diff --git a/hurricane/building/portfolio/Hazus v5.1 coupled/pelicun_config.py b/hurricane/building/portfolio/Hazus v5.1 coupled/pelicun_config.py
index 9ad5553c..7ec5e93c 100644
--- a/hurricane/building/portfolio/Hazus v5.1 coupled/pelicun_config.py	
+++ b/hurricane/building/portfolio/Hazus v5.1 coupled/pelicun_config.py	
@@ -288,7 +288,7 @@ def auto_populate(aim):
 
     # make sure missing data is properly represented as null in the JSON
     for key, item in gi.items():
-        if pd.isna(item):
+        if pd.isna(item) or item=="":
             gi[key] = None
 
     # load the schema assuming it is called "input_schema.json" and it is
diff --git a/seismic/building/portfolio/Hazus v6.1/pelicun_config.py b/seismic/building/portfolio/Hazus v6.1/pelicun_config.py
index 3f071f46..39f99613 100644
--- a/seismic/building/portfolio/Hazus v6.1/pelicun_config.py	
+++ b/seismic/building/portfolio/Hazus v6.1/pelicun_config.py	
@@ -74,7 +74,7 @@ def auto_populate(aim):
 
     # make sure missing data is properly represented as null in the JSON
     for key, item in gi.items():
-        if pd.isna(item):
+        if pd.isna(item) or item == "":
             gi[key] = None
 
     # add configuration data to the gi if it is not already there