diff --git a/hub/persistence/models/city_object.py b/hub/persistence/models/city_object.py
index c3b4ae90..a93101ec 100644
--- a/hub/persistence/models/city_object.py
+++ b/hub/persistence/models/city_object.py
@@ -9,6 +9,7 @@ import datetime
 import logging
 
 from sqlalchemy import Column, Integer, String, Sequence, ForeignKey, Float
+from sqlalchemy.dialects.postgresql import JSON
 from sqlalchemy import DateTime
 
 from hub.city_model_structure.building import Building
@@ -27,7 +28,7 @@ class CityObject(Models):
   type = Column(String, nullable=False)
   year_of_construction = Column(Integer, nullable=True)
   function = Column(String, nullable=True)
-  usage = Column(String, nullable=True)
+  usage = Column(JSON, nullable=True)
   volume = Column(Float, nullable=False)
   area = Column(Float, nullable=False)
   total_heating_area = Column(Float, nullable=False)