diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 563db5dd14..d600baa5b8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -62,7 +62,7 @@ jobs:
                -DPYTHON_INCLUDE_DIR:PATH=/usr/include/python3.8 \
                -DPYTHON_LIBRARY:FILEPATH=/usr/lib/x86_64-linux-gnu/libpython3.8.so \
                -DCOLLADA_SUPPORT=Off \
-               "-DSCHEMA_VERSIONS=2x3;4" \
+               "-DSCHEMA_VERSIONS=2x3;4;4x3" \
                -DGLTF_SUPPORT=On \
                -DJSON_INCLUDE_DIR=/usr/include \
                -DCGAL_INCLUDE_DIR=/usr/include \
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 514c3acdb6..b51c04bff9 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -590,13 +590,16 @@ function(files_for_ifc_version IFC_VERSION RESULT_NAME)
 endfunction()
 
 if(NOT SCHEMA_VERSIONS)
-    set(SCHEMA_VERSIONS "2x3" "4" "4x1" "4x2" "4x3_rc1" "4x3_rc2" "4x3_rc3" "4x3_rc4")
+    set(SCHEMA_VERSIONS "2x3" "4" "4x1" "4x2" "4x3_rc1" "4x3_rc2" "4x3_rc3" "4x3_rc4", "4x3")
 endif()
 
 foreach(s ${SCHEMA_VERSIONS})
 	add_definitions(-DHAS_SCHEMA_${s})
 endforeach()
 
+string(REPLACE ";" ")(" schema_version_seq "(${SCHEMA_VERSIONS})")
+ADD_DEFINITIONS(-DSCHEMA_SEQ=${schema_version_seq})
+
 if(COMPILE_SCHEMA)
 	# @todo, this appears to be untested at the moment
 
diff --git a/src/ifcgeom_schema_agnostic/IteratorImplementation.cpp b/src/ifcgeom_schema_agnostic/IteratorImplementation.cpp
index 1bea4fc73d..2333ade00f 100644
--- a/src/ifcgeom_schema_agnostic/IteratorImplementation.cpp
+++ b/src/ifcgeom_schema_agnostic/IteratorImplementation.cpp
@@ -1,55 +1,30 @@
 #include "IteratorImplementation.h"
 
+#include <boost/preprocessor/stringize.hpp>
+#include <boost/preprocessor/seq/for_each.hpp>
 #include <boost/algorithm/string/case_conv.hpp>
 
+// Declares the schema-based external iterator initialization routines:
+// - extern void init_IteratorImplementation_Ifc2x3(IteratorFactoryImplementation*);
+// - ...
+#define EXTERNAL_DEFS(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(extern void init_IteratorImplementation_, elem), (IteratorFactoryImplementation*);)
+
+// Declares the schema-based external iterator initialization routines:
+// - init_IteratorImplementation_Ifc2x3(this);
+// - ...
+#define CALL_DEFS(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(init_IteratorImplementation_, elem), (this);)
+
 IFC_GEOM_API IteratorFactoryImplementation& iterator_implementations() {
 	static IteratorFactoryImplementation impl;
 	return impl;
 }
 
-#ifdef HAS_SCHEMA_2x3
-extern void init_IteratorImplementation_Ifc2x3(IteratorFactoryImplementation*);
-#endif
-
-#ifdef HAS_SCHEMA_4
-extern void init_IteratorImplementation_Ifc4(IteratorFactoryImplementation*);
-#endif
-
-#ifdef HAS_SCHEMA_4x1
-extern void init_IteratorImplementation_Ifc4x1(IteratorFactoryImplementation*);
-#endif
-
-#ifdef HAS_SCHEMA_4x2
-extern void init_IteratorImplementation_Ifc4x2(IteratorFactoryImplementation*);
-#endif
-
-#ifdef HAS_SCHEMA_4x3_rc1
-extern void init_IteratorImplementation_Ifc4x3_rc1(IteratorFactoryImplementation*);
-#endif
-
-#ifdef HAS_SCHEMA_4x3_rc2
-extern void init_IteratorImplementation_Ifc4x3_rc2(IteratorFactoryImplementation*);
-#endif
+BOOST_PP_SEQ_FOR_EACH(EXTERNAL_DEFS, , SCHEMA_SEQ)
 
 IteratorFactoryImplementation::IteratorFactoryImplementation() {
-#ifdef HAS_SCHEMA_2x3
-	init_IteratorImplementation_Ifc2x3(this);
-#endif
-#ifdef HAS_SCHEMA_4
-	init_IteratorImplementation_Ifc4(this);
-#endif
-#ifdef HAS_SCHEMA_4x1
-	init_IteratorImplementation_Ifc4x1(this);
-#endif
-#ifdef HAS_SCHEMA_4x2
-	init_IteratorImplementation_Ifc4x2(this);
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-	init_IteratorImplementation_Ifc4x3_rc1(this);
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-	init_IteratorImplementation_Ifc4x3_rc2(this);
-#endif
+	BOOST_PP_SEQ_FOR_EACH(CALL_DEFS, , SCHEMA_SEQ)
 }
 
 void IteratorFactoryImplementation::bind(const std::string& schema_name, iterator_fn fn) {
diff --git a/src/ifcgeom_schema_agnostic/Kernel.cpp b/src/ifcgeom_schema_agnostic/Kernel.cpp
index 385979c555..fdea7a5d75 100644
--- a/src/ifcgeom_schema_agnostic/Kernel.cpp
+++ b/src/ifcgeom_schema_agnostic/Kernel.cpp
@@ -5,6 +5,9 @@
 #include <TopTools_IndexedMapOfShape.hxx>
 #include <TopTools_IndexedDataMapOfShapeListOfShape.hxx>
 
+#include <boost/preprocessor/stringize.hpp>
+#include <boost/preprocessor/seq/for_each.hpp>
+
 IfcGeom::Kernel::Kernel(IfcParse::IfcFile* file) {
 	if (file != 0) {
 		if (file->schema() == 0) {
@@ -48,44 +51,22 @@ IfcGeom::impl::KernelFactoryImplementation& IfcGeom::impl::kernel_implementation
 	return impl;
 }
 
-#ifdef HAS_SCHEMA_2x3
-extern void init_KernelImplementation_Ifc2x3(IfcGeom::impl::KernelFactoryImplementation*);
-#endif	
-#ifdef HAS_SCHEMA_4
-extern void init_KernelImplementation_Ifc4(IfcGeom::impl::KernelFactoryImplementation*);
-#endif	
-#ifdef HAS_SCHEMA_4x1
-extern void init_KernelImplementation_Ifc4x1(IfcGeom::impl::KernelFactoryImplementation*);
-#endif	
-#ifdef HAS_SCHEMA_4x2
-extern void init_KernelImplementation_Ifc4x2(IfcGeom::impl::KernelFactoryImplementation*);
-#endif	
-#ifdef HAS_SCHEMA_4x3_rc1
-extern void init_KernelImplementation_Ifc4x3_rc1(IfcGeom::impl::KernelFactoryImplementation*);
-#endif	
-#ifdef HAS_SCHEMA_4x3_rc2
-extern void init_KernelImplementation_Ifc4x3_rc2(IfcGeom::impl::KernelFactoryImplementation*);
-#endif
+// Declares the schema-based external kernel initialization routines:
+// - extern void init_KernelImplementation_Ifc2x3(IfcGeom::impl::KernelFactoryImplementation*);
+// - ...
+#define EXTERNAL_DEFS(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(extern void init_KernelImplementation_, elem), (IfcGeom::impl::KernelFactoryImplementation*);)
+
+// Declares the schema-based external iterator initialization routines:
+// - init_IteratorImplementation_Ifc2x3(this);
+// - ...
+#define CALL_DEFS(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(init_KernelImplementation_, elem), (this);)
+
+BOOST_PP_SEQ_FOR_EACH(EXTERNAL_DEFS, , SCHEMA_SEQ)
 
 IfcGeom::impl::KernelFactoryImplementation::KernelFactoryImplementation() {
-#ifdef HAS_SCHEMA_2x3
-	init_KernelImplementation_Ifc2x3(this);
-#endif	
-#ifdef HAS_SCHEMA_4
-	init_KernelImplementation_Ifc4(this);
-#endif	
-#ifdef HAS_SCHEMA_4x1
-	init_KernelImplementation_Ifc4x1(this);
-#endif	
-#ifdef HAS_SCHEMA_4x2
-	init_KernelImplementation_Ifc4x2(this);
-#endif	
-#ifdef HAS_SCHEMA_4x3_rc1
-	init_KernelImplementation_Ifc4x3_rc1(this);
-#endif	
-#ifdef HAS_SCHEMA_4x3_rc2
-	init_KernelImplementation_Ifc4x3_rc2(this);
-#endif
+	BOOST_PP_SEQ_FOR_EACH(CALL_DEFS, , SCHEMA_SEQ)
 }
 
 void IfcGeom::impl::KernelFactoryImplementation::bind(const std::string& schema_name, IfcGeom::impl::kernel_fn fn) {
@@ -155,6 +136,20 @@ IfcSchema::IfcObjectDefinition* get_decomposing_entity_impl(IfcSchema::IfcProduc
 	return parent;                                                                                               \
 }
 
+#define GET_RELATINGOBJECT_IFC4_VARIANT(IfcSchema)                                    \
+                                                                                      \
+IfcUtil::IfcBaseEntity* get_RelatingObject(IfcSchema::IfcRelDecomposes* decompose) {  \
+    IfcSchema::IfcRelAggregates* aggr = decompose->as<IfcSchema::IfcRelAggregates>(); \
+    if (aggr != nullptr) {                                                            \
+        return aggr->RelatingObject();                                                \
+    }                                                                                 \
+    IfcSchema::IfcRelNests* nest = decompose->as<IfcSchema::IfcRelNests>();           \
+    if (nest != nullptr) {                                                            \
+        return nest->RelatingObject();                                                \
+    }                                                                                 \
+    return nullptr;                                                                   \
+}
+
 namespace {
 
 #ifdef HAS_SCHEMA_2x3
@@ -165,113 +160,59 @@ namespace {
 #endif
 
 #ifdef HAS_SCHEMA_4
-	IfcUtil::IfcBaseEntity* get_RelatingObject(Ifc4::IfcRelDecomposes* decompose) {
-		Ifc4::IfcRelAggregates* aggr = decompose->as<Ifc4::IfcRelAggregates>();
-		if (aggr != nullptr) {
-			return aggr->RelatingObject();
-		}
-		Ifc4::IfcRelNests* nest = decompose->as<Ifc4::IfcRelNests>();
-		if (nest != nullptr) {
-			return nest->RelatingObject();
-		}
-		return nullptr;
-	}
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4);
 	CREATE_GET_DECOMPOSING_ENTITY(Ifc4);
 #endif
 
 #ifdef HAS_SCHEMA_4x1
-    IfcUtil::IfcBaseEntity* get_RelatingObject(Ifc4x1::IfcRelDecomposes* decompose) {
-		Ifc4x1::IfcRelAggregates* aggr = decompose->as<Ifc4x1::IfcRelAggregates>();
-		if (aggr != nullptr) {
-			return aggr->RelatingObject();
-		}
-		Ifc4x1::IfcRelNests* nest = decompose->as<Ifc4x1::IfcRelNests>();
-		if (nest != nullptr) {
-			return nest->RelatingObject();
-		}
-		return nullptr;
-	}
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4x1);
 	CREATE_GET_DECOMPOSING_ENTITY(Ifc4x1);
 #endif
 
 #ifdef HAS_SCHEMA_4x2
-    IfcUtil::IfcBaseEntity* get_RelatingObject(Ifc4x2::IfcRelDecomposes* decompose) {
-		Ifc4x2::IfcRelAggregates* aggr = decompose->as<Ifc4x2::IfcRelAggregates>();
-		if (aggr != nullptr) {
-			return aggr->RelatingObject();
-		}
-		Ifc4x2::IfcRelNests* nest = decompose->as<Ifc4x2::IfcRelNests>();
-		if (nest != nullptr) {
-			return nest->RelatingObject();
-		}
-		return nullptr;
-	}
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4x2);
 	CREATE_GET_DECOMPOSING_ENTITY(Ifc4x2);
 #endif
 
 #ifdef HAS_SCHEMA_4x3_rc1
-    IfcUtil::IfcBaseEntity* get_RelatingObject(Ifc4x3_rc1::IfcRelDecomposes* decompose) {
-		Ifc4x3_rc1::IfcRelAggregates* aggr = decompose->as<Ifc4x3_rc1::IfcRelAggregates>();
-		if (aggr != nullptr) {
-			return aggr->RelatingObject();
-		}
-		Ifc4x3_rc1::IfcRelNests* nest = decompose->as<Ifc4x3_rc1::IfcRelNests>();
-		if (nest != nullptr) {
-			return nest->RelatingObject();
-		}
-		return nullptr;
-	}
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4x3_rc1);
 	CREATE_GET_DECOMPOSING_ENTITY(Ifc4x3_rc1);
 #endif
 
 #ifdef HAS_SCHEMA_4x3_rc2
-	IfcUtil::IfcBaseEntity* get_RelatingObject(Ifc4x3_rc2::IfcRelDecomposes* decompose) {
-		Ifc4x3_rc2::IfcRelAggregates* aggr = decompose->as<Ifc4x3_rc2::IfcRelAggregates>();
-		if (aggr != nullptr) {
-			return aggr->RelatingObject();
-		}
-		Ifc4x3_rc2::IfcRelNests* nest = decompose->as<Ifc4x3_rc2::IfcRelNests>();
-		if (nest != nullptr) {
-			return nest->RelatingObject();
-		}
-		return nullptr;
-	}
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4x3_rc2);
 	CREATE_GET_DECOMPOSING_ENTITY(Ifc4x3_rc2);
 #endif
 	
+#ifdef HAS_SCHEMA_4x3_rc3
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4x3_rc3);
+	CREATE_GET_DECOMPOSING_ENTITY(Ifc4x3_rc3);
+#endif
+
+#ifdef HAS_SCHEMA_4x3_rc4
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4x3_rc4);
+	CREATE_GET_DECOMPOSING_ENTITY(Ifc4x3_rc4);
+#endif
+
+#ifdef HAS_SCHEMA_4x3
+	GET_RELATINGOBJECT_IFC4_VARIANT(Ifc4x3);
+	CREATE_GET_DECOMPOSING_ENTITY(Ifc4x3);
+#endif
 }
 
+// Declares the schema-based IfcProduct check:
+// - if (inst->as<Ifc2x3::IfcProduct>()) { ... }
+// - ...
+#define IFCPROCUCT_CHECK(r, data, elem) \
+	if (inst->as<BOOST_PP_CAT(Ifc, elem)::IfcProduct>()) { return get_decomposing_entity_impl(inst->as<BOOST_PP_CAT(Ifc, elem)::IfcProduct>(), include_openings); }
+
+#define GET_LAYERS(r, data, elem) \
+	if (inst->as<BOOST_PP_CAT(Ifc, elem)::IfcProduct>()) { return get_layers_impl<BOOST_PP_CAT(Ifc, elem)>(inst->as<BOOST_PP_CAT(Ifc, elem)::IfcProduct>()); }
+
+
 IfcUtil::IfcBaseEntity* IfcGeom::Kernel::get_decomposing_entity(IfcUtil::IfcBaseEntity* inst, bool include_openings) {
-#ifdef HAS_SCHEMA_2x3
-	if (inst->as<Ifc2x3::IfcProduct>()) {
-		return get_decomposing_entity_impl(inst->as<Ifc2x3::IfcProduct>(), include_openings);
-	}
-#endif
-#ifdef HAS_SCHEMA_4
-	if (inst->as<Ifc4::IfcProduct>()) {
-		return get_decomposing_entity_impl(inst->as<Ifc4::IfcProduct>(), include_openings);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x1
-	if (inst->as<Ifc4x1::IfcProduct>()) {
-		return get_decomposing_entity_impl(inst->as<Ifc4x1::IfcProduct>(), include_openings);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x2
-	if (inst->as<Ifc4x2::IfcProduct>()) {
-		return get_decomposing_entity_impl(inst->as<Ifc4x2::IfcProduct>(), include_openings);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-	if (inst->as<Ifc4x3_rc1::IfcProduct>()) {
-		return get_decomposing_entity_impl(inst->as<Ifc4x3_rc1::IfcProduct>(), include_openings);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-	if (inst->as<Ifc4x3_rc2::IfcProduct>()) {
-		return get_decomposing_entity_impl(inst->as<Ifc4x3_rc2::IfcProduct>(), include_openings);
-	}
-#endif
+	BOOST_PP_SEQ_FOR_EACH(IFCPROCUCT_CHECK, , SCHEMA_SEQ)
+
 	if (inst->declaration().name() == "IfcProject") {
 		return nullptr;
 	}
@@ -298,36 +239,7 @@ namespace {
 }
 
 std::map<std::string, IfcUtil::IfcBaseEntity*> IfcGeom::Kernel::get_layers(IfcUtil::IfcBaseEntity* inst) {
-#ifdef HAS_SCHEMA_2x3
-	if (inst->as<Ifc2x3::IfcProduct>()) {
-		return get_layers_impl<Ifc2x3>(inst->as<Ifc2x3::IfcProduct>());
-	}
-#endif
-#ifdef HAS_SCHEMA_4
-	if (inst->as<Ifc4::IfcProduct>()) {
-		return get_layers_impl<Ifc4>(inst->as<Ifc4::IfcProduct>());
-	}
-#endif
-#ifdef HAS_SCHEMA_4x1
-	if (inst->as<Ifc4x1::IfcProduct>()) {
-		return get_layers_impl<Ifc4x1>(inst->as<Ifc4x1::IfcProduct>());
-	}
-#endif
-#ifdef HAS_SCHEMA_4x2
-	if (inst->as<Ifc4x2::IfcProduct>()) {
-		return get_layers_impl<Ifc4x2>(inst->as<Ifc4x2::IfcProduct>());
-	}
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-	if (inst->as<Ifc4x3_rc1::IfcProduct>()) {
-		return get_layers_impl<Ifc4x3_rc1>(inst->as<Ifc4x3_rc1::IfcProduct>());
-	}
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-	if (inst->as<Ifc4x3_rc2::IfcProduct>()) {
-		return get_layers_impl<Ifc4x3_rc2>(inst->as<Ifc4x3_rc2::IfcProduct>());
-	}
-#endif
+	BOOST_PP_SEQ_FOR_EACH(GET_LAYERS, , SCHEMA_SEQ)
 
 	throw IfcParse::IfcException("Unexpected entity " + inst->declaration().name());
 }
diff --git a/src/ifcgeom_schema_agnostic/Kernel.h b/src/ifcgeom_schema_agnostic/Kernel.h
index 4d961cded0..930255c768 100644
--- a/src/ifcgeom_schema_agnostic/Kernel.h
+++ b/src/ifcgeom_schema_agnostic/Kernel.h
@@ -29,6 +29,9 @@
 #ifdef HAS_SCHEMA_4x3_rc4
 #include "../ifcparse/Ifc4x3_rc4.h"
 #endif
+#ifdef HAS_SCHEMA_4x3
+#include "../ifcparse/Ifc4x3.h"
+#endif
 
 #include <boost/function.hpp>
 
diff --git a/src/ifcgeom_schema_agnostic/Serialization.cpp b/src/ifcgeom_schema_agnostic/Serialization.cpp
index 11efb997f1..522b3eace8 100644
--- a/src/ifcgeom_schema_agnostic/Serialization.cpp
+++ b/src/ifcgeom_schema_agnostic/Serialization.cpp
@@ -2,143 +2,53 @@
 
 #include <boost/algorithm/string/case_conv.hpp>
 
+#include <boost/preprocessor/stringize.hpp>
+#include <boost/preprocessor/seq/for_each.hpp>
+#include <boost/algorithm/string/case_conv.hpp>
+
+#define EXTERNAL_DEFS_1(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(IfcUtil::IfcBaseClass* tesselate_, elem), (const TopoDS_Shape& shape, double deflection);)
+
+#define EXTERNAL_DEFS_2(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(IfcUtil::IfcBaseClass* serialise_, elem), (const TopoDS_Shape& shape, bool advanced);)
+
+#define CONDITIONAL_CALL(r, data, elem) \
+	if (schema_name_lower == BOOST_PP_STRINGIZE(BOOST_PP_CAT(elem,))) { \
+		return BOOST_PP_CAT(METHOD_NAME, elem)(shape, arg_2); \
+	}
+
 namespace IfcGeom {
-#ifdef HAS_SCHEMA_2x3
-	extern IfcUtil::IfcBaseClass* tesselate_Ifc2x3(const TopoDS_Shape& shape, double deflection);
-	extern IfcUtil::IfcBaseClass* serialise_Ifc2x3(const TopoDS_Shape& shape, bool advanced);
-#endif
-
-#ifdef HAS_SCHEMA_4
-	extern IfcUtil::IfcBaseClass* tesselate_Ifc4(const TopoDS_Shape& shape, double deflection);
-	extern IfcUtil::IfcBaseClass* serialise_Ifc4(const TopoDS_Shape& shape, bool advanced);
-#endif
-
-#ifdef HAS_SCHEMA_4x1
-	extern IfcUtil::IfcBaseClass* tesselate_Ifc4x1(const TopoDS_Shape& shape, double deflection);
-	extern IfcUtil::IfcBaseClass* serialise_Ifc4x1(const TopoDS_Shape& shape, bool advanced);
-#endif
-
-#ifdef HAS_SCHEMA_4x2
-	extern IfcUtil::IfcBaseClass* tesselate_Ifc4x2(const TopoDS_Shape& shape, double deflection);
-	extern IfcUtil::IfcBaseClass* serialise_Ifc4x2(const TopoDS_Shape& shape, bool advanced);
-#endif
-
-#ifdef HAS_SCHEMA_4x3_rc1
-	extern IfcUtil::IfcBaseClass* tesselate_Ifc4x3_rc1(const TopoDS_Shape& shape, double deflection);
-	extern IfcUtil::IfcBaseClass* serialise_Ifc4x3_rc1(const TopoDS_Shape& shape, bool advanced);
-#endif
-
-#ifdef HAS_SCHEMA_4x3_rc2
-	extern IfcUtil::IfcBaseClass* tesselate_Ifc4x3_rc2(const TopoDS_Shape& shape, double deflection);
-	extern IfcUtil::IfcBaseClass* serialise_Ifc4x3_rc2(const TopoDS_Shape& shape, bool advanced);
-#endif
+	BOOST_PP_SEQ_FOR_EACH(EXTERNAL_DEFS_1, , SCHEMA_SEQ);
+	BOOST_PP_SEQ_FOR_EACH(EXTERNAL_DEFS_2, , SCHEMA_SEQ);
 }
 
-template <typename Fn, typename T>
-IfcUtil::IfcBaseClass* execute_based_on_schema(
-#ifdef HAS_SCHEMA_2x3
-	Fn fn_2x3,
-#endif
-#ifdef HAS_SCHEMA_4
-	Fn fn_4,
-#endif
-#ifdef HAS_SCHEMA_4x1
-	Fn fn_4x1,
-#endif
-#ifdef HAS_SCHEMA_4x2
-	Fn fn_4x2,
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-	Fn fn_4x3_rc1,
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-	Fn fn_4x3_rc2,
-#endif
-	const std::string& schema_name, const TopoDS_Shape& shape, T t)
-{
+#define METHOD_NAME tesselate_
+
+IfcUtil::IfcBaseClass* IfcGeom::tesselate(const std::string& schema_name, const TopoDS_Shape& shape, double arg_2) {
 	// @todo an ugly hack to guarantee schemas are initialised.
 	try {
 		IfcParse::schema_by_name("IFC2X3");
 	} catch (IfcParse::IfcException&) {}
 
-	const std::string schema_name_lower = boost::to_lower_copy(schema_name);
+	const std::string schema_name_lower = boost::to_lower_copy(schema_name.substr(3));
 
-#ifdef HAS_SCHEMA_2x3
-	if (schema_name_lower == "ifc2x3") {
-		return fn_2x3(shape, t);
-	}
-#endif
-#ifdef HAS_SCHEMA_4
-	if (schema_name_lower == "ifc4") {
-		return fn_4(shape, t);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x1
-	if (schema_name_lower == "ifc4x1") {
-		return fn_4x1(shape, t);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x2
-	if (schema_name_lower == "ifc4x2") {
-		return fn_4x2(shape, t);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-	if (schema_name_lower == "ifc4x3_rc1") {
-		return fn_4x3_rc1(shape, t);
-	}
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-	if (schema_name_lower == "ifc4x3_rc2") {
-		return fn_4x3_rc2(shape, t);
-	}
-#endif
+	BOOST_PP_SEQ_FOR_EACH(CONDITIONAL_CALL, , SCHEMA_SEQ);
 
 	throw IfcParse::IfcException("No geometry serialization available for " + schema_name);
 }
 
-IfcUtil::IfcBaseClass* IfcGeom::tesselate(const std::string& schema_name, const TopoDS_Shape& shape, double deflection) {
-	return execute_based_on_schema(
-#ifdef HAS_SCHEMA_2x3
-		IfcGeom::tesselate_Ifc2x3,
-#endif
-#ifdef HAS_SCHEMA_4
-		IfcGeom::tesselate_Ifc4,
-#endif
-#ifdef HAS_SCHEMA_4x1
-		IfcGeom::tesselate_Ifc4x1,
-#endif
-#ifdef HAS_SCHEMA_4x2
-		IfcGeom::tesselate_Ifc4x2,
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-		IfcGeom::tesselate_Ifc4x3_rc1,
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-		IfcGeom::tesselate_Ifc4x3_rc2,
-#endif
-		schema_name, shape, deflection);
-}
+#undef METHOD_NAME
+#define METHOD_NAME serialise_
 
-IfcUtil::IfcBaseClass* IfcGeom::serialise(const std::string& schema_name, const TopoDS_Shape& shape, bool advanced) {
-	return execute_based_on_schema(
-#ifdef HAS_SCHEMA_2x3
-		IfcGeom::serialise_Ifc2x3,
-#endif
-#ifdef HAS_SCHEMA_4
-		IfcGeom::serialise_Ifc4,
-#endif
-#ifdef HAS_SCHEMA_4x1
-		IfcGeom::serialise_Ifc4x1,
-#endif
-#ifdef HAS_SCHEMA_4x2
-		IfcGeom::serialise_Ifc4x2,
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-		IfcGeom::serialise_Ifc4x3_rc1,
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-		IfcGeom::serialise_Ifc4x3_rc2,
-#endif
-		schema_name, shape, advanced);
+IfcUtil::IfcBaseClass* IfcGeom::serialise(const std::string& schema_name, const TopoDS_Shape& shape, bool arg_2) {
+	// @todo an ugly hack to guarantee schemas are initialised.
+	try {
+		IfcParse::schema_by_name("IFC2X3");
+	} catch (IfcParse::IfcException&) {}
+
+	const std::string schema_name_lower = boost::to_lower_copy(schema_name.substr(3));
+
+	BOOST_PP_SEQ_FOR_EACH(CONDITIONAL_CALL, , SCHEMA_SEQ);
+
+	throw IfcParse::IfcException("No geometry serialization available for " + schema_name);
 }
\ No newline at end of file
diff --git a/src/ifcparse/IfcHierarchyHelper.cpp b/src/ifcparse/IfcHierarchyHelper.cpp
index d00a67590f..b0109ac7ce 100644
--- a/src/ifcparse/IfcHierarchyHelper.cpp
+++ b/src/ifcparse/IfcHierarchyHelper.cpp
@@ -560,6 +560,14 @@ Ifc4x3_rc4::IfcStyledItem* create_styled_item(Ifc4x3_rc4::IfcRepresentationItem*
 }
 #endif
 
+#ifdef HAS_SCHEMA_4x3
+Ifc4x3::IfcStyledItem* create_styled_item(Ifc4x3::IfcRepresentationItem* item, Ifc4x3::IfcPresentationStyle* style) {
+	boost::shared_ptr<aggregate_of<Ifc4x3::IfcPresentationStyle>> styles(new aggregate_of<Ifc4x3::IfcPresentationStyle>());
+	styles->push(style);
+	return new Ifc4x3::IfcStyledItem(item, styles, boost::none);
+}
+#endif
+
 template <typename Schema>
 void setSurfaceColour_2x3(IfcHierarchyHelper<Schema>& file, typename Schema::IfcRepresentation* rep, typename Schema::IfcPresentationStyleAssignment* style_assignment)
 {
@@ -800,7 +808,32 @@ void setSurfaceColour(IfcHierarchyHelper<Ifc4x3_rc4>& file, Ifc4x3_rc4::IfcRepre
 }
 #endif
 
+#ifdef HAS_SCHEMA_4x3
+Ifc4x3::IfcPresentationStyle* addStyleAssignment(IfcHierarchyHelper<Ifc4x3>& file, double r, double g, double b, double a)
+{
+	return addStyleAssignment_4x3(file, r, g, b, a);
+}
 
+Ifc4x3::IfcPresentationStyle* setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcProductRepresentation* shape, double r, double g, double b, double a)
+{
+	return setSurfaceColour_4x3(file, shape, r, g, b, a);
+}
+
+Ifc4x3::IfcPresentationStyle* setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcRepresentation* shape, double r, double g, double b, double a)
+{
+	return setSurfaceColour_4x3(file, shape, r, g, b, a);
+}
+
+void setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcProductRepresentation* shape, Ifc4x3::IfcPresentationStyle* style)
+{
+	setSurfaceColour_4x3(file, shape, style);
+}
+
+void setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcRepresentation* shape, Ifc4x3::IfcPresentationStyle* style)
+{
+	setSurfaceColour_4x3(file, shape, style);
+}
+#endif
 
 template <typename Schema>
 typename Schema::IfcProductDefinitionShape* IfcHierarchyHelper<Schema>::addMappedItem(
@@ -923,4 +956,7 @@ template IFC_PARSE_API class IfcHierarchyHelper<Ifc4x3_rc3>;
 #endif
 #ifdef HAS_SCHEMA_4x3_rc4
 template IFC_PARSE_API class IfcHierarchyHelper<Ifc4x3_rc4>;
+#endif
+#ifdef HAS_SCHEMA_4x3
+template IFC_PARSE_API class IfcHierarchyHelper<Ifc4x3>;
 #endif
\ No newline at end of file
diff --git a/src/ifcparse/IfcHierarchyHelper.h b/src/ifcparse/IfcHierarchyHelper.h
index 3c462ba92f..84e29d842a 100644
--- a/src/ifcparse/IfcHierarchyHelper.h
+++ b/src/ifcparse/IfcHierarchyHelper.h
@@ -56,6 +56,9 @@
 #ifdef HAS_SCHEMA_4x3_rc4
 #include "../ifcparse/Ifc4x3_rc4.h"
 #endif
+#ifdef HAS_SCHEMA_4x3
+#include "../ifcparse/Ifc4x3.h"
+#endif
 
 #include "../ifcparse/IfcFile.h"
 #include "../ifcparse/IfcWrite.h"
@@ -238,6 +241,28 @@ namespace {
    }
 #endif
 
+#ifdef HAS_SCHEMA_4x3
+   Ifc4x3::IfcObjectDefinition* get_parent_of_relation(Ifc4x3::IfcRelContainedInSpatialStructure* t) {
+	   return t->RelatingStructure();
+   }
+
+   aggregate_of_instance::ptr get_children_of_relation(Ifc4x3::IfcRelContainedInSpatialStructure* t) {
+	   return t->RelatedElements()->generalize();
+   }
+
+   aggregate_of_instance::ptr get_children_of_relation(Ifc4x3::IfcRelAggregates* t) {
+	   return t->RelatedObjects()->generalize();
+   }
+
+   void set_children_of_relation(Ifc4x3::IfcRelContainedInSpatialStructure* t, aggregate_of_instance::ptr& cs) {
+	   t->setRelatedElements(cs->as<Ifc4x3::IfcProduct>());
+   }
+
+   void set_children_of_relation(Ifc4x3::IfcRelAggregates* t, aggregate_of_instance::ptr& cs) {
+	   t->setRelatedObjects(cs->as<Ifc4x3::IfcObjectDefinition>());
+   }
+#endif
+
 	IfcUtil::IfcBaseClass* get_parent_of_relation(IfcUtil::IfcBaseClass* t) {
 		return *t->data().getArgument(
 			t->declaration().as_entity()->attribute_index("RelatingObject")
@@ -464,6 +489,14 @@ IFC_PARSE_API void setSurfaceColour(IfcHierarchyHelper<Ifc4x3_rc4>& file, Ifc4x3
 IFC_PARSE_API void setSurfaceColour(IfcHierarchyHelper<Ifc4x3_rc4>& file, Ifc4x3_rc4::IfcRepresentation* shape, Ifc4x3_rc4::IfcPresentationStyle* style);
 #endif
 
+#ifdef HAS_SCHEMA_4x3
+IFC_PARSE_API Ifc4x3::IfcPresentationStyle* addStyleAssignment(IfcHierarchyHelper<Ifc4x3>& file, double r, double g, double b, double a = 1.0);
+IFC_PARSE_API Ifc4x3::IfcPresentationStyle* setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcProductRepresentation* shape, double r, double g, double b, double a = 1.0);
+IFC_PARSE_API Ifc4x3::IfcPresentationStyle* setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcRepresentation* shape, double r, double g, double b, double a = 1.0);
+IFC_PARSE_API void setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcProductRepresentation* shape, Ifc4x3::IfcPresentationStyle* style);
+IFC_PARSE_API void setSurfaceColour(IfcHierarchyHelper<Ifc4x3>& file, Ifc4x3::IfcRepresentation* shape, Ifc4x3::IfcPresentationStyle* style);
+#endif
+
 /*
 template <>
 inline void IfcHierarchyHelper::addRelatedObject <typename Schema::IfcRelContainedInSpatialStructure> (typename Schema::IfcObjectDefinition* relating_structure, 
diff --git a/src/ifcparse/IfcSIPrefix.cpp b/src/ifcparse/IfcSIPrefix.cpp
index e851785ecb..4d53ec99ac 100644
--- a/src/ifcparse/IfcSIPrefix.cpp
+++ b/src/ifcparse/IfcSIPrefix.cpp
@@ -43,6 +43,9 @@
 #ifdef HAS_SCHEMA_4x3_rc4
 #include "../ifcparse/Ifc4x3_rc4.h"
 #endif
+#ifdef HAS_SCHEMA_4x3
+#include "../ifcparse/Ifc4x3.h"
+#endif
 
 double IfcParse::IfcSIPrefixToValue(const std::string& v) {
 	if      ( v == "EXA"   ) return 1.e18;
@@ -119,6 +122,9 @@ template double IFC_PARSE_API IfcParse::get_SI_equivalent<Ifc4x3_rc3>(Ifc4x3_rc3
 #ifdef HAS_SCHEMA_4x3_rc4
 template double IFC_PARSE_API IfcParse::get_SI_equivalent<Ifc4x3_rc4>(Ifc4x3_rc4::IfcNamedUnit* named_unit);
 #endif
+#ifdef HAS_SCHEMA_4x3
+template double IFC_PARSE_API IfcParse::get_SI_equivalent<Ifc4x3>(Ifc4x3_rc4::IfcNamedUnit* named_unit);
+#endif
 
 #else
 
@@ -146,5 +152,8 @@ template double IFC_PARSE_API IfcParse::get_SI_equivalent<Ifc4x3_rc3>(typename I
 #ifdef HAS_SCHEMA_4x3_rc4
 template double IFC_PARSE_API IfcParse::get_SI_equivalent<Ifc4x3_rc4>(typename Ifc4x3_rc4::IfcNamedUnit* named_unit);
 #endif
+#ifdef HAS_SCHEMA_4x3
+template double IFC_PARSE_API IfcParse::get_SI_equivalent<Ifc4x3>(typename Ifc4x3::IfcNamedUnit* named_unit);
+#endif
 
 #endif
diff --git a/src/ifcparse/IfcSchema.cpp b/src/ifcparse/IfcSchema.cpp
index 6c7bee5b0c..817c9082e7 100644
--- a/src/ifcparse/IfcSchema.cpp
+++ b/src/ifcparse/IfcSchema.cpp
@@ -116,6 +116,9 @@ void IfcParse::register_schema(schema_definition* s) {
 #ifdef HAS_SCHEMA_4x3_rc4
 #include "../ifcparse/Ifc4x3_rc4.h"
 #endif
+#ifdef HAS_SCHEMA_4x3
+#include "../ifcparse/Ifc4x3.h"
+#endif
 
 const IfcParse::schema_definition* IfcParse::schema_by_name(const std::string& name) {
 	// TODO: initialize automatically somehow
@@ -143,6 +146,9 @@ const IfcParse::schema_definition* IfcParse::schema_by_name(const std::string& n
 #ifdef HAS_SCHEMA_4x3_rc4
    Ifc4x3_rc4::get_schema();
 #endif
+#ifdef HAS_SCHEMA_4x3
+   Ifc4x3::get_schema();
+#endif
 
 	std::map<std::string, const IfcParse::schema_definition*>::const_iterator it = schemas.find(boost::to_upper_copy(name));
 	if (it == schemas.end()) {
@@ -191,6 +197,9 @@ void IfcParse::clear_schemas() {
 #ifdef HAS_SCHEMA_4x3_rc4
 	Ifc4x3_rc4::clear_schema();
 #endif
+#ifdef HAS_SCHEMA_4x3
+	Ifc4x3::clear_schema();
+#endif
 
 	// clear any remaining registered schemas
 	// we pop schemas until map is empty, because map iteration is invalidated after each erasure
diff --git a/src/ifcwrap/IfcGeomWrapper.i b/src/ifcwrap/IfcGeomWrapper.i
index 4f7f08ca9d..45b2bb761a 100644
--- a/src/ifcwrap/IfcGeomWrapper.i
+++ b/src/ifcwrap/IfcGeomWrapper.i
@@ -586,6 +586,21 @@ struct ShapeRTTI : public boost::static_visitor<PyObject*>
 			return helper_fn_create_shape<Ifc4x3_rc2>(settings, instance, representation);
 		}
 		#endif
+		#ifdef HAS_SCHEMA_4x3_rc3
+		if (schema_name == "IFC4X3_RC3") {
+			return helper_fn_create_shape<Ifc4x3_rc3>(settings, instance, representation);
+		}
+		#endif
+		#ifdef HAS_SCHEMA_4x3_rc4
+		if (schema_name == "IFC4X3_RC4") {
+			return helper_fn_create_shape<Ifc4x3_rc4>(settings, instance, representation);
+		}
+		#endif
+		#ifdef HAS_SCHEMA_4x3
+		if (schema_name == "IFC4X3") {
+			return helper_fn_create_shape<Ifc4x3>(settings, instance, representation);
+		}
+		#endif
 		
 		throw IfcParse::IfcException("No geometry support for " + schema_name);
 	}
diff --git a/src/ifcwrap/IfcPython.i b/src/ifcwrap/IfcPython.i
index dd1517c998..e795245049 100644
--- a/src/ifcwrap/IfcPython.i
+++ b/src/ifcwrap/IfcPython.i
@@ -109,6 +109,9 @@
 #endif
 #ifdef HAS_SCHEMA_4x3_rc4
 #include "../ifcparse/Ifc4x3_rc4.h"
+#endif
+#ifdef HAS_SCHEMA_4x3
+#include "../ifcparse/Ifc4x3.h"
 #endif
 
 	#include "../ifcparse/IfcBaseClass.h"
@@ -159,6 +162,15 @@
 #ifdef HAS_SCHEMA_4x3_rc2
 	#include "../ifcparse/Ifc4x3_rc2.h"
 #endif
+#ifdef HAS_SCHEMA_4x3_rc3
+	#include "../ifcparse/Ifc4x3_rc3.h"
+#endif
+#ifdef HAS_SCHEMA_4x3_rc4
+	#include "../ifcparse/Ifc4x3_rc4.h"
+#endif
+#ifdef HAS_SCHEMA_4x3
+	#include "../ifcparse/Ifc4x3.h"
+#endif
 
 	#include "../ifcparse/IfcBaseClass.h"
 	#include "../ifcparse/IfcFile.h"
diff --git a/src/serializers/XmlSerializer.cpp b/src/serializers/XmlSerializer.cpp
index dea89823f5..81386fb33e 100644
--- a/src/serializers/XmlSerializer.cpp
+++ b/src/serializers/XmlSerializer.cpp
@@ -1,43 +1,19 @@
 #include "XmlSerializer.h"
 
-#ifdef HAS_SCHEMA_2x3
-extern void init_XmlSerializerIfc2x3(XmlSerializerFactory::Factory*);
-#endif
-#ifdef HAS_SCHEMA_4
-extern void init_XmlSerializerIfc4(XmlSerializerFactory::Factory*);
-#endif
-#ifdef HAS_SCHEMA_4x1
-extern void init_XmlSerializerIfc4x1(XmlSerializerFactory::Factory*);
-#endif
-#ifdef HAS_SCHEMA_4x2
-extern void init_XmlSerializerIfc4x2(XmlSerializerFactory::Factory*);
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-extern void init_XmlSerializerIfc4x3_rc1(XmlSerializerFactory::Factory*);
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-extern void init_XmlSerializerIfc4x3_rc2(XmlSerializerFactory::Factory*);
-#endif
+#include <boost/preprocessor/stringize.hpp>
+#include <boost/preprocessor/seq/for_each.hpp>
+#include <boost/algorithm/string/case_conv.hpp>
+
+#define EXTERNAL_DEFS(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(extern void init_XmlSerializer, elem), (XmlSerializerFactory::Factory*);)
+
+#define CALL_DEFS(r, data, elem) \
+	BOOST_PP_CAT(BOOST_PP_CAT(init_XmlSerializer, elem), (this);)
+
+BOOST_PP_SEQ_FOR_EACH(EXTERNAL_DEFS, , SCHEMA_SEQ)
 
 XmlSerializerFactory::Factory::Factory() {
-#ifdef HAS_SCHEMA_2x3
-	init_XmlSerializerIfc2x3(this);
-#endif
-#ifdef HAS_SCHEMA_4
-	init_XmlSerializerIfc4(this);
-#endif
-#ifdef HAS_SCHEMA_4x1
-	init_XmlSerializerIfc4x1(this);
-#endif
-#ifdef HAS_SCHEMA_4x2
-	init_XmlSerializerIfc4x2(this);
-#endif
-#ifdef HAS_SCHEMA_4x3_rc1
-	init_XmlSerializerIfc4x3_rc1(this);
-#endif
-#ifdef HAS_SCHEMA_4x3_rc2
-	init_XmlSerializerIfc4x3_rc2(this);
-#endif
+	BOOST_PP_SEQ_FOR_EACH(CALL_DEFS, , SCHEMA_SEQ)
 }
 
 void XmlSerializerFactory::Factory::bind(const std::string& schema_name, fn f) {