diff --git a/VectoCore/VectoCore/Resources/XSD/VectoDeclarationDefinitions.2.8_Stage.xsd b/VectoCore/VectoCore/Resources/XSD/VectoDeclarationDefinitions.2.8_Stage.xsd
index e6ca0c0591fab894472daacadff81806666aebbf..f271776933f2fb024bc792951d4e85e5af4de647 100644
--- a/VectoCore/VectoCore/Resources/XSD/VectoDeclarationDefinitions.2.8_Stage.xsd
+++ b/VectoCore/VectoCore/Resources/XSD/VectoDeclarationDefinitions.2.8_Stage.xsd
@@ -436,6 +436,7 @@
 			<xs:enumeration value="heating"/>
 			<xs:enumeration value="heating and cooling"/>
 			<xs:enumeration value="cooling"/>
+			<xs:enumeration value="N.A."/>
 		</xs:restriction>
 	</xs:simpleType>
 	<xs:simpleType name="HVACHeatPumpType">