diff --git a/src/ifcgeom/kernels/manifold/ManifoldConversionResult.cpp b/src/ifcgeom/kernels/manifold/ManifoldConversionResult.cpp
index 82931f87ad..ec53254bcd 100644
--- a/src/ifcgeom/kernels/manifold/ManifoldConversionResult.cpp
+++ b/src/ifcgeom/kernels/manifold/ManifoldConversionResult.cpp
@@ -180,6 +180,12 @@ namespace {
 	}
 }
 
+ifcopenshell::geometry::ManifoldShape::ManifoldShape(const manifold::Manifold& solid) {
+    auto copy = solid;
+    auto with_normals = copy.CalculateNormals(3);
+    parts_.push_back({with_normals.GetMeshGL64(), solid});
+}
+
 ifcopenshell::geometry::ManifoldShape::ManifoldShape(const ManifoldPart& part)
 	: parts_{ part } {}
 
@@ -221,6 +227,12 @@ void ifcopenshell::geometry::ManifoldShape::Triangulate(ifcopenshell::geometry::
 				mesh.vertProperties[i * mesh.numProp + 0],
 				mesh.vertProperties[i * mesh.numProp + 1],
 				mesh.vertProperties[i * mesh.numProp + 2]);
+            if (mesh.numProp == 6) {
+				t->addNormal(
+					mesh.vertProperties[i * mesh.numProp + 3],
+					mesh.vertProperties[i * mesh.numProp + 4],
+					mesh.vertProperties[i * mesh.numProp + 5]);
+            }
 		}
 		auto edges = count_edges(mesh);
 		for (size_t i = 0; i < mesh.NumTri(); ++i) {
@@ -499,7 +511,7 @@ ConversionResultShape* ifcopenshell::geometry::ManifoldShape::moved(ifcopenshell
 		if (part.solid && !solid) {
 			throw std::runtime_error("Failed to transform shape");
 		}
-		moved_parts.push_back({ std::move(mesh), std::move(solid) });
+		moved_parts.emplace_back(mesh, *solid);
 	}
 	return new ManifoldShape(std::move(moved_parts));
 }
diff --git a/src/ifcgeom/kernels/manifold/ManifoldConversionResult.h b/src/ifcgeom/kernels/manifold/ManifoldConversionResult.h
index 9250dbfd53..1feb466287 100644
--- a/src/ifcgeom/kernels/manifold/ManifoldConversionResult.h
+++ b/src/ifcgeom/kernels/manifold/ManifoldConversionResult.h
@@ -14,12 +14,24 @@ namespace geometry {
 struct IFC_GEOMLIBRARY_API ManifoldPart {
 	manifold::MeshGL64 mesh;
 	std::optional<manifold::Manifold> solid;
+
+	ManifoldPart(const manifold::Manifold& s) {
+        auto copy = s;
+        copy.CalculateNormals(3);
+        mesh = copy.GetMeshGL64();
+        solid = s;	
+	}
+
+	ManifoldPart(const manifold::MeshGL64& s) : mesh(s) {}
+
+	ManifoldPart(const manifold::MeshGL64& s, const manifold::Manifold& m) : mesh(s), solid(m) {}
 };
 
 class IFC_GEOMLIBRARY_API ManifoldShape : public IfcGeom::ConversionResultShape {
 public:
 	ManifoldShape() = default;
-	explicit ManifoldShape(const ManifoldPart& part);
+    explicit ManifoldShape(const manifold::Manifold& part);
+    explicit ManifoldShape(const ManifoldPart& part);
 	explicit ManifoldShape(ManifoldPart&& part);
 	explicit ManifoldShape(const std::vector<ManifoldPart>& parts);
 	explicit ManifoldShape(std::vector<ManifoldPart>&& parts);
diff --git a/src/ifcgeom/kernels/manifold/ManifoldKernel.cpp b/src/ifcgeom/kernels/manifold/ManifoldKernel.cpp
index bb9b34211c..109d54f02d 100644
--- a/src/ifcgeom/kernels/manifold/ManifoldKernel.cpp
+++ b/src/ifcgeom/kernels/manifold/ManifoldKernel.cpp
@@ -1066,9 +1066,9 @@ namespace {
 			return std::nullopt;
 		}
 		if (solid) {
-			return Part{ solid->GetMeshGL64(), solid };
+            return *solid;
 		}
-		return Part{ mesh, std::nullopt };
+		return mesh;
 	}
 
 	std::optional<Part> part_from_shell(const taxonomy::shell::ptr& shell, double precision, double dilation, manifold::Manifold::Error* status_ptr = nullptr) {
@@ -1544,7 +1544,7 @@ bool ManifoldKernel::convert_impl(const taxonomy::solid::ptr solid, IfcGeom::Con
 	results.emplace_back(IfcGeom::ConversionResult(
 		solid->instance.id(),
 		solid->matrix,
-		new ifcopenshell::geometry::ManifoldShape(Part{ result.GetMeshGL64(), result }),
+		new ifcopenshell::geometry::ManifoldShape(result),
 		solid->surface_style));
 	return true;
 }
@@ -1622,7 +1622,7 @@ bool ManifoldKernel::convert_impl(const taxonomy::boolean_result::ptr br, IfcGeo
 	results.emplace_back(IfcGeom::ConversionResult(
 		br->instance.id(),
 		br->matrix,
-		new ifcopenshell::geometry::ManifoldShape(Part{ result->GetMeshGL64(), *result }),
+		new ifcopenshell::geometry::ManifoldShape(*result),
 		br->surface_style ? br->surface_style : style));
 	return true;
 }
@@ -1671,7 +1671,7 @@ bool ManifoldKernel::convert_openings(const express::Base&, const std::vector<st
 		auto result = *operand - opening_union;
 		cut_shapes.emplace_back(IfcGeom::ConversionResult(
 			entity_shape.ItemId(),
-			new ifcopenshell::geometry::ManifoldShape(Part{ result.GetMeshGL64(), result }),
+			new ifcopenshell::geometry::ManifoldShape(result),
 			entity_shape.StylePtr()));
 	}
 	return !cut_shapes.empty();