diff --git a/src/ifcconvert/IfcConvert.cpp b/src/ifcconvert/IfcConvert.cpp
index 28e2fefd6d..d4203c2e4a 100644
--- a/src/ifcconvert/IfcConvert.cpp
+++ b/src/ifcconvert/IfcConvert.cpp
@@ -296,7 +296,7 @@ int main(int argc, char** argv)
 			"Applicable for DAE output.")
         ("center-model",
             "Centers the elements upon serialization by applying the center point of "
-            "all placements as an offset. Applicable for OBJ and DAE output.")
+            "all placements as an offset. Applicable for OBJ and DAE output. Can take several minutes on large models.")
         ("model-offset", po::value<std::string>(&offset_str),
             "Applies an arbitrary offset of form 'x;y;z' to all placements. Applicable for OBJ and DAE output.")
 		("site-local-placement",
@@ -638,7 +638,7 @@ int main(int argc, char** argv)
 
 	int old_progress = quiet ? 0 : -1;
 
-    if (center_model || model_offset) {
+    if (is_tesselated && (center_model || model_offset)) {
         double* offset = serializer->settings().offset;
         if (center_model) {
 			if (site_local_placement || building_local_placement) {
@@ -646,6 +646,11 @@ int main(int argc, char** argv)
 				delete serializer;
 				return EXIT_FAILURE;
 			}
+
+            if (!quiet) Logger::Status("Computing bounds...");
+            context_iterator.compute_bounds();
+            if (!quiet) Logger::Status("Done!");
+
             gp_XYZ center = (context_iterator.bounds_min() + context_iterator.bounds_max()) * 0.5;
             offset[0] = -center.X();
             offset[1] = -center.Y();
diff --git a/src/ifcgeom/IfcGeomIterator.h b/src/ifcgeom/IfcGeomIterator.h
index ca80a77f7b..9814304e63 100644
--- a/src/ifcgeom/IfcGeomIterator.h
+++ b/src/ifcgeom/IfcGeomIterator.h
@@ -285,6 +285,13 @@ namespace IfcGeom {
 			done = 0;
 			total = representations->size();
 
+			return true;
+		}
+
+        /// Computes model's bounding box (bounds_min and bounds_max).
+        /// @note Can take several minutes for large files.
+        void compute_bounds()
+        {
             for (int i = 1; i < 4; ++i) {
                 bounds_min_.SetCoord(i, std::numeric_limits<double>::infinity());
                 bounds_max_.SetCoord(i, -std::numeric_limits<double>::infinity());
@@ -294,21 +301,21 @@ namespace IfcGeom {
             for (IfcSchema::IfcProduct::list::it iter = products->begin(); iter != products->end(); ++iter) {
                 IfcSchema::IfcProduct* product = *iter;
                 if (product->hasObjectPlacement()) {
-					// Use a fresh trsf every time in order to prevent the result to be concatenated
+                    // Use a fresh trsf every time in order to prevent the result to be concatenated
                     gp_Trsf trsf; 
-					bool success = false;
-					
-					try {
-						success = kernel.convert(product->ObjectPlacement(), trsf);
-					} catch (const std::exception& e) {
-						Logger::Error(e);
-					} catch (...) {
-						Logger::Error("Failed to construct placement");
-					}
-					
-					if (!success) {
-						continue;
-					}
+                    bool success = false;
+
+                    try {
+                        success = kernel.convert(product->ObjectPlacement(), trsf);
+                    } catch (const std::exception& e) {
+                        Logger::Error(e);
+                    } catch (...) {
+                        Logger::Error("Failed to construct placement");
+                    }
+
+                    if (!success) {
+                        continue;
+                    }
 
                     const gp_XYZ& pos = trsf.TranslationPart();
                     bounds_min_.SetX(std::min(bounds_min_.X(), pos.X()));
@@ -319,9 +326,7 @@ namespace IfcGeom {
                     bounds_max_.SetZ(std::max(bounds_max_.Z(), pos.Z()));
                 }
             }
-
-			return true;
-		}
+        }
 
 		int progress() const { return 100 * done / total; }