
 	 * @return the value of the '<em>Frame Ratio</em>' attribute.
-	 * @see #setFrameRatio(double)
+	 * @see #setFrameRatio(Double)
 	 * @see de.hftstuttgart.buildingphysics.BuildingPhysicsPackage#getWindowType_FrameRatio()
-	 * @model required="true"
+	 * @model dataType="de.hftstuttgart.cityunits.model.quantities.Fraction" required="true"
 	 * @generated
 	 */
-	double getFrameRatio();
+	Double getFrameRatio();
 
 	/**
 	 * Sets the value of the '{@link de.hftstuttgart.buildingphysics.WindowType#getFrameRatio <em>Frame Ratio</em>}' attribute.
@@ -172,7 +172,7 @@ public interface WindowType extends EObject {
 	 * @see #getFrameRatio()
 	 * @generated
 	 */
-	void setFrameRatio(double value);
+	void setFrameRatio(Double value);
 
 	/**
 	 * Returns the value of the '<em><b>Embodied Energy</b></em>' attribute.
diff --git a/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/BuildingPhysicsPackageImpl.java b/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/BuildingPhysicsPackageImpl.java
index 96af7a94ebdb1577af013499d2917fa66fefebb0..e62b95fe82a638031d60c3825f17e88effb18420 100644
--- a/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/BuildingPhysicsPackageImpl.java
+++ b/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/BuildingPhysicsPackageImpl.java
@@ -790,7 +790,7 @@ public class BuildingPhysicsPackageImpl extends EPackageImpl implements Building
 		initEAttribute(getWindowType_GlazingNumber(), ecorePackage.getEInt(), "glazingNumber", "1", 1, 1,
 				WindowType.class, !IS_TRANSIENT, !IS_VOLATILE, IS_CHANGEABLE, !IS_UNSETTABLE, !IS_ID, IS_UNIQUE,
 				!IS_DERIVED, IS_ORDERED);
-		initEAttribute(getWindowType_FrameRatio(), ecorePackage.getEDouble(), "frameRatio", null, 1, 1,
+		initEAttribute(getWindowType_FrameRatio(), theQuantitiesPackage.getFraction(), "frameRatio", null, 1, 1,
 				WindowType.class, !IS_TRANSIENT, !IS_VOLATILE, IS_CHANGEABLE, !IS_UNSETTABLE, !IS_ID, IS_UNIQUE,
 				!IS_DERIVED, IS_ORDERED);
 		initEAttribute(getWindowType_EmbodiedEnergy(), theQuantitiesPackage.getQuantityDouble(), "embodiedEnergy",
diff --git a/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/WindowTypeImpl.java b/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/WindowTypeImpl.java
index 02730ff7859d803142282e95a2d351018c63f40f..256382b5c685173554bcbbbe26846479904f6358 100644
--- a/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/WindowTypeImpl.java
+++ b/de.hftstuttgart.buildingphysics/src/de/hftstuttgart/buildingphysics/impl/WindowTypeImpl.java
@@ -151,7 +151,7 @@ public class WindowTypeImpl extends MinimalEObjectImpl.Container implements Wind
 	 * @generated
 	 * @ordered
 	 */
-	protected static final double FRAME_RATIO_EDEFAULT = 0.0;
+	protected static final Double FRAME_RATIO_EDEFAULT = null;
 
 	/**
 	 * The cached value of the '{@link #getFrameRatio() <em>Frame Ratio</em>}' attribute.
@@ -161,7 +161,7 @@ public class WindowTypeImpl extends MinimalEObjectImpl.Container implements Wind
 	 * @generated
 	 * @ordered
 	 */
-	protected double frameRatio = FRAME_RATIO_EDEFAULT;
+	protected Double frameRatio = FRAME_RATIO_EDEFAULT;
 
 	/**
 	 * The default value of the '{@link #getEmbodiedEnergy() <em>Embodied Energy</em>}' attribute.
@@ -432,7 +432,7 @@ public class WindowTypeImpl extends MinimalEObjectImpl.Container implements Wind
 	 * @generated
 	 */
 	@Override
-	public double getFrameRatio() {
+	public Double getFrameRatio() {
 		return frameRatio;
 	}
 
@@ -442,8 +442,8 @@ public class WindowTypeImpl extends MinimalEObjectImpl.Container implements Wind
 	 * @generated
 	 */
 	@Override
-	public void setFrameRatio(double newFrameRatio) {
-		double oldFrameRatio = frameRatio;
+	public void setFrameRatio(Double newFrameRatio) {
+		Double oldFrameRatio = frameRatio;
 		frameRatio = newFrameRatio;
 		if (eNotificationRequired())
 			eNotify(new ENotificationImpl(this, Notification.SET, BuildingPhysicsPackage.WINDOW_TYPE__FRAME_RATIO,
@@ -748,7 +748,7 @@ public class WindowTypeImpl extends MinimalEObjectImpl.Container implements Wind
 		case BuildingPhysicsPackage.WINDOW_TYPE__GLAZING_NUMBER:
 			return glazingNumber != GLAZING_NUMBER_EDEFAULT;
 		case BuildingPhysicsPackage.WINDOW_TYPE__FRAME_RATIO:
-			return frameRatio != FRAME_RATIO_EDEFAULT;
+			return FRAME_RATIO_EDEFAULT == null ? frameRatio != null : !FRAME_RATIO_EDEFAULT.equals(frameRatio);
 		case BuildingPhysicsPackage.WINDOW_TYPE__EMBODIED_ENERGY:
 			return EMBODIED_ENERGY_EDEFAULT == null ? embodiedEnergy != null
 					: !EMBODIED_ENERGY_EDEFAULT.equals(embodiedEnergy);