diff --git a/src/ifcgeom/IfcGeomObjects.cpp b/src/ifcgeom/IfcGeomObjects.cpp
index 5878d1c509..dd6627f316 100644
--- a/src/ifcgeom/IfcGeomObjects.cpp
+++ b/src/ifcgeom/IfcGeomObjects.cpp
@@ -598,28 +598,36 @@ double UnitPrefixToValue( IfcSchema::IfcSIPrefix::IfcSIPrefix v ) {
 }
 
 void IfcGeomObjects::InitPrecision() {
-	IfcSchema::IfcGeometricRepresentationContext::list rep_contexts = ifc_file->EntitiesByType<IfcSchema::IfcGeometricRepresentationContext>();
-	// Currently, IfcGeometricRepresentationContext aren't used as much as they should be
-	// in the evaluation of shape representations, hence, we try to find the one with the
-	// lowest precision. Typically, a value of 1e-5 is encountered. This value is applied
-	// to all TopoDS_Shapes generated by one of the IfcGeom::convert() functions.
-	// TODO: Many of the empirically found tolerances should probably be substituted by
-	// one that is defined in the model file.
-	double lowest_precision_encountered = std::numeric_limits<double>::infinity();
-	bool any_precision_encountered = false;
-	for (IfcSchema::IfcGeometricRepresentationContext::it it = rep_contexts->begin(); it != rep_contexts->end(); ++it) {
-		IfcSchema::IfcGeometricRepresentationContext* rep_context = *it;
-		if (rep_context->is(IfcSchema::Type::IfcGeometricRepresentationSubContext)) continue;
-		if (rep_context->hasPrecision()) {
-			const double precision = rep_context->Precision();
-			if (precision < lowest_precision_encountered) {
-				any_precision_encountered = true;
-				lowest_precision_encountered = precision;
+	IfcGeom::SetValue(IfcGeom::GV_PRECISION, 0.00001);
+
+	try {
+		IfcSchema::IfcGeometricRepresentationContext::list rep_contexts = ifc_file->EntitiesByType<IfcSchema::IfcGeometricRepresentationContext>();
+		// Currently, IfcGeometricRepresentationContext aren't used as much as they should be
+		// in the evaluation of shape representations, hence, we try to find the one with the
+		// lowest precision. Typically, a value of 1e-5 is encountered. This value is applied
+		// to all TopoDS_Shapes generated by one of the IfcGeom::convert() functions.
+		// TODO: Many of the empirically found tolerances should probably be substituted by
+		// one that is defined in the model file.
+		double lowest_precision_encountered = std::numeric_limits<double>::infinity();
+		bool any_precision_encountered = false;
+		for (IfcSchema::IfcGeometricRepresentationContext::it it = rep_contexts->begin(); it != rep_contexts->end(); ++it) {
+			IfcSchema::IfcGeometricRepresentationContext* rep_context = *it;
+			if (rep_context->is(IfcSchema::Type::IfcGeometricRepresentationSubContext)) continue;
+			if (rep_context->hasPrecision()) {
+				const double precision = rep_context->Precision();
+				if (precision < lowest_precision_encountered) {
+					any_precision_encountered = true;
+					lowest_precision_encountered = precision;
+				}
 			}
 		}
-	}
-	if (any_precision_encountered) {
-		IfcGeom::SetValue(IfcGeom::GV_PRECISION, lowest_precision_encountered);
+		if (any_precision_encountered) {
+			IfcGeom::SetValue(IfcGeom::GV_PRECISION, lowest_precision_encountered);
+		}
+	} catch (const IfcParse::IfcException& ex) {
+		std::stringstream ss;
+		ss << "Failed to determine precision value '" << ex.what() << "'";
+		Logger::Message(Logger::LOG_ERROR, ss.str());
 	}
 }
 
@@ -633,23 +641,32 @@ void IfcGeomObjects::InitUnits() {
 	
 	IfcSchema::IfcUnitAssignment::list unit_assignments = ifc_file->EntitiesByType<IfcSchema::IfcUnitAssignment>();
 	IfcUtil::IfcAbstractSelect::list units = IfcUtil::IfcAbstractSelect::list();
-	if ( unit_assignments->Size() ) {
-		IfcSchema::IfcUnitAssignment::ptr unit_assignment = *unit_assignments->begin();
-		units = unit_assignment->Units();
-	}
-	if ( ! units ) {
+	try {
+		if ( unit_assignments->Size() ) {
+			IfcSchema::IfcUnitAssignment::ptr unit_assignment = *unit_assignments->begin();
+			units = unit_assignment->Units();
+		}
+	} catch (const IfcParse::IfcException&) {}
+
+	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.
 		IfcSchema::IfcExtrudedAreaSolid::list extrusions = ifc_file->EntitiesByType<IfcSchema::IfcExtrudedAreaSolid>();
 		if ( ! extrusions->Size() ) return;
 		double max_height = -1.0f;
 		for ( IfcSchema::IfcExtrudedAreaSolid::it it = extrusions->begin(); it != extrusions->end(); ++ it ) {
-			const double depth = (*it)->Depth();
-			if ( depth > max_height ) max_height = depth;
+			try {
+				const double depth = (*it)->Depth();
+				if ( depth > max_height ) max_height = depth;
+			} catch (const IfcParse::IfcException&) {}
+		}
+		if ( max_height > 100.0f ) {
+			IfcGeom::SetValue(IfcGeom::GV_LENGTH_UNIT,0.001);
+			Logger::Message(Logger::LOG_NOTICE, "Guessed length unit to be in millimeters based on extrusion 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 ) {
 			std::string current_unit_name = "";
@@ -691,8 +708,10 @@ void IfcGeomObjects::InitUnits() {
 				}
 			}
 		}
-	} catch ( IfcParse::IfcException ex ) {
-		Logger::Message(Logger::LOG_ERROR,ex.what());
+	} catch (const IfcParse::IfcException& ex) {
+		std::stringstream ss;
+		ss << "Failed to determine unit information '" << ex.what() << "'";
+		Logger::Message(Logger::LOG_ERROR, ss.str());
 	}
 }