diff --git a/Detector/DetInterface/CMakeLists.txt b/Detector/DetInterface/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..0467315516667b8ae5ba630ab34301d072eeca84
--- /dev/null
+++ b/Detector/DetInterface/CMakeLists.txt
@@ -0,0 +1,8 @@
+################################################################################
+# Package: DetInterface
+################################################################################
+gaudi_subdir(DetInterface v1r0)
+
+gaudi_depends_on_subdirs(GaudiKernel)
+
+gaudi_install_headers(DetInterface)
diff --git a/Detector/DetInterface/DetInterface/IGeoSvc.h b/Detector/DetInterface/DetInterface/IGeoSvc.h
new file mode 100644
index 0000000000000000000000000000000000000000..02db1bfae15a1b252f9c7439590ddbc24745de12
--- /dev/null
+++ b/Detector/DetInterface/DetInterface/IGeoSvc.h
@@ -0,0 +1,35 @@
+//
+//  IGeoSvc.h
+//
+//  Based on FCCSW.
+//  Created by Julia Hrdinka on 30/03/15.
+//
+//
+
+#ifndef IGEOSVC_H
+#define IGEOSVC_H
+
+#include "GaudiKernel/IService.h"
+
+namespace dd4hep {
+class Detector;
+class DetElement;
+}
+
+class G4VUserDetectorConstruction;
+
+class GAUDI_API IGeoSvc : virtual public IService {
+
+public:
+  /// InterfaceID
+  DeclareInterfaceID(IGeoSvc, 1, 0);
+  // receive DD4hep Geometry
+  virtual dd4hep::DetElement getDD4HepGeo() = 0;
+  virtual dd4hep::Detector* lcdd() = 0;
+  // receive Geant4 Geometry
+  virtual G4VUserDetectorConstruction* getGeant4Geo() = 0;
+
+  virtual ~IGeoSvc() {}
+};
+
+#endif  // IGEOSVC_H