Index: binaries/data/mods/public/simulation/components/Upgrade.js
===================================================================
--- binaries/data/mods/public/simulation/components/Upgrade.js
+++ binaries/data/mods/public/simulation/components/Upgrade.js
@@ -47,6 +47,9 @@
 						"</choice>" +
 					"</element>" +
 				"</optional>" +
+				"<optional>" +
+					ModificationsSchema +
+				"</optional>" +
 				"<optional>" +
 					"<element name='CheckPlacementRestrictions' a:help='Upgrading will check for placement restrictions (nb:GUI only)'><empty/></element>" +
 				"</optional>" +
@@ -257,6 +260,14 @@
 	// Prevent cheating
 	this.ChangeUpgradedEntityCount(1);
 
+	if (this.template[this.upgradeTemplates[template]].Modifiers)
+	{
+		let cmpModifiersManager = Engine.QueryInterface(SYSTEM_ENTITY, IID_ModifiersManager);
+		cmpModifiersManager.AddModifiers("upgrade_" + this.entity,
+			DeriveModificationsFromXMLTemplate(this.template[this.upgradeTemplates[template]].Modifiers),
+			this.entity);
+	}
+
 	if (this.GetUpgradeTime(template) !== 0)
 	{
 		let cmpTimer = Engine.QueryInterface(SYSTEM_ENTITY, IID_Timer);
@@ -273,6 +284,12 @@
 	if (!this.IsUpgrading())
 		return;
 
+	if (this.template[this.upgradeTemplates[this.upgrading]].Modifiers)
+	{
+		let cmpModifiersManager = Engine.QueryInterface(SYSTEM_ENTITY, IID_ModifiersManager);
+		cmpModifiersManager.RemoveAllModifiers("upgrade_" + this.entity, this.entity);
+	}
+
 	let cmpPlayer = QueryPlayerIDInterface(owner, IID_Player);
 	if (cmpPlayer)
 		cmpPlayer.AddResources(this.expendedResources);
Index: binaries/data/mods/public/simulation/templates/structures/cart/house.xml
===================================================================
--- binaries/data/mods/public/simulation/templates/structures/cart/house.xml
+++ binaries/data/mods/public/simulation/templates/structures/cart/house.xml
@@ -10,6 +10,23 @@
   <Obstruction>
     <Static width="13.0" depth="13.0"/>
   </Obstruction>
+  <Upgrade>
+    <Appt>
+      <Entity>structures/cart/apartment</Entity>
+      <Cost>
+        <wood>40</wood>
+        <stone>40</stone>
+      </Cost>
+      <Time>60</Time>
+      <Modifiers>
+        <pop>
+          <Add>-3</Add>
+          <Affects datatype="tokens">Structure</Affects>
+          <Paths datatype="tokens">Population/Bonus</Paths>
+        </pop>
+      </Modifiers>
+    </Appt>
+  </Upgrade>
   <VisualActor>
     <FoundationActor>structures/carthaginians/fndn_house.xml</FoundationActor>
     <Actor>structures/carthaginians/house.xml</Actor>