diff --git a/all2vec/__init__.py b/all2vec/__init__.py
index 00bf739..28019a7 100644
--- a/all2vec/__init__.py
+++ b/all2vec/__init__.py
@@ -232,7 +232,7 @@ def get_similar_threshold(self, entity_type, entity_id, match_type,
     def get_entity_types(self):
         """Helper for getting entity types object."""
         return [{
-            'num_entities': etype._ann_obj.get_n_items(),
+            'num_entities': etype._nitems,
             'entity_type_id': etype._entity_type_id,
             'entity_type': etype._entity_type,
             'metric':  etype._metric,
@@ -263,6 +263,53 @@ def save(self, folder):
         files.append(info_file)
         return files
 
+    def build_and_save(self, folder, verbose=False):
+        """Preserve memory by deleting index after build and save."""
+        if self._is_built:
+            return
+
+        if not os.path.exists(folder):
+            os.makedirs(folder)
+        files = []
+
+        for annoy_object in self._annoy_objects.values():
+            logging.info("Starting build for entity {} - {}...".format(
+                annoy_object._entity_type_id,
+                annoy_object._entity_type,
+            ))
+            annoy_object.build(verbose)
+            logging.info("Done build for entity {} - {}".format(
+                annoy_object._entity_type_id,
+                annoy_object._entity_type,
+            ))
+            annoy_filepath = os.path.join(folder, "{}.ann".format(
+                annoy_object._entity_type,
+            ))
+            annoy_object._ann_obj.save(annoy_filepath)
+            files.append(annoy_filepath)
+            logging.info("Done saving for entity {} - {}".format(
+                annoy_object._entity_type_id,
+                annoy_object._entity_type,
+            ))
+
+            # Release memory
+            del annoy_object._ann_obj
+
+        self._is_built = True
+
+        pickle_filepath = os.path.join(folder, 'object.pickle')
+        with open(pickle_filepath, 'wb') as handle:
+            dill.dump(self, handle)
+        files.append(pickle_filepath)
+
+        enttypes = self.get_entity_types()
+
+        info_file = os.path.join(folder, 'entity_info.json')
+        with open(info_file, 'w') as handle:
+            json.dump(enttypes, handle)
+        files.append(info_file)
+        return files
+
     def load_entities(self, entities, file_getter):
         """Load underlying entities."""
         for k in entities: