diff --git a/src/examples/IfcParseExamples.cpp b/src/examples/IfcParseExamples.cpp
index 2bdb84957f..3e729553a7 100644
--- a/src/examples/IfcParseExamples.cpp
+++ b/src/examples/IfcParseExamples.cpp
@@ -29,10 +29,11 @@ int main(int argc, char** argv) {
 	}
 
 	// Redirect the output (both progress and log) to stdout
-	Ifc::SetOutput(&std::cout,&std::cout);
+	Logger::SetOutput(&std::cout,&std::cout);
 
 	// Parse the IFC file provided in argv[1]
-	if ( ! Ifc::Init(argv[1]) ) {
+	IfcParse::IfcFile file;
+	if ( ! file.Init(argv[1]) ) {
 		std::cout << "Unable to parse .ifc file" << std::endl;
 		return 1;
 	}
@@ -53,12 +54,7 @@ int main(int argc, char** argv) {
 	// we need to cast them to IfcWindows. Since these properties 
 	// are optional we need to make sure the properties are 
 	// defined for the window in question before accessing them.
-	//
-	// Since we are accessing properties that represent a length
-	// measure we can multiply the value by Ifc::LengthUnit, which
-	// contains the ratio of the unit defined in the IfcUnitAssignment
-	// to the standard SI Unit, the meter.
-	IfcBuildingElement::list elements = Ifc::EntitiesByType<IfcBuildingElement>();
+	IfcBuildingElement::list elements = file.EntitiesByType<IfcBuildingElement>();
 
 	std::cout << "Found " << elements->Size() << " elements in " << argv[1] << ":" << std::endl;
 	
@@ -71,8 +67,8 @@ int main(int argc, char** argv) {
 			const IfcWindow::ptr window = reinterpret_pointer_cast<IfcBuildingElement,IfcWindow>(element);
 			
 			if ( window->hasOverallWidth() && window->hasOverallHeight() ) {
-				const float area = window->OverallWidth()*window->OverallHeight() * (Ifc::LengthUnit*Ifc::LengthUnit);
-				std::cout << "This window has an area of " << area << "m2" << std::endl;
+				const double area = window->OverallWidth()*window->OverallHeight();
+				std::cout << "The area of this window is " << area << std::endl;
 			}
 		}
 
diff --git a/src/ifcgeom/IfcGeom.h b/src/ifcgeom/IfcGeom.h
index 9c6b55a917..c750cdd0f2 100644
--- a/src/ifcgeom/IfcGeom.h
+++ b/src/ifcgeom/IfcGeom.h
@@ -47,16 +47,32 @@ namespace IfcGeom {
 	// Tolerances and settings for various geometrical operations:
 	enum GeomValue {
 		// Specifies the deflection of the mesher
+		// Default: 0.001m / 1mm
 		GV_DEFLECTION_TOLERANCE, 
 		// Specifies the tolerance of the wire builder, most notably for trimmed curves
+		// Defailt: 0.0001m / 0.1mm
 		GV_WIRE_CREATION_TOLERANCE,
 		// Specifies the minimal area of a face to be included in an IfcConnectedFaceset
+		// Default: 0.000001m 0.01cm2
 		GV_MINIMAL_FACE_AREA,
 		// Specifies the treshold distance under which cartesian points are deemed equal
+		// Default: 0.00001m / 0.01mm
 		GV_POINT_EQUALITY_TOLERANCE,
 		// Specifies maximum number of faces for a shell to be sewed. Sewing shells
 		// that consist of many faces is really detrimental for the performance.
-		GV_MAX_FACES_TO_SEW
+		// Default: 1000
+		GV_MAX_FACES_TO_SEW,
+		// By default singular faces have no explicitly defined orientation, to
+		// force faces to be defined CounterClockWise, set this value greater than zero.
+		GV_FORCE_CCW_FACE_ORIENTATION,
+		// The length unit used the creation of TopoDS_Shapes, primarily affects the
+		// interpretation of IfcCartesianPoints and IfcVector magnitudes
+		// DefaultL 1.0
+		GV_LENGTH_UNIT,
+		// The plane angle unit used for the creation of TopoDS_Shapes, primarily affects
+		// the interpretation of IfcParamaterValues of IfcTrimmedCurves
+		// Default: -1.0 (= not set, fist try degrees, then radians)
+		GV_PLANEANGLE_UNIT,
 	};
 
 	bool convert_wire_to_face(const TopoDS_Wire& wire, TopoDS_Face& face);
@@ -80,7 +96,7 @@ namespace IfcGeom {
 	double face_area(const TopoDS_Face& f);
 	void SetValue(GeomValue var, double value);
 	double GetValue(GeomValue var);
-
+	
 	namespace Cache {
 		void Purge();
 		void PurgeShapeCache();
diff --git a/src/ifcgeom/IfcGeomCurves.cpp b/src/ifcgeom/IfcGeomCurves.cpp
index 443b734b49..37b2297b63 100644
--- a/src/ifcgeom/IfcGeomCurves.cpp
+++ b/src/ifcgeom/IfcGeomCurves.cpp
@@ -78,7 +78,7 @@
 #include "../ifcgeom/IfcGeom.h"
 
 bool IfcGeom::convert(const Ifc2x3::IfcCircle::ptr l, Handle(Geom_Curve)& curve) {
-	const double r = l->Radius() * Ifc::LengthUnit;
+	const double r = l->Radius() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	if ( r <= 0.0f ) { return false; }
 	gp_Trsf trsf;
 	Ifc2x3::IfcAxis2Placement placement = l->Position();
@@ -94,8 +94,8 @@ bool IfcGeom::convert(const Ifc2x3::IfcCircle::ptr l, Handle(Geom_Curve)& curve)
 	return true;
 }
 bool IfcGeom::convert(const Ifc2x3::IfcEllipse::ptr l, Handle(Geom_Curve)& curve) {
-	double x = l->SemiAxis1() * Ifc::LengthUnit;
-	double y = l->SemiAxis2() * Ifc::LengthUnit;
+	double x = l->SemiAxis1() * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	double y = l->SemiAxis2() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	if ( x == 0.0f || y == 0.0f || y > x ) { return false; }
 	gp_Trsf trsf;
 	Ifc2x3::IfcAxis2Placement placement = l->Position();
diff --git a/src/ifcgeom/IfcGeomFaces.cpp b/src/ifcgeom/IfcGeomFaces.cpp
index 1b7ac98cb6..7a206d7f96 100644
--- a/src/ifcgeom/IfcGeomFaces.cpp
+++ b/src/ifcgeom/IfcGeomFaces.cpp
@@ -74,6 +74,7 @@
 #include <ShapeFix_Solid.hxx>
 
 #include <TopLoc_Location.hxx>
+#include <BRepGProp_Face.hxx>
 
 #include "../ifcgeom/IfcGeom.h"
 
@@ -81,15 +82,15 @@ bool IfcGeom::convert(const Ifc2x3::IfcFace::ptr l, TopoDS_Face& face) {
 	Ifc2x3::IfcFaceBound::list bounds = l->Bounds();
 	Ifc2x3::IfcFaceBound::it it = bounds->begin();
 	Ifc2x3::IfcLoop::ptr loop = (*it)->Bound();
-	TopoDS_Wire wire;
-	if ( ! IfcGeom::convert_wire(loop,wire) ) return false;
-	BRepBuilderAPI_MakeFace mf (wire);
+	TopoDS_Wire outer_wire;
+	if ( ! IfcGeom::convert_wire(loop,outer_wire) ) return false;
+	BRepBuilderAPI_MakeFace mf (outer_wire);
 	BRepBuilderAPI_FaceError er = mf.Error();
 	if ( er == BRepBuilderAPI_NotPlanar ) {
 		ShapeFix_ShapeTolerance FTol;
-		FTol.SetTolerance(wire, 0.01, TopAbs_WIRE);
+		FTol.SetTolerance(outer_wire, 0.01, TopAbs_WIRE);
 		mf.~BRepBuilderAPI_MakeFace();
-		new (&mf) BRepBuilderAPI_MakeFace(wire);
+		new (&mf) BRepBuilderAPI_MakeFace(outer_wire);
 		er = mf.Error();
 	}
 	if ( er != BRepBuilderAPI_FaceDone ) return false;
@@ -116,6 +117,65 @@ bool IfcGeom::convert(const Ifc2x3::IfcFace::ptr l, TopoDS_Face& face) {
 			return false;
 		}
 	}
+
+	if ( IfcGeom::GetValue(GV_FORCE_CCW_FACE_ORIENTATION)>0 ) { 
+	// Check the orientation of the face by comparing the 
+	// normal of the topological surface to the Newell's Method's
+	// normal. Newell's Method is used for the normal calculation
+	// as a simple edge cross product can give opposite results
+	// for a concave face boundary.
+	// Reference: Graphics Gems III p. 231
+	BRepGProp_Face prop(face);
+	gp_Vec normal_direction;
+	gp_Pnt center;
+	double u1,u2,v1,v2;
+	prop.Bounds(u1,u2,v1,v2);
+	prop.Normal((u1+u2)/2.0,(v1+v2)/2.0,center,normal_direction);						
+	gp_Dir face_normal1 = gp_Dir(normal_direction.XYZ());
+
+	double x = 0, y = 0, z = 0;
+	gp_Pnt current, previous, first;
+	int n = 0;
+	// Iterate over the vertices of the outer wire (discarding
+	// any potential holes)
+	for ( TopExp_Explorer exp(outer_wire,TopAbs_VERTEX);; exp.Next()) {
+		unsigned has_more = exp.More();
+		if ( has_more ) {
+			const TopoDS_Vertex& v = TopoDS::Vertex(exp.Current());
+			current = BRep_Tool::Pnt(v);
+		} else {
+			current = first;			
+		}
+		if ( n ) {
+			const double& xn  = previous.X();
+			const double& yn  = previous.Y();
+			const double& zn  = previous.Z();
+			const double& xn1 =  current.X();
+			const double& yn1 =  current.Y();
+			const double& zn1 =  current.Z();
+			x += (yn-yn1)*(zn+zn1);
+			y += (xn+xn1)*(zn-zn1);
+			z += (xn-xn1)*(yn+yn1);
+		} else {
+			first = current;
+		}
+		if ( !has_more ) {
+			break;
+		} 
+		previous = current;
+		++n;
+	}
+
+	// If Newell's normal does not point in the same direction
+	// as the topological face normal the face orientation is
+	// reversed
+	gp_Vec face_normal2(x,y,z);
+	if ( face_normal1.Dot(face_normal2) < 0 ) {
+		TopAbs_Orientation o = face.Orientation();
+		face.Orientation(o == TopAbs_FORWARD ? TopAbs_REVERSED : TopAbs_FORWARD);
+	}
+	}
+	
 	// It might be a good idea to globally discard faces
 	// smaller than a certain treshold value. But for now
 	// only when processing IfcConnectedFacesets the small
@@ -145,11 +205,11 @@ bool IfcGeom::convert(const Ifc2x3::IfcArbitraryProfileDefWithVoids::ptr l, Topo
 	return true;
 }
 bool IfcGeom::convert(const Ifc2x3::IfcRectangleProfileDef::ptr l, TopoDS_Face& face) {
-	const double x = l->XDim() / 2.0f * Ifc::LengthUnit;
-	const double y = l->YDim() / 2.0f  * Ifc::LengthUnit;
+	const double x = l->XDim() / 2.0f * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double y = l->YDim() / 2.0f  * IfcGeom::GetValue(GV_LENGTH_UNIT);
 
 	if ( x == 0.0f || y == 0.0f ) {
-		Ifc::LogMessage("Notice","Skipping zero sized profile:",l->entity);
+		Logger::Message(Logger::LOG_NOTICE,"Skipping zero sized profile:",l->entity);
 		return false;
 	}
 
@@ -159,18 +219,18 @@ bool IfcGeom::convert(const Ifc2x3::IfcRectangleProfileDef::ptr l, TopoDS_Face&
 	return IfcGeom::profile_helper(4,coords,0,0,0,trsf2d,face);
 }
 bool IfcGeom::convert(const Ifc2x3::IfcIShapeProfileDef::ptr l, TopoDS_Face& face) {
-	const double x = l->OverallWidth() / 2.0f * Ifc::LengthUnit;
-	const double y = l->OverallDepth() / 2.0f * Ifc::LengthUnit;
-	const double d1 = l->WebThickness() / 2.0f  * Ifc::LengthUnit;
-	const double d2 = l->FlangeThickness() * Ifc::LengthUnit;
+	const double x = l->OverallWidth() / 2.0f * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double y = l->OverallDepth() / 2.0f * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double d1 = l->WebThickness() / 2.0f  * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double d2 = l->FlangeThickness() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	bool doFillet = l->hasFilletRadius();
 	double f;
 	if ( doFillet ) {
-		f = l->FilletRadius() * Ifc::LengthUnit;
+		f = l->FilletRadius() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	}
 
 	if ( x == 0.0f || y == 0.0f || d1 == 0.0f || d2 == 0.0f ) {
-		Ifc::LogMessage("Notice","Skipping zero sized profile:",l->entity);
+		Logger::Message(Logger::LOG_NOTICE,"Skipping zero sized profile:",l->entity);
 		return false;
 	}
 
@@ -183,19 +243,19 @@ bool IfcGeom::convert(const Ifc2x3::IfcIShapeProfileDef::ptr l, TopoDS_Face& fac
 	return IfcGeom::profile_helper(12,coords,doFillet ? 4 : 0,fillets,radii,trsf2d,face);
 }
 bool IfcGeom::convert(const Ifc2x3::IfcCShapeProfileDef::ptr l, TopoDS_Face& face) {
-	const double x = l->Depth() / 2.0f * Ifc::LengthUnit;
-	const double y = l->Width() / 2.0f * Ifc::LengthUnit;
-	const double d1 = l->WallThickness() * Ifc::LengthUnit;
-	const double d2 = l->Girth() * Ifc::LengthUnit;
+	const double x = l->Depth() / 2.0f * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double y = l->Width() / 2.0f * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double d1 = l->WallThickness() * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double d2 = l->Girth() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	bool doFillet = l->hasInternalFilletRadius();
 	double f1,f2;
 	if ( doFillet ) {
-		f1 = l->InternalFilletRadius() * Ifc::LengthUnit;
+		f1 = l->InternalFilletRadius() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 		f2 = f1 + d1;
 	}
 
 	if ( x == 0.0f || y == 0.0f || d1 == 0.0f || d2 == 0.0f ) {
-		Ifc::LogMessage("Notice","Skipping zero sized profile:",l->entity);
+		Logger::Message(Logger::LOG_NOTICE,"Skipping zero sized profile:",l->entity);
 		return false;
 	}
 
@@ -208,21 +268,21 @@ bool IfcGeom::convert(const Ifc2x3::IfcCShapeProfileDef::ptr l, TopoDS_Face& fac
 	return IfcGeom::profile_helper(12,coords,doFillet ? 8 : 0,fillets,radii,trsf2d,face);
 }
 bool IfcGeom::convert(const Ifc2x3::IfcLShapeProfileDef::ptr l, TopoDS_Face& face) {
-	const double y = l->Depth() / 2.0f * Ifc::LengthUnit;
-	const double x = l->Width() / 2.0f * Ifc::LengthUnit;
-	const double d = l->Thickness() * Ifc::LengthUnit;
+	const double y = l->Depth() / 2.0f * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double x = l->Width() / 2.0f * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double d = l->Thickness() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	bool doEdgeFillet = l->hasEdgeRadius();
 	bool doFillet = l->hasFilletRadius();
 	double f1 = 0.0f;
 	double f2 = 0.0f;
 	if (doFillet) {
-		f1 = l->FilletRadius() * Ifc::LengthUnit;
+		f1 = l->FilletRadius() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	}
 	if ( doEdgeFillet) {
-		f2 = l->EdgeRadius() * Ifc::LengthUnit;
+		f2 = l->EdgeRadius() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	}
 	if ( x == 0.0f || y == 0.0f || d == 0.0f ) {
-		Ifc::LogMessage("Notice","Skipping zero sized profile:",l->entity);
+		Logger::Message(Logger::LOG_NOTICE,"Skipping zero sized profile:",l->entity);
 		return false;
 	}
 
@@ -235,9 +295,9 @@ bool IfcGeom::convert(const Ifc2x3::IfcLShapeProfileDef::ptr l, TopoDS_Face& fac
 	return IfcGeom::profile_helper(6,coords,doFillet ? 3 : 0,fillets,radii,trsf2d,face);
 }
 bool IfcGeom::convert(const Ifc2x3::IfcCircleProfileDef::ptr l, TopoDS_Face& face) {
-	const double r = l->Radius() * Ifc::LengthUnit;
+	const double r = l->Radius() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	if ( r == 0.0f ) {
-		Ifc::LogMessage("Notice","Skipping zero sized profile:",l->entity);
+		Logger::Message(Logger::LOG_NOTICE,"Skipping zero sized profile:",l->entity);
 		return false;
 	}
 	
@@ -252,11 +312,11 @@ bool IfcGeom::convert(const Ifc2x3::IfcCircleProfileDef::ptr l, TopoDS_Face& fac
 	return IfcGeom::convert_wire_to_face(w,face);
 }
 bool IfcGeom::convert(const Ifc2x3::IfcCircleHollowProfileDef::ptr l, TopoDS_Face& face) {
-	const double r = l->Radius() * Ifc::LengthUnit;
-	const double t = l->WallThickness() * Ifc::LengthUnit;
+	const double r = l->Radius() * IfcGeom::GetValue(GV_LENGTH_UNIT);
+	const double t = l->WallThickness() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	
 	if ( r == 0.0f || t == 0.0f ) {
-		Ifc::LogMessage("Notice","Skipping zero sized profile:",l->entity);
+		Logger::Message(Logger::LOG_NOTICE,"Skipping zero sized profile:",l->entity);
 		return false;
 	}
 	
diff --git a/src/ifcgeom/IfcGeomFunctions.cpp b/src/ifcgeom/IfcGeomFunctions.cpp
index 58e6b3223a..d727d02549 100644
--- a/src/ifcgeom/IfcGeomFunctions.cpp
+++ b/src/ifcgeom/IfcGeomFunctions.cpp
@@ -163,7 +163,7 @@ bool IfcGeom::convert_openings(const Ifc2x3::IfcProduct::ptr entity, const Ifc2x
 		const gp_GTrsf& entity_shape_gtrsf = *(it3->first);
 		TopoDS_Shape entity_shape;
 		if ( entity_shape_gtrsf.Form() == gp_Other ) {
-			Ifc::LogMessage("Warning","Applying non uniform transformation to:",entity->entity);
+			Logger::Message(Logger::LOG_WARNING,"Applying non uniform transformation to:",entity->entity);
 			entity_shape = BRepBuilderAPI_GTransform(entity_shape_unlocated,entity_shape_gtrsf,true).Shape();
 		} else {
 			entity_shape = entity_shape_unlocated.Moved(entity_shape_gtrsf.Trsf());
@@ -175,17 +175,17 @@ bool IfcGeom::convert_openings(const Ifc2x3::IfcProduct::ptr entity, const Ifc2x
 			const TopoDS_Shape& opening_shape_unlocated = IfcGeom::ensure_fit_for_subtraction(*(it4->second),opening_shape_solid);
 			const gp_GTrsf& opening_shape_gtrsf = *(it4->first);
 			if ( opening_shape_gtrsf.Form() == gp_Other ) {
-				Ifc::LogMessage("Warning","Applying non uniform transformation to opening of:",entity->entity);
+				Logger::Message(Logger::LOG_WARNING,"Applying non uniform transformation to opening of:",entity->entity);
 			}
 			const TopoDS_Shape& opening_shape = opening_shape_gtrsf.Form() == gp_Other
 				? BRepBuilderAPI_GTransform(opening_shape_unlocated,opening_shape_gtrsf,true).Shape()
 				: opening_shape_unlocated.Moved(opening_shape_gtrsf.Trsf());
 					
 			double opening_volume, original_shape_volume;
-			if ( Ifc::Verbosity > 1 ) {
+			if ( Logger::Verbosity() >= Logger::LOG_WARNING ) {
 				opening_volume = shape_volume(opening_shape);
 				if ( opening_volume <= ALMOST_ZERO )
-					Ifc::LogMessage("Warning","Empty opening for:",entity->entity);
+					Logger::Message(Logger::LOG_WARNING,"Empty opening for:",entity->entity);
 				original_shape_volume = shape_volume(entity_shape);
 			}
 			
@@ -198,17 +198,17 @@ bool IfcGeom::convert_openings(const Ifc2x3::IfcProduct::ptr entity, const Ifc2x
 				bool is_valid = analyser.IsValid() != 0;
 				if ( is_valid ) {
 					entity_shape = brep_cut;
-					if ( Ifc::Verbosity > 1 ) {
+					if ( Logger::Verbosity() >= Logger::LOG_WARNING ) {
 						const double volume_after_subtraction = shape_volume(entity_shape);
 					
 						if ( ALMOST_THE_SAME(original_shape_volume,volume_after_subtraction) )
-							Ifc::LogMessage("Warning","Subtraction yields unchanged volume:",entity->entity);
+							Logger::Message(Logger::LOG_WARNING,"Subtraction yields unchanged volume:",entity->entity);
 					}
 				} else {
-					Ifc::LogMessage("Error","Invalid result from subtraction:",entity->entity);
+					Logger::Message(Logger::LOG_ERROR,"Invalid result from subtraction:",entity->entity);
 				}
 			} else {
-				Ifc::LogMessage("Error","Failed to process subtraction:",entity->entity);
+				Logger::Message(Logger::LOG_ERROR,"Failed to process subtraction:",entity->entity);
 			}
 
 		}
@@ -274,7 +274,7 @@ bool IfcGeom::convert_openings_fast(const Ifc2x3::IfcProduct::ptr entity, const
 		const gp_GTrsf& entity_shape_gtrsf = *(it3->first);
 		TopoDS_Shape entity_shape;
 		if ( entity_shape_gtrsf.Form() == gp_Other ) {
-			Ifc::LogMessage("Warning","Applying non uniform transformation to:",entity->entity);
+			Logger::Message(Logger::LOG_WARNING,"Applying non uniform transformation to:",entity->entity);
 			entity_shape = BRepBuilderAPI_GTransform(entity_shape_unlocated,entity_shape_gtrsf,true).Shape();
 		} else {
 			entity_shape = entity_shape_unlocated.Moved(entity_shape_gtrsf.Trsf());
@@ -295,7 +295,7 @@ bool IfcGeom::convert_openings_fast(const Ifc2x3::IfcProduct::ptr entity, const
 			// Apparently processing the boolean operation failed or resulted in an invalid result
 			// in which case the original shape without the subtractions is returned instead
 			// we try convert the openings in the original way, one by one.
-			Ifc::LogMessage("Warning","Subtracting combined openings compound failed:",entity->entity);
+			Logger::Message(Logger::LOG_WARNING,"Subtracting combined openings compound failed:",entity->entity);
 			return false;
 		}
 		
@@ -429,7 +429,10 @@ static double deflection_tolerance = 0.001;
 static double wire_creation_tolerance = 0.0001;
 static double minimal_face_area = 0.000001;
 static double point_equality_tolerance = 0.00001;
-static double max_faces_to_sew = 1000;
+static double max_faces_to_sew = -1.0;
+static double ifc_length_unit = 1.0;
+static double ifc_planeangle_unit = -1.0;
+static double force_ccw_face_orientation = -1.0;
 
 void IfcGeom::SetValue(GeomValue var, double value) {
 	switch (var) {
@@ -448,6 +451,15 @@ void IfcGeom::SetValue(GeomValue var, double value) {
 	case GV_MAX_FACES_TO_SEW:
 		max_faces_to_sew = value;
 		break;
+	case GV_LENGTH_UNIT:
+		ifc_length_unit = value;
+		break;
+	case GV_PLANEANGLE_UNIT:
+		ifc_planeangle_unit = value;
+		break;
+	case GV_FORCE_CCW_FACE_ORIENTATION:
+		force_ccw_face_orientation = value;
+		break;
 	default:
 		assert(!"never reach here");
 	}
@@ -465,6 +477,15 @@ double IfcGeom::GetValue(GeomValue var) {
 		return point_equality_tolerance;
 	case GV_MAX_FACES_TO_SEW:
 		return max_faces_to_sew;
+	case GV_LENGTH_UNIT:
+		return ifc_length_unit;
+		break;
+	case GV_PLANEANGLE_UNIT:
+		return ifc_planeangle_unit;
+		break;
+	case GV_FORCE_CCW_FACE_ORIENTATION:
+		return force_ccw_face_orientation;
+		break;
 	}
 	assert(!"never reach here");
 	return 0;
diff --git a/src/ifcgeom/IfcGeomHelpers.cpp b/src/ifcgeom/IfcGeomHelpers.cpp
index acbcf1b363..a229c78957 100644
--- a/src/ifcgeom/IfcGeomHelpers.cpp
+++ b/src/ifcgeom/IfcGeomHelpers.cpp
@@ -91,9 +91,9 @@ bool IfcGeom::convert(const Ifc2x3::IfcCartesianPoint::ptr l, gp_Pnt& point) {
 	IN_CACHE(IfcCartesianPoint,l,gp_Pnt,point)
 	std::vector<double> xyz = l->Coordinates();
 	point = gp_Pnt(
-		xyz.size()     ? (xyz[0]*Ifc::LengthUnit) : 0.0f,
-		xyz.size() > 1 ? (xyz[1]*Ifc::LengthUnit) : 0.0f,
-		xyz.size() > 2 ? (xyz[2]*Ifc::LengthUnit) : 0.0f
+		xyz.size()     ? (xyz[0]*IfcGeom::GetValue(GV_LENGTH_UNIT)) : 0.0f,
+		xyz.size() > 1 ? (xyz[1]*IfcGeom::GetValue(GV_LENGTH_UNIT)) : 0.0f,
+		xyz.size() > 2 ? (xyz[2]*IfcGeom::GetValue(GV_LENGTH_UNIT)) : 0.0f
 	);
 	CACHE(IfcCartesianPoint,l,point)
 	return true;
@@ -113,7 +113,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcVector::ptr l, gp_Vec& v) {
 	IN_CACHE(IfcVector,l,gp_Vec,v)
 	gp_Dir d;
 	IfcGeom::convert(l->Orientation(),d);
-	v = l->Magnitude() * Ifc::LengthUnit * d;
+	v = l->Magnitude() * IfcGeom::GetValue(GV_LENGTH_UNIT) * d;
 	CACHE(IfcVector,l,v)
 	return true;
 }
diff --git a/src/ifcgeom/IfcGeomObjects.cpp b/src/ifcgeom/IfcGeomObjects.cpp
index 49f3433a9a..f3d931a53a 100644
--- a/src/ifcgeom/IfcGeomObjects.cpp
+++ b/src/ifcgeom/IfcGeomObjects.cpp
@@ -51,9 +51,9 @@ bool convert_back_units = false;
 bool use_faster_booleans = false;
 
 int IfcGeomObjects::IfcMesh::addvert(const gp_XYZ& p) {
-	const float X = convert_back_units ? (float) (p.X() / Ifc::LengthUnit) : (float)p.X();
-	const float Y = convert_back_units ? (float) (p.Y() / Ifc::LengthUnit) : (float)p.Y();
-	const float Z = convert_back_units ? (float) (p.Z() / Ifc::LengthUnit) : (float)p.Z();
+	const float X = convert_back_units ? (float) (p.X() / IfcGeom::GetValue(IfcGeom::GV_LENGTH_UNIT)) : (float)p.X();
+	const float Y = convert_back_units ? (float) (p.Y() / IfcGeom::GetValue(IfcGeom::GV_LENGTH_UNIT)) : (float)p.Y();
+	const float Z = convert_back_units ? (float) (p.Z() / IfcGeom::GetValue(IfcGeom::GV_LENGTH_UNIT)) : (float)p.Z();
 	int i = (int) verts.size() / 3;
 	if ( weld_vertices ) {
 		const VertKey key = VertKey(X,std::pair<float,float>(Y,Z));
@@ -71,6 +71,8 @@ int IfcGeomObjects::IfcMesh::addvert(const gp_XYZ& p) {
 bool use_world_coords = false;
 bool use_brep_data = false;
 
+static IfcParse::IfcFile* ifc_file = 0;
+
 IfcGeomObjects::IfcMesh::IfcMesh(int i, const IfcGeom::ShapeList& shapes) {
 	id = i;
 
@@ -102,10 +104,10 @@ IfcGeomObjects::IfcMesh::IfcMesh(int i, const IfcGeom::ShapeList& shapes) {
 
 		// Triangulate the shape
 		try {
-			//BRepTools::Clean(s);
+			// BRepTools::Clean(s);
 			BRepMesh::Mesh(s, IfcGeom::GetValue(IfcGeom::GV_DEFLECTION_TOLERANCE));
 		} catch(...) {
-			Ifc::LogMessage("Error","Failed to triangulate mesh:",Ifc::EntityById(i)->entity);
+			Logger::Message(Logger::LOG_ERROR,"Failed to triangulate mesh:",ifc_file->EntityById(i)->entity);
 			continue;
 		}
 		TopExp_Explorer exp;
@@ -401,7 +403,7 @@ IfcGeomObjects::IfcGeomObject* _get() {
 					IfcGeom::convert_openings(ifc_product,openings,shapes,trsf,opened_shapes);
 				}
 			} catch(...) { 
-				Ifc::LogMessage("Error","Error processing openings for:",ifc_product->entity); 
+				Logger::Message(Logger::LOG_ERROR,"Error processing openings for:",ifc_product->entity); 
 			}
 			if ( use_world_coords ) {
 				for ( IfcGeom::ShapeList::const_iterator it = opened_shapes.begin(); it != opened_shapes.end(); ++ it ) {
@@ -452,7 +454,8 @@ bool IfcGeomObjects::Next() {
 }
 std::vector<IfcGeomObjects::IfcObject*> returned_objects;
 bool IfcGeomObjects::CleanUp() {
-	Ifc::Dispose();
+	// TODO: Correctly implement destructor for IfcFile
+	delete ifc_file;
 	IfcGeom::Cache::Purge();
 	for ( std::vector<IfcGeomObjects::IfcObject*>::const_iterator it = returned_objects.begin();
 		it != returned_objects.end(); 
@@ -465,7 +468,7 @@ bool IfcGeomObjects::CleanUp() {
 const IfcGeomObjects::IfcObject* IfcGeomObjects::GetObject(int id) {
 	IfcObject* ifc_object = 0;
 	try {
-		const IfcEntity& ifc_entity = Ifc::EntityById(id);
+		const IfcParse::IfcEntity& ifc_entity = ifc_file->EntityById(id);
 		if ( ifc_entity->is(Ifc2x3::Type::IfcProduct) ) {
 			Ifc2x3::IfcProduct::ptr ifc_product = reinterpret_pointer_cast<IfcUtil::IfcBaseClass,Ifc2x3::IfcProduct>(ifc_entity);
 			int parent_id = -1;
@@ -488,11 +491,93 @@ const IfcGeomObjects::IfcObject* IfcGeomObjects::GetObject(int id) {
 const IfcGeomObjects::IfcGeomObject* IfcGeomObjects::Get() {
 	return current_geom_obj;
 }
+double UnitPrefixToValue( Ifc2x3::IfcSIPrefix::IfcSIPrefix v ) {
+	if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_EXA   ) return (double) 1e18;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_PETA  ) return (double) 1e15;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_TERA  ) return (double) 1e12;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_GIGA  ) return (double) 1e9;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_MEGA  ) return (double) 1e6;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_KILO  ) return (double) 1e3;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_HECTO ) return (double) 1e2;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_DECA  ) return (double) 1;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_DECI  ) return (double) 1e-1;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_CENTI ) return (double) 1e-2;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_MILLI ) return (double) 1e-3;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_MICRO ) return (double) 1e-6;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_NANO  ) return (double) 1e-9;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_PICO  ) return (double) 1e-12;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_FEMTO ) return (double) 1e-15;
+	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_ATTO  ) return (double) 1e-18;
+	else return 1.0f;
+}
+
+void IfcGeomObjects::InitUnits() {
+	// Set default units, set length to meters, angles to undefined
+	IfcGeom::SetValue(IfcGeom::GV_LENGTH_UNIT,1.0);
+	IfcGeom::SetValue(IfcGeom::GV_PLANEANGLE_UNIT,-1.0);
+	
+	Ifc2x3::IfcUnitAssignment::list unit_assignments = ifc_file->EntitiesByType<Ifc2x3::IfcUnitAssignment>();
+	IfcUtil::IfcAbstractSelect::list units = IfcUtil::IfcAbstractSelect::list();
+	if ( unit_assignments->Size() ) {
+		Ifc2x3::IfcUnitAssignment::ptr unit_assignment = *unit_assignments->begin();
+		units = unit_assignment->Units();
+	}
+	if ( ! units ) {
+		// No units eh... Since tolerances and deflection are specified internally in meters
+		// we will try to find another indication of the model size.
+		Ifc2x3::IfcExtrudedAreaSolid::list extrusions = ifc_file->EntitiesByType<Ifc2x3::IfcExtrudedAreaSolid>();
+		if ( ! extrusions->Size() ) return;
+		double max_height = -1.0f;
+		for ( Ifc2x3::IfcExtrudedAreaSolid::it it = extrusions->begin(); it != extrusions->end(); ++ it ) {
+			const double depth = (*it)->Depth();
+			if ( depth > max_height ) max_height = depth;
+		}
+		if ( max_height > 100.0f ) IfcGeom::SetValue(IfcGeom::GV_LENGTH_UNIT,0.001);
+		return;
+	}
+	try {
+		for ( IfcUtil::IfcAbstractSelect::it it = units->begin(); it != units->end(); ++ it ) {
+			const IfcUtil::IfcAbstractSelect::ptr base = *it;
+			Ifc2x3::IfcSIUnit::ptr unit = Ifc2x3::IfcSIUnit::ptr();
+			double value = 1.0f;
+			if ( base->is(Ifc2x3::Type::IfcConversionBasedUnit) ) {
+				const Ifc2x3::IfcConversionBasedUnit::ptr u = reinterpret_pointer_cast<IfcUtil::IfcAbstractSelect,Ifc2x3::IfcConversionBasedUnit>(base);
+				const Ifc2x3::IfcMeasureWithUnit::ptr u2 = u->ConversionFactor();
+				Ifc2x3::IfcUnit u3 = u2->UnitComponent();
+				if ( u3->is(Ifc2x3::Type::IfcSIUnit) ) {
+					unit = (Ifc2x3::IfcSIUnit*) u3;
+				}
+				Ifc2x3::IfcValue v = u2->ValueComponent();
+				IfcUtil::IfcArgumentSelect* v2 = (IfcUtil::IfcArgumentSelect*) v;
+				const double f = *v2->wrappedValue();
+				value *= f;
+			} else if ( base->is(Ifc2x3::Type::IfcSIUnit) ) {
+				unit = reinterpret_pointer_cast<IfcUtil::IfcAbstractSelect,Ifc2x3::IfcSIUnit>(base);
+			}
+			if ( unit ) {
+				if ( unit->hasPrefix() ) {
+					value *= UnitPrefixToValue(unit->Prefix());
+				}
+				Ifc2x3::IfcUnitEnum::IfcUnitEnum type = unit->UnitType();
+				if ( type == Ifc2x3::IfcUnitEnum::IfcUnit_LENGTHUNIT ) {
+					IfcGeom::SetValue(IfcGeom::GV_LENGTH_UNIT,value);
+				} else if ( type == Ifc2x3::IfcUnitEnum::IfcUnit_PLANEANGLEUNIT ) {
+					IfcGeom::SetValue(IfcGeom::GV_PLANEANGLE_UNIT,value);
+				}
+			}
+		}
+	} catch ( IfcException ex ) {
+		Logger::Message(Logger::LOG_ERROR,ex.what());
+	}
+}
+
 bool IfcGeomObjects::Init(const std::string fn) {
 	return IfcGeomObjects::Init(fn, 0, 0);
 }
 bool _Init() {
-	shapereps = Ifc::EntitiesByType<Ifc2x3::IfcShapeRepresentation>();
+	IfcGeomObjects::InitUnits();
+
+	shapereps = ifc_file->EntitiesByType<Ifc2x3::IfcShapeRepresentation>();
 	if ( ! shapereps ) return false;
 	
 	outer = shapereps->begin();
@@ -506,18 +591,21 @@ bool _Init() {
 	return true;
 }
 bool IfcGeomObjects::Init(const std::string fn, std::ostream* log1, std::ostream* log2) {
-	Ifc::SetOutput(log1,log2);
-	if ( !Ifc::Init(fn) ) return false;
+	Logger::SetOutput(log1,log2);
+	ifc_file = new IfcParse::IfcFile();
+	if ( !ifc_file->Init(fn) ) return false;
 	return _Init();	
 }
 bool IfcGeomObjects::Init(std::istream& f, int len, std::ostream* log1, std::ostream* log2) {
-	Ifc::SetOutput(log1,log2);
-	if ( !Ifc::Init(f, len) ) return false;
+	Logger::SetOutput(log1,log2);
+	ifc_file = new IfcParse::IfcFile();
+	if ( !ifc_file->Init(f, len) ) return false;
 	return _Init();
 }
 bool IfcGeomObjects::Init(void* data, int len) {
-	Ifc::SetOutput(0,0);
-	if ( !Ifc::Init(data, len) ) return false;
+	Logger::SetOutput(0,0);
+	ifc_file = new IfcParse::IfcFile();
+	if ( !ifc_file->Init(data, len) ) return false;
 	return _Init();
 }
 void IfcGeomObjects::Settings(int setting, bool value) {
@@ -538,7 +626,10 @@ void IfcGeomObjects::Settings(int setting, bool value) {
 		use_faster_booleans = value;
 		break;
 	case SEW_SHELLS:
-		Ifc::SewShells = value;
+		IfcGeom::SetValue(IfcGeom::GV_MAX_FACES_TO_SEW,value ? 1000 : -1);
+		break;
+	case IfcGeomObjects::FORCE_CCW_FACE_ORIENTATION:
+		IfcGeom::SetValue(IfcGeom::GV_FORCE_CCW_FACE_ORIENTATION,value ? 1 : -1);
 		break;
 	}
 }
@@ -546,5 +637,5 @@ int IfcGeomObjects::Progress() {
 	return 100 * done / total;
 }
 std::string IfcGeomObjects::GetLog() {
-	return Ifc::GetLog();
+	return Logger::GetLog();
 }
diff --git a/src/ifcgeom/IfcGeomObjects.h b/src/ifcgeom/IfcGeomObjects.h
index 451ac9b0ae..623b174b4b 100644
--- a/src/ifcgeom/IfcGeomObjects.h
+++ b/src/ifcgeom/IfcGeomObjects.h
@@ -94,6 +94,9 @@ namespace IfcGeomObjects {
 	// Specifies whether to compose IfcOpeningElements into a single compound
 	// in order to speed up the processing of opening subtractions.
 	const int FASTER_BOOLEANS = 6;
+	// By default singular faces have no explicitly defined orientation, to
+	// force faces to be defined CounterClockWise set this to true.
+	const int FORCE_CCW_FACE_ORIENTATION = 7;
 
 	// End of settings enumeration.
 
@@ -143,6 +146,7 @@ namespace IfcGeomObjects {
 		IfcGeomObject(int my_id, int p_id, const std::string& n, const std::string& t, const std::string& g, const gp_Trsf& trsf, IfcMesh* m);
 	};
 
+	void InitUnits();
 	bool Init(const std::string fn);
 	bool Init(void* data, int len);
 	bool Init(const std::string fn, std::ostream* log1= 0, std::ostream* log2= 0);
diff --git a/src/ifcgeom/IfcGeomShapes.cpp b/src/ifcgeom/IfcGeomShapes.cpp
index d06a329828..dccb1a5147 100644
--- a/src/ifcgeom/IfcGeomShapes.cpp
+++ b/src/ifcgeom/IfcGeomShapes.cpp
@@ -81,7 +81,7 @@
 bool IfcGeom::convert(const Ifc2x3::IfcExtrudedAreaSolid::ptr l, TopoDS_Shape& shape) {
 	TopoDS_Face face;
 	if ( ! IfcGeom::convert_face(l->SweptArea(),face) ) return false;
-	const double height = l->Depth() * Ifc::LengthUnit;
+	const double height = l->Depth() * IfcGeom::GetValue(GV_LENGTH_UNIT);
 	gp_Trsf trsf;
 	IfcGeom::convert(l->Position(),trsf);
 
@@ -158,11 +158,11 @@ bool IfcGeom::convert(const Ifc2x3::IfcBooleanClippingResult::ptr l, TopoDS_Shap
 
 	const double first_operand_volume = shape_volume(s1);
 	if ( first_operand_volume <= ALMOST_ZERO )
-		Ifc::LogMessage("Warning","Empty solid for:",l->FirstOperand()->entity);
+		Logger::Message(Logger::LOG_WARNING,"Empty solid for:",l->FirstOperand()->entity);
 
 	if ( !IfcGeom::convert_shape(l->SecondOperand(),s2) ) {
 		shape = s1;
-		Ifc::LogMessage("Error","Failed to convert SecondOperand of:",l->entity);
+		Logger::Message(Logger::LOG_ERROR,"Failed to convert SecondOperand of:",l->entity);
 		return true;
 	}
 
@@ -176,7 +176,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcBooleanClippingResult::ptr l, TopoDS_Shap
 	if ( ! is_halfspace ) {
 		const double second_operand_volume = shape_volume(s2);
 		if ( second_operand_volume <= ALMOST_ZERO )
-			Ifc::LogMessage("Warning","Empty solid for:",operand2->entity);
+			Logger::Message(Logger::LOG_WARNING,"Empty solid for:",operand2->entity);
 	}
 
 	bool valid_cut = false;
@@ -211,7 +211,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcBooleanClippingResult::ptr l, TopoDS_Shap
 					if ( is_valid ) {
 						shape = result;
 						valid_cut = true;
-						Ifc::LogMessage("Warning","Slightly nudged the SecondOperand of:",l->entity);
+						Logger::Message(Logger::LOG_WARNING,"Slightly nudged the SecondOperand of:",l->entity);
 					} 
 				}
 			}
@@ -281,9 +281,9 @@ bool IfcGeom::convert(const Ifc2x3::IfcBooleanClippingResult::ptr l, TopoDS_Shap
 	if ( valid_cut ) {
 		const double volume_after_subtraction = shape_volume(shape);
 		if ( ALMOST_THE_SAME(first_operand_volume,volume_after_subtraction) )
-			Ifc::LogMessage("Warning","Subtraction yields unchanged volume:",l->entity);
+			Logger::Message(Logger::LOG_WARNING,"Subtraction yields unchanged volume:",l->entity);
 	} else {
-		Ifc::LogMessage("Error","Failed to process subtraction:",l->entity);
+		Logger::Message(Logger::LOG_ERROR,"Failed to process subtraction:",l->entity);
 		shape = s1;
 	}
 
@@ -294,7 +294,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcConnectedFaceSet::ptr l, TopoDS_Shape& sh
 	Ifc2x3::IfcFace::list faces = l->CfsFaces();
 	bool facesAdded = false;
 	const unsigned int num_faces = faces->Size();
-	if ( Ifc::SewShells && num_faces < GetValue(GV_MAX_FACES_TO_SEW) ) {
+	if ( num_faces < GetValue(GV_MAX_FACES_TO_SEW) ) {
 		BRepOffsetAPI_Sewing builder;
 		builder.SetTolerance(GetValue(GV_POINT_EQUALITY_TOLERANCE));
 		builder.SetMaxTolerance(GetValue(GV_POINT_EQUALITY_TOLERANCE));
@@ -305,7 +305,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcConnectedFaceSet::ptr l, TopoDS_Shape& sh
 				builder.Add(face);
 				facesAdded = true;
 			} else {
-				Ifc::LogMessage("Warning","Invalid face:",(*it)->entity);
+				Logger::Message(Logger::LOG_WARNING,"Invalid face:",(*it)->entity);
 			}
 		}
 		if ( ! facesAdded ) return false;
@@ -326,7 +326,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcConnectedFaceSet::ptr l, TopoDS_Shape& sh
 				builder.Add(compound,face);
 				facesAdded = true;
 			} else {
-				Ifc::LogMessage("Warning","Invalid face:",(*it)->entity);
+				Logger::Message(Logger::LOG_WARNING,"Invalid face:",(*it)->entity);
 			}
 		}
 		if ( ! facesAdded ) return false;
diff --git a/src/ifcgeom/IfcGeomWires.cpp b/src/ifcgeom/IfcGeomWires.cpp
index 692b7922ca..3850b8c9bc 100644
--- a/src/ifcgeom/IfcGeomWires.cpp
+++ b/src/ifcgeom/IfcGeomWires.cpp
@@ -83,62 +83,58 @@
 #include "../ifcgeom/IfcGeom.h"
 
 bool IfcGeom::convert(const Ifc2x3::IfcCompositeCurve::ptr l, TopoDS_Wire& wire) {
-	if ( ! Ifc::hasPlaneAngleUnit ) {
-		Ifc::LogMessage("Warning","Creating a composite curve without unit information:",l->entity);
-		
-        // Temporarily pretend we do have unit information
-        Ifc::hasPlaneAngleUnit = true;
+	if ( IfcGeom::GetValue(GV_PLANEANGLE_UNIT)>0 ) {
+		Logger::Message(Logger::LOG_WARNING,"Creating a composite curve without unit information:",l->entity);
 
-        bool succes_radians = false;
+		// Temporarily pretend we do have unit information
+		IfcGeom::SetValue(GV_PLANEANGLE_UNIT,1.0);
+		
+		bool succes_radians = false;
         bool succes_degrees = false;
         bool use_radians = false;
         bool use_degrees = false;
-		
-        // First try radians
-		Ifc::PlaneAngleUnit = 1.0f;
-        TopoDS_Wire wire_radians, wire_degrees;
+
+		// First try radians
+		TopoDS_Wire wire_radians, wire_degrees;
         try {
 		    succes_radians = IfcGeom::convert(l,wire_radians);
         } catch (...) {}
-		
-        // Now try degrees
-		Ifc::PlaneAngleUnit = 0.0174532925199433f;
+
+		// Now try degrees
+		IfcGeom::SetValue(GV_PLANEANGLE_UNIT,0.0174532925199433);
         try {
 		    succes_degrees = IfcGeom::convert(l,wire_degrees);
         } catch (...) {}
 
 		// Restore to unknown unit state
-		Ifc::PlaneAngleUnit = 1.0f;
-        Ifc::hasPlaneAngleUnit = false;
+		IfcGeom::SetValue(GV_PLANEANGLE_UNIT,-1.0);
 
-        if ( succes_degrees && ! succes_radians ) {
+		if ( succes_degrees && ! succes_radians ) {
 			use_degrees = true;
 		} else if ( succes_radians && ! succes_degrees ) {
-            use_radians = true;
-        } else if ( succes_radians && succes_degrees ) {
-            if ( wire_degrees.Closed() && ! wire_radians.Closed() ) {
-                use_degrees = true;
-            } else if ( wire_radians.Closed() && ! wire_degrees.Closed() ) {
-                use_radians = true;
-            } else {
-                // No heuristic left to prefer the one over the other,
-                // apparently both variants are equally succesful.
-                // The curve might be composed of only straight segments.
-                // Let's go with the wire created using radians as that
-                // at least is a SI unit.
-                use_radians = true;
-            }
-        }
-
-		if ( use_radians ) {
-			Ifc::LogMessage("Notice","Used radians to create composite curve");
-            wire = wire_radians;
-		} else if ( use_degrees ) {
-			Ifc::LogMessage("Notice","Used degrees to create composite curve");
-            wire = wire_degrees;
+			use_radians = true;
+		} else if ( succes_radians && succes_degrees ) {
+			if ( wire_degrees.Closed() && ! wire_radians.Closed() ) {
+				use_degrees = true;
+			} else if ( wire_radians.Closed() && ! wire_degrees.Closed() ) {
+				use_radians = true;
+			} else {
+				// No heuristic left to prefer the one over the other,
+				// apparently both variants are equally succesful.
+				// The curve might be composed of only straight segments.
+				// Let's go with the wire created using radians as that
+				// at least is a SI unit.
+				use_radians = true;
+			}
 		}
 
-		return succes_radians || succes_degrees;
+		if ( use_radians ) {
+			Logger::Message(Logger::LOG_NOTICE,"Used radians to create composite curve");
+            wire = wire_radians;
+		} else if ( use_degrees ) {
+			Logger::Message(Logger::LOG_NOTICE,"Used degrees to create composite curve");
+            wire = wire_degrees;
+		}
 	}
 	Ifc2x3::IfcCompositeCurveSegment::list segments = l->Segments();
 	BRepBuilderAPI_MakeWire w;
@@ -147,7 +143,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcCompositeCurve::ptr l, TopoDS_Wire& wire)
 		const Ifc2x3::IfcCurve::ptr curve = (*it)->ParentCurve();
 		TopoDS_Wire wire2;
 		if ( ! IfcGeom::convert_wire(curve,wire2) ) {
-			Ifc::LogMessage("Error","Failed to convert curve:",curve->entity);
+			Logger::Message(Logger::LOG_ERROR,"Failed to convert curve:",curve->entity);
 			continue;
 		}
 		if ( ! (*it)->SameSense() ) wire2.Reverse();
@@ -166,7 +162,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcCompositeCurve::ptr l, TopoDS_Wire& wire)
 		w.Add(wire2);
 		//last_vertex = w.Vertex();
 		if ( w.Error() != BRepBuilderAPI_WireDone ) {
-			Ifc::LogMessage("Error","Failed to join curve segments:",l->entity);
+			Logger::Message(Logger::LOG_ERROR,"Failed to join curve segments:",l->entity);
 			return false;
 		}
 	}
@@ -176,7 +172,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcCompositeCurve::ptr l, TopoDS_Wire& wire)
 bool IfcGeom::convert(const Ifc2x3::IfcTrimmedCurve::ptr l, TopoDS_Wire& wire) {
 	Ifc2x3::IfcCurve::ptr basis_curve = l->BasisCurve();
 	bool isConic = basis_curve->is(Ifc2x3::Type::IfcConic);
-	double parameterFactor = isConic ? Ifc::PlaneAngleUnit : Ifc::LengthUnit;
+	double parameterFactor = isConic ? IfcGeom::GetValue(GV_PLANEANGLE_UNIT) : IfcGeom::GetValue(GV_LENGTH_UNIT);
 	Handle(Geom_Curve) curve;
 	if ( ! IfcGeom::convert_curve(basis_curve,curve) ) return false;
 	bool trim_cartesian = l->MasterRepresentation() == Ifc2x3::IfcTrimmingPreference::IfcTrimmingPreference_CARTESIAN;
@@ -209,7 +205,7 @@ bool IfcGeom::convert(const Ifc2x3::IfcTrimmedCurve::ptr l, TopoDS_Wire& wire) {
 				BRepBuilderAPI_EdgeError err = e.Error();
 				if ( err == BRepBuilderAPI_PointProjectionFailed ) {
 					w.Add(BRepBuilderAPI_MakeEdge(sense_agreement ? pnt1 : pnt2,sense_agreement ? pnt2 : pnt1));
-					Ifc::LogMessage("Warning","Point projection failed for:",l->entity);
+					Logger::Message(Logger::LOG_WARNING,"Point projection failed for:",l->entity);
 				}
 			} else {
 				w.Add(e.Edge());
diff --git a/src/ifcgeom/IfcRegister.cpp b/src/ifcgeom/IfcRegister.cpp
index 19c56127ca..07e2f63f67 100644
--- a/src/ifcgeom/IfcRegister.cpp
+++ b/src/ifcgeom/IfcRegister.cpp
@@ -33,7 +33,7 @@ using namespace IfcUtil;
 
 bool IfcGeom::convert_shapes(const IfcBaseClass* l, ShapeList& r) {
 #include "IfcRegisterConvertShapes.h"
-	Ifc::LogMessage("Error","No operation defined for:",l->entity);
+	Logger::Message(Logger::LOG_ERROR,"No operation defined for:",l->entity);
 	return false;
 }
 bool IfcGeom::is_shape_collection(const IfcBaseClass* l) {
@@ -45,21 +45,21 @@ const TopoDS_Shape* IfcGeom::convert_shape(const IfcBaseClass* l, TopoDS_Shape&
 	std::map<int,TopoDS_Shape>::const_iterator it = Cache::Shape.find(id);
 	if ( it != Cache::Shape.end() ) { r = it->second; return &(it->second); }
 #include "IfcRegisterConvertShape.h"
-	Ifc::LogMessage("Error","No operation defined for:",l->entity);
+	Logger::Message(Logger::LOG_ERROR,"No operation defined for:",l->entity);
 	return 0;
 }
 bool IfcGeom::convert_wire(const IfcBaseClass* l, TopoDS_Wire& r) {
 #include "IfcRegisterConvertWire.h"
-	Ifc::LogMessage("Error","No operation defined for:",l->entity);
+	Logger::Message(Logger::LOG_ERROR,"No operation defined for:",l->entity);
 	return false;
 }
 bool IfcGeom::convert_face(const IfcBaseClass* l, TopoDS_Face& r) {
 #include "IfcRegisterConvertFace.h"
-	Ifc::LogMessage("Error","No operation defined for:",l->entity);
+	Logger::Message(Logger::LOG_ERROR,"No operation defined for:",l->entity);
 	return false;
 }
 bool IfcGeom::convert_curve(const IfcBaseClass* l, Handle(Geom_Curve)& r) {
 #include "IfcRegisterConvertCurve.h"
-	Ifc::LogMessage("Error","No operation defined for:",l->entity);
+	Logger::Message(Logger::LOG_ERROR,"No operation defined for:",l->entity);
 	return false;
 }
\ No newline at end of file
diff --git a/src/ifcgeom/IfcRegister.h b/src/ifcgeom/IfcRegister.h
index 9d6149960a..0e1d064d07 100644
--- a/src/ifcgeom/IfcRegister.h
+++ b/src/ifcgeom/IfcRegister.h
@@ -38,6 +38,7 @@
 #include <gp_Trsf.hxx>
 #include <gp_Trsf2d.hxx>
 
+#include "../ifcparse/IfcUtil.h"
 #include "../ifcparse/IfcParse.h"
 
 using namespace Ifc2x3;
diff --git a/src/ifcgeom/IfcRegisterConvertShape.h b/src/ifcgeom/IfcRegisterConvertShape.h
index cc68abf227..c84f5fa19d 100644
--- a/src/ifcgeom/IfcRegisterConvertShape.h
+++ b/src/ifcgeom/IfcRegisterConvertShape.h
@@ -7,7 +7,7 @@
 				return &(Cache::Shape[id]); \
 			} \
 		} catch(...) {  } \
-		Ifc::LogMessage("Error","Failed to convert:",l->entity); \
+		Logger::Message(Logger::LOG_ERROR,"Failed to convert:",l->entity); \
 		return false; \
 	}
 #include "IfcRegisterDef.h"
diff --git a/src/ifcgeom/IfcRegisterConvertShapes.h b/src/ifcgeom/IfcRegisterConvertShapes.h
index 0762609895..962cccb203 100644
--- a/src/ifcgeom/IfcRegisterConvertShapes.h
+++ b/src/ifcgeom/IfcRegisterConvertShapes.h
@@ -4,7 +4,7 @@
 		try { \
 			return IfcGeom::convert((T*)l,r); \
 		} catch (...) { } \
-		Ifc::LogMessage("Error","Failed to convert:",l->entity); \
+		Logger::Message(Logger::LOG_ERROR,"Failed to convert:",l->entity); \
 		return false; \
 	}
 #include "IfcRegisterDef.h"
diff --git a/src/ifcparse/IfcCharacterDecoder.cpp b/src/ifcparse/IfcCharacterDecoder.cpp
index 5100c084ab..4f869ddb0f 100644
--- a/src/ifcparse/IfcCharacterDecoder.cpp
+++ b/src/ifcparse/IfcCharacterDecoder.cpp
@@ -1,4 +1,4 @@
-/********************************************************************************
+/********************************************************************************
  *                                                                              *
  * This file is part of IfcOpenShell.                                           *
  *                                                                              *
@@ -87,7 +87,7 @@ void IfcCharacterDecoder::addChar(std::stringstream& s,const UChar32& ch) {
 	s.put(substitution_character);
 #endif
 }
-IfcCharacterDecoder::IfcCharacterDecoder(IfcParse::File* f) {
+IfcCharacterDecoder::IfcCharacterDecoder(IfcParse::IfcSpfStream* f) {
   file = f;
 #ifdef HAVE_ICU
   if (destination) ucnv_close(destination);
diff --git a/src/ifcparse/IfcCharacterDecoder.h b/src/ifcparse/IfcCharacterDecoder.h
index 57a7d76072..e9e8c94dbd 100644
--- a/src/ifcparse/IfcCharacterDecoder.h
+++ b/src/ifcparse/IfcCharacterDecoder.h
@@ -42,7 +42,7 @@ namespace IfcParse {
 
 	class IfcCharacterDecoder {
 	private:
-		IfcParse::File* file;
+		IfcParse::IfcSpfStream* file;
 #ifdef HAVE_ICU
 		static UConverter* destination;
 		static UConverter* converter;
@@ -65,7 +65,7 @@ namespace IfcParse {
 #else
 		static char substitution_character;
 #endif
-		IfcCharacterDecoder(IfcParse::File* file);
+		IfcCharacterDecoder(IfcParse::IfcSpfStream* file);
 		~IfcCharacterDecoder();
 		void dryRun();
 		operator std::string();
diff --git a/src/ifcparse/IfcFile.h b/src/ifcparse/IfcFile.h
index 204687025b..df6021b37b 100644
--- a/src/ifcparse/IfcFile.h
+++ b/src/ifcparse/IfcFile.h
@@ -39,14 +39,14 @@
 //const int BUF_SIZE = (128 * 1024 * 1024);
 
 namespace IfcParse {
-	/// The File class represents a ISO 10303-21 IFC-SPF file in memory.
+	/// The IfcSpfStream class represents a ISO 10303-21 IFC-SPF file in memory.
 	/// The file is interpreted as a sequence of tokens which are lazily
 	/// interpreted only when requested. If the size of the file is
 	/// larger than BUF_SIZE, the file is split into seperate pages, of
 	/// which only one is simultaneously kept in memory, for files
 	/// that define their entities not in a sequential nature, this is
 	/// detrimental for the performance of the parser.
-	class File {
+	class IfcSpfStream {
 	private:
 		std::ifstream stream;
 		char* buffer;
@@ -61,9 +61,9 @@ namespace IfcParse {
 		bool valid;
 		bool eof;
 		unsigned int size;
-		File(const std::string& fn);
-		File(std::istream& f, int len);
-		File(void* data, int len);
+		IfcSpfStream(const std::string& fn);
+		IfcSpfStream(std::istream& f, int len);
+		IfcSpfStream(void* data, int len);
 		/// Returns the character at the cursor 
 		char Peek();
 		/// Returns the character at specified offset
diff --git a/src/ifcparse/IfcParse.cpp b/src/ifcparse/IfcParse.cpp
index e20c2a0215..4e647a5a7c 100644
--- a/src/ifcparse/IfcParse.cpp
+++ b/src/ifcparse/IfcParse.cpp
@@ -1,4 +1,4 @@
-/********************************************************************************
+/********************************************************************************
 *                                                                              *
 * This file is part of IfcOpenShell.                                           *
 *                                                                              *
@@ -33,7 +33,7 @@ using namespace IfcParse;
 // 
 // Opens the file, gets the filesize and reads a chunk in memory
 //
-File::File(const std::string& fn) {
+IfcSpfStream::IfcSpfStream(const std::string& fn) {
 	eof = false;
 	stream.open(fn.c_str(),std::ios_base::binary);
 	if ( ! stream.good() ) {
@@ -56,7 +56,7 @@ File::File(const std::string& fn) {
 	ReadBuffer(false);
 }
 
-File::File(std::istream& f, int l) {
+IfcSpfStream::IfcSpfStream(std::istream& f, int l) {
 	eof = false;
 	size = l;
 #ifdef BUF_SIZE
@@ -70,7 +70,7 @@ File::File(std::istream& f, int l) {
 	len = l;	
 }
 
-File::File(void* data, int l) {
+IfcSpfStream::IfcSpfStream(void* data, int l) {
 	eof = false;
 	size = l;
 #ifdef BUF_SIZE
@@ -83,15 +83,17 @@ File::File(void* data, int l) {
 	len = l;	
 }
 
-void File::Close() {
-	stream.close();
+void IfcSpfStream::Close() {
+#ifdef BUF_SIZE
+	if ( paging ) stream.close();
+#endif
 	delete[] buffer;
 }
 
 //
 // Reads a chunk of BUF_SIZE in memory and increments cursor if requested
 //
-void File::ReadBuffer(bool inc) {
+void IfcSpfStream::ReadBuffer(bool inc) {
 #ifdef BUF_SIZE
 	if ( inc ) {
 		offset += len;
@@ -108,12 +110,17 @@ void File::ReadBuffer(bool inc) {
 	len = (unsigned int) stream.gcount();
 	eof = len == 0;
 	ptr = 0;
+#ifdef BUF_SIZE
+	if (!paging) stream.close();
+#else
+	stream.close();
+#endif
 }
 
 //
 // Seeks an arbitrary position in the file
 //
-void File::Seek(unsigned int o) {
+void IfcSpfStream::Seek(unsigned int o) {
 #ifdef BUF_SIZE
 	if ( !paging ) {
 #endif
@@ -135,14 +142,14 @@ void File::Seek(unsigned int o) {
 //
 // Returns the character at the cursor
 //
-char File::Peek() {
+char IfcSpfStream::Peek() {
 	return buffer[ptr];
 }
 
 //
 // Returns the character at specified offset
 //
-char File::Read(unsigned int o) {
+char IfcSpfStream::Read(unsigned int o) {
 #ifdef BUF_SIZE
 	if ( ! paging ) {
 #endif
@@ -161,7 +168,7 @@ char File::Read(unsigned int o) {
 //
 // Returns the cursor position
 //
-unsigned int File::Tell() {
+unsigned int IfcSpfStream::Tell() {
 #ifdef BUF_SIZE
 	return offset + ptr;
 #else
@@ -172,7 +179,7 @@ unsigned int File::Tell() {
 //
 // Increments cursor and reads new chunk if necessary
 //
-void File::Inc() {
+void IfcSpfStream::Inc() {
 	if ( ++ptr == len ) { 
 #ifdef BUF_SIZE
 		if ( paging ) ReadBuffer();
@@ -184,13 +191,14 @@ void File::Inc() {
 		}
 #endif
 	}
-	const char current = File::Peek();
-	if ( current == '\n' || current == '\r' ) File::Inc();
+	const char current = IfcSpfStream::Peek();
+	if ( current == '\n' || current == '\r' ) IfcSpfStream::Inc();
 }
 
-Tokens::Tokens(IfcParse::File *f) {
+Tokens::Tokens(IfcParse::IfcSpfStream *s, IfcParse::IfcFile* f) {
 	file = f;
-	decoder = new IfcCharacterDecoder(f);
+	stream = s;
+	decoder = new IfcCharacterDecoder(s);
 }
 
 Tokens::~Tokens() {
@@ -202,38 +210,38 @@ Tokens::~Tokens() {
 //
 Token Tokens::Next() {
 
-	if ( file->eof ) return TokenPtr();
+	if ( stream->eof ) return TokenPtr();
 
 	char c;
 
 	// Trim whitespace
-	while ( !file->eof ) {
-		c = file->Peek();
-		if ( (c == ' ' || c == '\r' || c == '\n' || c == '\t' ) ) file->Inc();
+	while ( !stream->eof ) {
+		c = stream->Peek();
+		if ( (c == ' ' || c == '\r' || c == '\n' || c == '\t' ) ) stream->Inc();
 		else break;
 	}
 
-	if ( file->eof ) return TokenPtr();
-	unsigned int pos = file->Tell();
+	if ( stream->eof ) return TokenPtr();
+	unsigned int pos = stream->Tell();
 
 	bool inString = false;
 	bool inComment = false;
 
 	// If the cursor is at [()=,;$*] we know token consists of single char
 	if ( c == '(' || c == ')' || c == '=' || c == ',' || c == ';' || c == '$' || c == '*' ) {
-		file->Inc();
+		stream->Inc();
 		return TokenPtr(c);
 	}
 
 	int len = 0;
 
 	char p = 0;
-	while ( ! file->eof ) {
+	while ( ! stream->eof ) {
 
 		// Read character and increment pointer if not starting a new token
-		char c = file->Peek();
+		char c = stream->Peek();
 		if ( len && (!inString || inComment) && (c == '(' || c == ')' || c == '=' || c == ',' || c == ';' ) ) break;
-		file->Inc();
+		stream->Inc();
 
 		// Skip whitespace if not in comment or string
 		if ( !inComment && !inString && (c == ' ' || c == '\r' || c == '\n' || c == '\t' ) ) continue;
@@ -247,7 +255,7 @@ Token Tokens::Next() {
 
 		p = c;
 	}
-	if ( len ) return TokenPtr(pos);
+	if ( len ) return TokenPtr(this,pos);
 	else return TokenPtr();
 }
 
@@ -256,18 +264,18 @@ Token Tokens::Next() {
 // Omits whitespace and comments
 //
 std::string Tokens::TokenString(unsigned int offset) {
-	const bool was_eof = file->eof;
-	unsigned int old_offset = file->Tell();
-	file->Seek(offset);
+	const bool was_eof = stream->eof;
+	unsigned int old_offset = stream->Tell();
+	stream->Seek(offset);
 	bool inString = false;
 	bool inComment = false;
 	std::string buffer;
 	buffer.reserve(128);
 	char p = 0;
-	while ( ! file->eof ) {
-		char c = file->Peek();
+	while ( ! stream->eof ) {
+		char c = stream->Peek();
 		if ( buffer.size() && (!inString || inComment) && (c == '(' || c == ')' || c == '=' || c == ',' || c == ';' ) ) break;
-		file->Inc();
+		stream->Inc();
 		if ( !inComment && !inString && (c == ' ' || c == '\r' || c == '\n' || c == '\t' ) ) continue;
 		if ( !inComment ) buffer.push_back(c);
 		if ( inComment && p == '*' && c == '/' ) inComment = false;
@@ -275,8 +283,8 @@ std::string Tokens::TokenString(unsigned int offset) {
 		else if ( !inComment && c == '\'' ) return *decoder;
 		p = c;
 	}
-	if ( was_eof ) file->eof = true;
-	else file->Seek(old_offset);
+	if ( was_eof ) stream->eof = true;
+	else stream->Seek(old_offset);
 	return buffer;
 }
 
@@ -284,33 +292,32 @@ std::string Tokens::TokenString(unsigned int offset) {
 // Functions for creating Tokens from an arbitary file offset.
 // The first 4 bits are reserved for Tokens of type ()=,;$*
 //
-Token IfcParse::TokenPtr(unsigned int offset) { return offset + 128; }
-Token IfcParse::TokenPtr(char c) { return c; }
-Token IfcParse::TokenPtr() { return 0; }
+Token IfcParse::TokenPtr(Tokens* tokens, unsigned int offset) { return Token(tokens,offset); }
+Token IfcParse::TokenPtr(char c) { return Token((Tokens*)0,(unsigned) c); }
+Token IfcParse::TokenPtr() { return Token((Tokens*)0,0); }
 
 //
 // Functions to convert Tokens to binary data
 //
-unsigned int TokenFunc::Offset(Token t) { return t - 128; }
-bool TokenFunc::startsWith(Token t, char c) {
-	return Ifc::file->Read(Offset(t)) == c;
+bool TokenFunc::startsWith(const Token& t, char c) {
+	return t.first->stream->Read(t.second) == c;
 }
-bool TokenFunc::isOperator(Token t, char op) {
-	return (t < 128) && (!op || op == t);
+bool TokenFunc::isOperator(const Token& t, char op) {
+	return (!t.first) && (!op || op == t.second);
 }
-bool TokenFunc::isIdentifier(Token t) {
+bool TokenFunc::isIdentifier(const Token& t) {
 	return ! isOperator(t) && startsWith(t, '#');
 }
-bool TokenFunc::isString(Token t) {
+bool TokenFunc::isString(const Token& t) {
 	return ! isOperator(t) && startsWith(t, '\'');
 }
-bool TokenFunc::isEnumeration(Token t) {
+bool TokenFunc::isEnumeration(const Token& t) {
 	return ! isOperator(t) && startsWith(t, '.');
 }
-bool TokenFunc::isDatatype(Token t) {
+bool TokenFunc::isDatatype(const Token& t) {
 	return ! isOperator(t) && startsWith(t, 'I');
 }
-int TokenFunc::asInt(Token t) {
+int TokenFunc::asInt(const Token& t) {
 	const std::string str = asString(t);
 	// In case of an ENTITY_INSTANCE_NAME skip the leading #
 	const char* start = str.c_str() + (isIdentifier(t) ? 1 : 0);
@@ -319,31 +326,31 @@ int TokenFunc::asInt(Token t) {
 	if ( start == end ) throw IfcException("Token is not an integer or identifier");
 	return (int) result;
 }
-bool TokenFunc::asBool(Token t) {
+bool TokenFunc::asBool(const Token& t) {
 	const std::string str = asString(t);
 	return str == "T";
 }
-double TokenFunc::asFloat(Token t) {
+double TokenFunc::asFloat(const Token& t) {
 	const std::string str = asString(t);
 	return (double) atof(str.c_str());
 }
-std::string TokenFunc::asString(Token t) {
+std::string TokenFunc::asString(const Token& t) {
 	if ( isOperator(t,'$') ) return "";
 	else if ( isOperator(t) ) throw IfcException("Token is not a string");
-	std::string str = Ifc::tokens->TokenString(t - 128);
+	std::string str = t.first->TokenString(t.second);
 	return isString(t) || isEnumeration(t) ? str.substr(1,str.size()-2) : str;
 }
-std::string TokenFunc::toString(Token t) {
-	if ( isOperator(t) ) return std::string ( (char*) &t, 1 );
-	else return Ifc::tokens->TokenString(t - 128);
+std::string TokenFunc::toString(const Token& t) {
+	if ( isOperator(t) ) return std::string ( (char*) &t.second	, 1 );
+	else return t.first->TokenString(t.second);
 }
 
 
-TokenArgument::TokenArgument(Token t) {
+TokenArgument::TokenArgument(const Token& t) {
 	token = t;
 }
 
-EntityArgument::EntityArgument(Ifc2x3::Type::Enum ty, Token t) {
+EntityArgument::EntityArgument(Ifc2x3::Type::Enum ty, const Token& t) {
 	entity = new IfcUtil::IfcArgumentSelect(ty,new TokenArgument(t));
 }
 
@@ -352,10 +359,11 @@ EntityArgument::EntityArgument(Ifc2x3::Type::Enum ty, Token t) {
 // Aditionally, stores the ids (i.e. #[\d]+) in a vector
 //
 ArgumentList::ArgumentList(Tokens* t, std::vector<unsigned int>& ids) {
-	while( Token next = t->Next() ) {
-		if ( TokenFunc::isOperator(next,',') ) continue;
-		if ( TokenFunc::isOperator(next,')') ) break;
-		if ( TokenFunc::isOperator(next,'(') ) Push( new ArgumentList(t,ids) );
+	Token next = t->Next();
+	while( next.second || next.first ) {
+		if ( TokenFunc::isOperator(next,',') ) {}
+		else if ( TokenFunc::isOperator(next,')') ) break;
+		else if ( TokenFunc::isOperator(next,'(') ) Push( new ArgumentList(t,ids) );
 		else {
 			if ( TokenFunc::isIdentifier(next) ) ids.push_back(TokenFunc::asInt(next));
 			if ( TokenFunc::isDatatype(next) ) {
@@ -363,13 +371,14 @@ ArgumentList::ArgumentList(Tokens* t, std::vector<unsigned int>& ids) {
 				try {
 					Push ( new EntityArgument(Ifc2x3::Type::FromString(TokenFunc::asString(next)),t->Next()) );
 				} catch ( IfcException& e ) {
-					Ifc::LogMessage("Error",e.what());
+					Logger::Message(Logger::LOG_ERROR,e.what());
 				}
 				t->Next();
 			} else {
 				Push ( new TokenArgument(next) );
 			}
 		}
+		next = t->Next();
 	}
 }
 
@@ -454,11 +463,7 @@ TokenArgument::operator std::string() const { return TokenFunc::asString(token);
 TokenArgument::operator std::vector<double>() const { throw IfcException("Argument is not a list of floats"); }
 TokenArgument::operator std::vector<int>() const { throw IfcException("Argument is not a list of ints"); }
 TokenArgument::operator std::vector<std::string>() const { throw IfcException("Argument is not a list of strings"); }
-TokenArgument::operator IfcUtil::IfcSchemaEntity() const { return Ifc::EntityById(TokenFunc::asInt(token)); }
-/*TokenArgument::operator IfcUtil::IfcAbstractSelect::ptr() const {
-//TODO Fix memory leak
-return new IfcUtil::IfcEntitySelect(*this); 
-}*/
+TokenArgument::operator IfcUtil::IfcSchemaEntity() const { return token.first->file->EntityById(TokenFunc::asInt(token)); }
 TokenArgument::operator IfcEntities() const { throw IfcException("Argument is not a list of entities"); }
 unsigned int TokenArgument::Size() const { return 1; }
 ArgumentPtr TokenArgument::operator [] (unsigned int i) const { throw IfcException("Argument is not a list of arguments"); }
@@ -496,19 +501,21 @@ EntityArgument::~EntityArgument() { delete entity; }
 //
 // Reads an Entity from the list of Tokens
 //
-Entity::Entity(unsigned int i, Tokens* t) {
-	Token datatype = t->Next();
+Entity::Entity(unsigned int i, IfcFile* f) { //: file(f) {
+	file = f;
+	Token datatype = f->tokens->Next();
 	if ( ! TokenFunc::isDatatype(datatype)) throw IfcException("Unexpected token while parsing entity");
 	_type = Ifc2x3::Type::FromString(TokenFunc::asString(datatype));
 	_id = i;
 	args = ArgumentPtr();
-	offset = TokenFunc::Offset(datatype);
+	offset = datatype.second;
 }
 
 //
 // Reads an Entity from the list of Tokens at the specified offset in the file
 //
-Entity::Entity(unsigned int i, Tokens* t, unsigned int o) {
+Entity::Entity(unsigned int i, IfcFile* f, unsigned int o) { // : file(f) {
+	file = f;
 	std::vector<unsigned int> ids;
 	_id = i;
 	offset = o;
@@ -539,16 +546,16 @@ unsigned int Entity::getArgumentCount() {
 //
 void Entity::Load(std::vector<unsigned int>& ids, bool seek) {
 	if ( seek ) {
-		Ifc::file->Seek(offset);
-		Token datatype = Ifc::tokens->Next();
+		file->tokens->stream->Seek(offset);
+		Token datatype = file->tokens->Next();
 		if ( ! TokenFunc::isDatatype(datatype)) throw IfcException("Unexpected token while parsing entity");
 		_type = Ifc2x3::Type::FromString(TokenFunc::asString(datatype));
 	}
-	Token open = Ifc::tokens->Next();
-	args = new ArgumentList(Ifc::tokens, ids);
-	unsigned int old_offset = Ifc::file->Tell();
-	Token semilocon = Ifc::tokens->Next();
-	if ( ! TokenFunc::isOperator(semilocon,';') ) Ifc::file->Seek(old_offset);
+	Token open = file->tokens->Next();
+	args = new ArgumentList(file->tokens, ids);
+	unsigned int old_offset = file->tokens->stream->Tell();
+	Token semilocon = file->tokens->Next();
+	if ( ! TokenFunc::isOperator(semilocon,';') ) file->tokens->stream->Seek(old_offset);
 }
 
 Ifc2x3::Type::Enum Entity::type() const {
@@ -589,7 +596,7 @@ Entity::~Entity() {
 //
 IfcEntities Entity::getInverse(Ifc2x3::Type::Enum c) {
 	IfcEntities l = IfcEntities(new IfcEntityList());
-	IfcEntities all = Ifc::EntitiesByReference(_id);
+	IfcEntities all = file->EntitiesByReference(_id);
 	if ( ! all ) return l;
 	for( IfcEntityList::it it = all->begin(); it != all->end();++  it  ) {
 		if ( c == Ifc2x3::Type::ALL || (*it)->is(c) ) {
@@ -612,44 +619,55 @@ IfcEntities Entity::getInverse(Ifc2x3::Type::Enum c, int i, const std::string& a
 bool Entity::is(Ifc2x3::Type::Enum v) const {	return _type == v; }
 unsigned int Entity::id() { return _id; }
 
+IfcFile::IfcFile() {
+	file = 0;
+	lastId = 0;
+	tokens = 0;
+	MaxId = 0;
+}
+
 //
 // Parses the IFC file in fn
 // Creates the maps
 // Gets the unit definitins from the file
 //
-bool Ifc::Init(const std::string& fn) {
-	return Ifc::Init(new File(fn));
+bool IfcFile::Init(const std::string& fn) {
+	return IfcFile::Init(new IfcSpfStream(fn));
 }
-bool Ifc::Init(std::istream& f, int len) {
-	return Ifc::Init(new File(f,len));
+bool IfcFile::Init(std::istream& f, int len) {
+	return IfcFile::Init(new IfcSpfStream(f,len));
 }
-bool Ifc::Init(void* data, int len) {
-	return Ifc::Init(new File(data,len));
+bool IfcFile::Init(void* data, int len) {
+	return IfcFile::Init(new IfcSpfStream(data,len));
 }
-bool Ifc::Init(IfcParse::File* f) {
+bool IfcFile::Init(IfcParse::IfcSpfStream* f) {
 	Ifc2x3::InitStringMap();
 	file = f;
 	if ( ! file->valid ) return false;
-	tokens = new Tokens (file);
-	Token token = 0;
-	Token previous = 0;
+	tokens = new Tokens (file,this);
+	Token token = TokenPtr();
+	Token previous = TokenPtr();
 	unsigned int currentId = 0;
 	lastId = 0;
 	int x = 0;
 	EntityPtr e;
 	IfcUtil::IfcSchemaEntity entity = 0; 
-	if ( log1 ) (*log1) << "Scanning file..." << std::endl;
+	Logger::Status("Scanning file...");
 	while ( ! file->eof ) {
 		if ( currentId ) {
 			try {
-				e = new Entity(currentId,tokens);
+				e = new Entity(currentId,this);
 				entity = Ifc2x3::SchemaEntity(e);
 			} catch (IfcException ex) {
 				currentId = 0;
-				Ifc::LogMessage("Error",ex.what());
+				Logger::Message(Logger::LOG_ERROR,ex.what());
 				continue;
 			}
-			if ( log1 && !((++x)%1000) ) (*log1) << "\r#" << currentId << "         " << std::flush;
+			// Update the status after every 1000 instances parsed
+			if ( !((++x)%1000) ) {
+				std::stringstream ss; ss << "\r#" << currentId;
+				Logger::Status(ss.str());
+			}
 			if ( entity->is(Ifc2x3::Type::IfcRoot) ) {
 				Ifc2x3::IfcRoot::ptr ifc_root = (Ifc2x3::IfcRoot::ptr) entity;
 				try {
@@ -657,11 +675,11 @@ bool Ifc::Init(IfcParse::File* f) {
 					if ( byguid.find(guid) != byguid.end() ) {
 						std::stringstream ss;
 						ss << "Overwriting entity with guid " << guid;
-						Ifc::LogMessage("Warning",ss.str());
+						Logger::Message(Logger::LOG_WARNING,ss.str());
 					}
 					byguid[guid] = ifc_root;
 				} catch (IfcException ex) {
-					Ifc::LogMessage("Error",ex.what());
+					Logger::Message(Logger::LOG_ERROR,ex.what());
 				}
 			}
 			Ifc2x3::Type::Enum ty = entity->type();
@@ -677,16 +695,16 @@ bool Ifc::Init(IfcParse::File* f) {
 			if ( byid.find(currentId) != byid.end() ) {
 				std::stringstream ss;
 				ss << "Overwriting entity with id " << currentId;
-				Ifc::LogMessage("Warning",ss.str());
+				Logger::Message(Logger::LOG_WARNING,ss.str());
 			}
 			byid[currentId] = entity;
 			currentId = 0;
 		} else {
 			try { token = tokens->Next(); }
-			catch (... ) { token = 0; }
+			catch (... ) { token = TokenPtr(); }
 		}
-		if ( ! token ) break;
-		if ( previous && TokenFunc::isIdentifier(previous) ) {
+		if ( ! (token.second || token.first) ) break;
+		if ( (previous.second || previous.first) && TokenFunc::isIdentifier(previous) ) {
 			int id = TokenFunc::asInt(previous);
 			if ( TokenFunc::isOperator(token,'=') ) {
 				currentId = id;
@@ -701,89 +719,32 @@ bool Ifc::Init(IfcParse::File* f) {
 		}
 		previous = token;
 	}
-
-	if ( log1 ) (*log1) << "\rDone scanning file   " << std::endl;
-
-    hasPlaneAngleUnit = false;
-	Ifc2x3::IfcUnitAssignment::list unit_assignments = EntitiesByType<Ifc2x3::IfcUnitAssignment>();
-	IfcUtil::IfcAbstractSelect::list units = IfcUtil::IfcAbstractSelect::list();
-	if ( unit_assignments->Size() ) {
-		Ifc2x3::IfcUnitAssignment::ptr unit_assignment = *unit_assignments->begin();
-		units = unit_assignment->Units();
-	}
-	if ( ! units ) {
-		// No units eh... Since tolerances and deflection are specified internally in meters
-		// we will try to find another indication of the model size.
-		Ifc2x3::IfcExtrudedAreaSolid::list extrusions = EntitiesByType<Ifc2x3::IfcExtrudedAreaSolid>();
-		if ( ! extrusions->Size() ) return true;
-		double max_height = -1.0f;
-		for ( Ifc2x3::IfcExtrudedAreaSolid::it it = extrusions->begin(); it != extrusions->end(); ++ it ) {
-			const double depth = (*it)->Depth();
-			if ( depth > max_height ) max_height = depth;
-		}
-		if ( max_height > 100.0f ) Ifc::LengthUnit = 0.001f;
-		return true;
-	}
-	try {
-		for ( IfcUtil::IfcAbstractSelect::it it = units->begin(); it != units->end(); ++ it ) {
-			const IfcUtil::IfcAbstractSelect::ptr base = *it;
-			Ifc2x3::IfcSIUnit::ptr unit = Ifc2x3::IfcSIUnit::ptr();
-			double value = 1.0f;
-			if ( base->is(Ifc2x3::Type::IfcConversionBasedUnit) ) {
-				const Ifc2x3::IfcConversionBasedUnit::ptr u = reinterpret_pointer_cast<IfcUtil::IfcAbstractSelect,Ifc2x3::IfcConversionBasedUnit>(base);
-				const Ifc2x3::IfcMeasureWithUnit::ptr u2 = u->ConversionFactor();
-				Ifc2x3::IfcUnit u3 = u2->UnitComponent();
-				if ( u3->is(Ifc2x3::Type::IfcSIUnit) ) {
-					unit = (Ifc2x3::IfcSIUnit*) u3;
-				}
-				Ifc2x3::IfcValue v = u2->ValueComponent();
-				IfcUtil::IfcArgumentSelect* v2 = (IfcUtil::IfcArgumentSelect*) v;
-				const double f = *v2->wrappedValue();
-				value *= f;
-			} else if ( base->is(Ifc2x3::Type::IfcSIUnit) ) {
-				unit = reinterpret_pointer_cast<IfcUtil::IfcAbstractSelect,Ifc2x3::IfcSIUnit>(base);
-			}
-			if ( unit ) {
-				if ( unit->hasPrefix() ) {
-					value *= UnitPrefixToValue(unit->Prefix());
-				}
-				Ifc2x3::IfcUnitEnum::IfcUnitEnum type = unit->UnitType();
-				if ( type == Ifc2x3::IfcUnitEnum::IfcUnit_LENGTHUNIT ) {
-					Ifc::LengthUnit = value;
-				} else if ( type == Ifc2x3::IfcUnitEnum::IfcUnit_PLANEANGLEUNIT ) {
-					Ifc::PlaneAngleUnit = value;
-					Ifc::hasPlaneAngleUnit = true;
-				}
-			}
-		}
-	} catch ( IfcException ex ) {
-		Ifc::LogMessage("Error",ex.what());
-	}
+	Logger::Status("\rDone scanning file   ");
 	return true;
 }
 
-IfcEntities Ifc::EntitiesByType(Ifc2x3::Type::Enum t) {
+IfcEntities IfcFile::EntitiesByType(Ifc2x3::Type::Enum t) {
 	MapEntitiesByType::const_iterator it = bytype.find(t);
 	return (it == bytype.end()) ? IfcEntities() : it->second;
 }
-IfcEntities Ifc::EntitiesByReference(int t) {
+IfcEntities IfcFile::EntitiesByReference(int t) {
 	MapEntitiesByRef::const_iterator it = byref.find(t);
 	return (it == byref.end()) ? IfcEntities() : it->second;
 }
-IfcUtil::IfcSchemaEntity Ifc::EntityById(int id) {
+IfcUtil::IfcSchemaEntity IfcFile::EntityById(int id) {
 	MapEntityById::const_iterator it = byid.find(id);
 	if ( it == byid.end() ) {
 		MapOffsetById::const_iterator it2 = offsets.find(id);
 		if ( it2 == offsets.end() ) throw IfcException("Entity not found");
 		const unsigned int offset = (*it2).second;
-		EntityPtr e = EntityPtr(new Entity(id,Ifc::tokens,offset));
+		EntityPtr e = EntityPtr(new Entity(id,this,offset));
 		IfcUtil::IfcSchemaEntity entity = Ifc2x3::SchemaEntity(e);
 		byid[id] = entity;
 		return entity;
 	}
 	return it->second;
 }
-Ifc2x3::IfcRoot::ptr Ifc::EntityByGuid(const std::string& guid) {
+Ifc2x3::IfcRoot::ptr IfcFile::EntityByGuid(const std::string& guid) {
 	MapEntityByGuid::const_iterator it = byguid.find(guid);
 	if ( it == byguid.end() ) {
 		throw IfcException("Entity not found");
@@ -796,77 +757,19 @@ IfcException::IfcException(std::string e) { error = e; }
 IfcException::~IfcException() throw () {}
 const char* IfcException::what() const throw() { return error.c_str(); }
 
-void Ifc::Dispose() {
+// FIXME: Test destructor to delete entity and arg allocations
+IfcFile::~IfcFile() {
 	for( MapEntityById::const_iterator it = byid.begin(); it != byid.end(); ++ it ) {
 		delete it->second->entity;
 		delete it->second;
 	}
-	bytype.clear();
-	byid.clear();
-	byref.clear();
-	file->Close();
 	delete file;
 	delete tokens;
-	offsets.clear();
-	log_stream.str("");
 }
 
-double UnitPrefixToValue( Ifc2x3::IfcSIPrefix::IfcSIPrefix v ) {
-	if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_EXA   ) return (double) 1e18;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_PETA  ) return (double) 1e15;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_TERA  ) return (double) 1e12;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_GIGA  ) return (double) 1e9;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_MEGA  ) return (double) 1e6;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_KILO  ) return (double) 1e3;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_HECTO ) return (double) 1e2;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_DECA  ) return (double) 1;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_DECI  ) return (double) 1e-1;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_CENTI ) return (double) 1e-2;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_MILLI ) return (double) 1e-3;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_MICRO ) return (double) 1e-6;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_NANO  ) return (double) 1e-9;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_PICO  ) return (double) 1e-12;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_FEMTO ) return (double) 1e-15;
-	else if ( v == Ifc2x3::IfcSIPrefix::IfcSIPrefix_ATTO  ) return (double) 1e-18;
-	else return 1.0f;
-}
-void Ifc::SetOutput(std::ostream* l1, std::ostream* l2) { 
-	log1 = l1; 
-	log2 = l2; 
-	if ( ! log2 ) {
-		log2 = &log_stream;
-	}
-}
-void Ifc::LogMessage(const std::string& type, const std::string& message, const IfcAbstractEntityPtr entity) {
-	if ( log2 ) {
-		(*log2) << "[" << type << "] " << message << std::endl;
-		if ( entity ) (*log2) << entity->toString() << std::endl;
-	}
-}
-std::string Ifc::GetLog() {
-	return log_stream.str();
-}
-MapEntityById::const_iterator Ifc::First() {
+MapEntityById::const_iterator IfcFile::begin() const {
 	return byid.begin();
 }
-MapEntityById::const_iterator Ifc::Last() {
+MapEntityById::const_iterator IfcFile::end() const {
 	return byid.end();
 }
-
-File* Ifc::file = 0;
-std::ostream* Ifc::log1 = 0;
-std::ostream* Ifc::log2 = 0;
-unsigned int Ifc::lastId = 0;
-Tokens* Ifc::tokens = 0;
-double Ifc::LengthUnit = 1.0f;
-double Ifc::PlaneAngleUnit = 1.0f;
-bool Ifc::hasPlaneAngleUnit = false;
-bool Ifc::SewShells = false;
-int Ifc::CircleSegments = 32;
-MapEntitiesByType Ifc::bytype;
-MapEntityById Ifc::byid;
-MapEntityByGuid Ifc::byguid;
-MapEntitiesByRef Ifc::byref;
-MapOffsetById Ifc::offsets;
-std::stringstream Ifc::log_stream;
-int Ifc::Verbosity = 2;
diff --git a/src/ifcparse/IfcParse.h b/src/ifcparse/IfcParse.h
index ec00f27394..19bde845f0 100644
--- a/src/ifcparse/IfcParse.h
+++ b/src/ifcparse/IfcParse.h
@@ -1,4 +1,4 @@
-/********************************************************************************
+/********************************************************************************
 *                                                                              *
 * This file is part of IfcOpenShell.                                           *
 *                                                                              *
@@ -47,56 +47,59 @@ namespace IfcParse {
 
 	class Entity;
 	class Entities;
+	class IfcFile;
 	typedef Entity* EntityPtr;
 	typedef SHARED_PTR<Entities> EntitiesPtr;
 
-	typedef unsigned int Token;
+	class Tokens;
+	typedef std::pair<Tokens*,unsigned> Token;
 
 	/// Provides functions to convert Tokens to binary data
 	/// Tokens are merely offsets to where they can be read in the file
 	class TokenFunc {
 	private:
-		static bool startsWith(Token t, char c);
+		static bool startsWith(const Token& t, char c);
 	public:
 		/// Returns the offset at which the token is read from the file
-		static unsigned int Offset(Token t);
+		// static unsigned int Offset(const Token& t);
 		/// Returns whether the token can be interpreted as a string
-		static bool isString(Token t);
+		static bool isString(const Token& t);
 		/// Returns whether the token can be interpreted as an identifier
-		static bool isIdentifier(Token t);
+		static bool isIdentifier(const Token& t);
 		/// Returns whether the token can be interpreted as an syntactical operator
-		static bool isOperator(Token t, char op = 0);
+		static bool isOperator(const Token& t, char op = 0);
 		/// Returns whether the token can be interpreted as an enumerated value
-		static bool isEnumeration(Token t);
+		static bool isEnumeration(const Token& t);
 		/// Returns whether the token can be interpreted as an datatype name
-		static bool isDatatype(Token t);
+		static bool isDatatype(const Token& t);
 		/// Returns the token interpreted as an integer
-		static int asInt(Token t);
+		static int asInt(const Token& t);
 		/// Returns the token interpreted as an boolean (.T. or .F.)
-		static bool asBool(Token t);
+		static bool asBool(const Token& t);
 		/// Returns the token as a floating point number
-		static double asFloat(Token t);
+		static double asFloat(const Token& t);
 		/// Returns the token as a string (without the dot or apostrophe)
-		static std::string asString(Token t);
+		static std::string asString(const Token& t);
 		/// Returns a string representation of the token (including the dot or apostrophe)
-		static std::string toString(Token t);
+		static std::string toString(const Token& t);
 	};
 
 	//
 	// Functions for creating Tokens from an arbitary file offset
 	// The first 4 bits are reserved for Tokens of type ()=,;$*
 	//
-	Token TokenPtr(unsigned int offset);
+	Token TokenPtr(Tokens* tokens, unsigned int offset);
 	Token TokenPtr(char c);	
 	Token TokenPtr();
 
-	/// A stream of tokens to be read from a File.
+	/// A stream of tokens to be read from a IfcSpfStream.
 	class Tokens {
 	private:
-		File* file;
 		IfcCharacterDecoder* decoder;
 	public:
-		Tokens(File* f);
+		IfcSpfStream* stream;
+		IfcFile* file;
+		Tokens(IfcSpfStream* s, IfcFile* f);
 		Token Next();
 		~Tokens();
 		std::string TokenString(unsigned int offset);
@@ -136,7 +139,7 @@ namespace IfcParse {
 		
 	public: 
 		Token token;
-		TokenArgument(Token t);
+		TokenArgument(const Token& t);
 		operator int() const;
 		operator bool() const;
 		operator double() const;
@@ -160,7 +163,7 @@ namespace IfcParse {
 	private:		
 		IfcUtil::IfcArgumentSelect* entity;		
 	public:
-		EntityArgument(Ifc2x3::Type::Enum ty, Token t);
+		EntityArgument(Ifc2x3::Type::Enum ty, const Token& t);
 		~EntityArgument();
 		operator int() const;
 		operator bool() const;
@@ -183,15 +186,16 @@ namespace IfcParse {
 	/// ============================
 	class Entity : public IfcAbstractEntity {
 	private:
+		//IfcFile* file;
 		ArgumentPtr args;
 		Ifc2x3::Type::Enum _type;
 	public:
-		/// The EXPRESS ENTITY_NAME
+		/// The EXPRESS ENTITY_INSTANCE_NAME
 		unsigned int _id;
 		/// The offset at which the entity is read
 		unsigned int offset;		
-		Entity(unsigned int i, Tokens* t);
-		Entity(unsigned int i, Tokens* t, unsigned int o);
+		Entity(unsigned int i, IfcFile* t);
+		Entity(unsigned int i, IfcFile* t, unsigned int o);
 		~Entity();
 		IfcEntities getInverse(Ifc2x3::Type::Enum c = Ifc2x3::Type::ALL);
 		IfcEntities getInverse(Ifc2x3::Type::Enum c, int i, const std::string& a);
@@ -204,10 +208,9 @@ namespace IfcParse {
 		bool is(Ifc2x3::Type::Enum v) const;
 		unsigned int id();
 	};
-}
 
 typedef IfcUtil::IfcSchemaEntity IfcEntity;
-typedef IfcEntities IfcEntities;
+//typedef IfcEntities IfcEntities;
 typedef std::map<Ifc2x3::Type::Enum,IfcEntities> MapEntitiesByType;
 typedef std::map<unsigned int,IfcEntity> MapEntityById;
 typedef std::map<std::string,Ifc2x3::IfcRoot::ptr> MapEntityByGuid;
@@ -216,65 +219,56 @@ typedef std::map<unsigned int,unsigned int> MapOffsetById;
 
 /// This class provides several static convenience functions and variables
 /// and provide access to the entities in an IFC file
-class Ifc {
+class IfcFile {
 private:
-	static MapEntityById byid;
-	static MapEntitiesByType bytype;
-	static MapEntitiesByRef byref;
-	static MapEntityByGuid byguid;
-	static MapOffsetById offsets;
-	static unsigned int lastId;
-	static std::ostream* log1;
-	static std::ostream* log2;
-	static std::stringstream log_stream;
+	MapEntityById byid;
+	MapEntitiesByType bytype;
+	MapEntitiesByRef byref;
+	MapEntityByGuid byguid;
+	MapOffsetById offsets;
+	unsigned int lastId;
+	unsigned int MaxId;
 public:
-	/// Returns the first entity in the file, this probably is the entity with the lowest id (EXPRESS ENTITY_NAME)
-	static MapEntityById::const_iterator First();
-	/// Returns the last entity in the file, this probably is the entity with the highes id (EXPRESS ENTITY_NAME)
-	static MapEntityById::const_iterator Last();
-	/// Determines to what stream respectively progress and errors are logged
-	static void SetOutput(std::ostream* l1, std::ostream* l2);
-	/// Log a message to the output stream
-	static void LogMessage(const std::string& type, const std::string& message, const IfcAbstractEntityPtr entity=0);
-	static IfcParse::File* file;
-	static IfcParse::Tokens* tokens;
+	typedef MapEntityById::const_iterator const_iterator;
+	IfcFile();
+	~IfcFile();
+	/// Returns the first entity in the file, this probably is the entity with the lowest id (EXPRESS ENTITY_INSTANCE_NAME)
+	const_iterator begin() const;
+	/// Returns the last entity in the file, this probably is the entity with the highes id (EXPRESS ENTITY_INSTANCE_NAME)
+	const_iterator end() const;
+	IfcParse::IfcSpfStream* file;
+	IfcParse::Tokens* tokens;
 	/// Returns all entities in the file that match the template argument.
 	/// NOTE: This also returns subtypes of the requested type, for example:
 	/// IfcWall will also return IfcWallStandardCase entities
 	template <class T>
-	static typename T::list EntitiesByType() {
+	typename T::list EntitiesByType() {
 		IfcEntities e = EntitiesByType(T::Class());
 		typename T::list l ( new IfcTemplatedEntityList<T>() );
 		if ( e && e->Size() )
-		for ( IfcEntityList::it it = e->begin(); it != e->end(); ++ it ) {
-			l->push(reinterpret_pointer_cast<IfcUtil::IfcBaseClass,T>(*it));
-		}
+            for ( IfcEntityList::it it = e->begin(); it != e->end(); ++ it ) {
+                l->push(reinterpret_pointer_cast<IfcUtil::IfcBaseClass,T>(*it));
+            }
 		return l;
 	}
 	/// Returns all entities in the file that match the positional argument.
 	/// NOTE: This also returns subtypes of the requested type, for example:
 	/// IfcWall will also return IfcWallStandardCase entities
-	static IfcEntities EntitiesByType(Ifc2x3::Type::Enum t);
+	IfcEntities EntitiesByType(Ifc2x3::Type::Enum t);
 	/// Returns all entities in the file that reference the id
-	static IfcEntities EntitiesByReference(int id);
+	IfcEntities EntitiesByReference(int id);
 	/// Returns the entity with the specified id
-	static IfcEntity EntityById(int id);
+	IfcEntity EntityById(int id);
 	/// Returns the entity with the specified GlobalId
-	static Ifc2x3::IfcRoot::ptr EntityByGuid(const std::string& guid);
-	static bool Init(const std::string& fn);
-	static bool Init(std::istream& fn, int len);
-	static bool Init(void* data, int len);
-	static bool Init(IfcParse::File* f);
-	static std::string GetLog();
-	static void Dispose();
-	static bool hasPlaneAngleUnit;
-	static bool SewShells;
-	static double LengthUnit;
-	static double PlaneAngleUnit;
-	static int CircleSegments;
-	static int Verbosity;
+	Ifc2x3::IfcRoot::ptr EntityByGuid(const std::string& guid);
+	bool Init(const std::string& fn);
+	bool Init(std::istream& fn, int len);
+	bool Init(void* data, int len);
+	bool Init(IfcParse::IfcSpfStream* f);
 };
 
 double UnitPrefixToValue( Ifc2x3::IfcSIPrefix::IfcSIPrefix v );
 
+}
+
 #endif
diff --git a/src/ifcparse/IfcUtil.cpp b/src/ifcparse/IfcUtil.cpp
index bf14440b37..6493e4f1d3 100644
--- a/src/ifcparse/IfcUtil.cpp
+++ b/src/ifcparse/IfcUtil.cpp
@@ -62,3 +62,35 @@ IfcUtil::IfcArgumentSelect::IfcArgumentSelect(Ifc2x3::Type::Enum t, ArgumentPtr
 ArgumentPtr IfcUtil::IfcArgumentSelect::wrappedValue() { return arg; }
 bool IfcUtil::IfcArgumentSelect::isSimpleType() { return true; }
 IfcUtil::IfcArgumentSelect::~IfcArgumentSelect() { delete arg; }
+
+void Logger::SetOutput(std::ostream* l1, std::ostream* l2) { 
+	log1 = l1; 
+	log2 = l2; 
+	if ( ! log2 ) {
+		log2 = &log_stream;
+	}
+}
+void Logger::Message(Logger::Severity type, const std::string& message, const IfcAbstractEntityPtr entity) {
+	if ( log2 && type >= verbosity ) {
+		(*log2) << "[" << severity_strings[type] << "] " << message << std::endl;
+		if ( entity ) (*log2) << entity->toString() << std::endl;
+	}
+}
+void Logger::Status(const std::string& message, bool new_line) {
+	if ( log1 ) {
+		(*log1) << message;
+		if ( new_line ) (*log1) << std::endl;
+		else (*log1) << std::flush;
+	}
+}
+std::string Logger::GetLog() {
+	return log_stream.str();
+}
+void Logger::Verbosity(Logger::Severity v) { verbosity = v; }
+Logger::Severity Logger::Verbosity() { return verbosity; }
+
+std::ostream* Logger::log1 = 0;
+std::ostream* Logger::log2 = 0;
+std::stringstream Logger::log_stream;
+Logger::Severity Logger::verbosity = Logger::LOG_NOTICE;
+char* Logger::severity_strings[] = { "Notice","Warning","Error" };
\ No newline at end of file
diff --git a/src/ifcparse/IfcUtil.h b/src/ifcparse/IfcUtil.h
index 408b901034..b5214805cb 100644
--- a/src/ifcparse/IfcUtil.h
+++ b/src/ifcparse/IfcUtil.h
@@ -22,6 +22,7 @@
 
 #include <string>
 #include <vector>
+#include <sstream>
 
 #include "../ifcparse/SharedPointer.h"
 #include "../ifcparse/Ifc2x3enum.h"
@@ -132,9 +133,14 @@ namespace IfcUtil {
 	};
 }
 
+namespace IfcParse {
+	class IfcFile;
+}
+
 class Argument {
-protected:
 public:
+	//void* file;
+//public:
 	virtual operator int() const = 0;
 	virtual operator bool() const = 0;
 	virtual operator double() const = 0;
@@ -154,6 +160,7 @@ public:
 
 class IfcAbstractEntity {
 public:
+	IfcParse::IfcFile* file;
 	virtual IfcEntities getInverse(Ifc2x3::Type::Enum c = Ifc2x3::Type::ALL) = 0;
 	virtual IfcEntities getInverse(Ifc2x3::Type::Enum c, int i, const std::string& a) = 0;
 	virtual std::string datatype() = 0;
@@ -166,4 +173,25 @@ public:
 	virtual unsigned int id() = 0;
 };
 
+class Logger {
+public:
+	typedef enum { LOG_NOTICE, LOG_WARNING, LOG_ERROR } Severity;
+private:
+	static std::ostream* log1;
+	static std::ostream* log2;
+	static std::stringstream log_stream;
+	static Severity verbosity;
+	static char* severity_strings[];
+public:
+	/// Determines to what stream respectively progress and errors are logged
+	static void SetOutput(std::ostream* l1, std::ostream* l2);
+	/// Determines the types of log messages to get logged
+	static void Verbosity(Severity v);
+	static Severity Verbosity();
+	/// Log a message to the output stream
+	static void Message(Severity type, const std::string& message, const IfcAbstractEntityPtr entity=0);
+	static void Status(const std::string& message, bool new_line=true);
+	static std::string Logger::GetLog();
+};
+
 #endif
diff --git a/src/ifcwrap/Interface.h b/src/ifcwrap/Interface.h
index f75512371a..aa13f393d6 100644
--- a/src/ifcwrap/Interface.h
+++ b/src/ifcwrap/Interface.h
@@ -24,6 +24,8 @@ namespace IfcGeomObjects {
 	const int CONVERT_BACK_UNITS = 3;
 	const int USE_BREP_DATA = 4;
 	const int SEW_SHELLS = 5;
+	const int FASTER_BOOLEANS = 6;
+	const int FORCE_CCW_FACE_ORIENTATION = 7;
 
 	class IfcMesh {
 	public: