diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69f482f..79e6b66 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Change Log
 
+## [0.3.10]
+
+    -  BREAKING: changed signatures of create_variant function and route
+
 ## [0.3.9]
 
     -  BREAKING: inserting multiple networks with the same name does not represent an error anymore, networks are only unique by their net_id (_id field of the collection)
diff --git a/pandahub/api/routers/variants.py b/pandahub/api/routers/variants.py
index 22e92ca..9526798 100644
--- a/pandahub/api/routers/variants.py
+++ b/pandahub/api/routers/variants.py
@@ -30,13 +30,23 @@ def get_variants(data: GetVariantsModel, ph=Depends(pandahub)):
 
 class CreateVariantModel(BaseModel):
     project_id: str
-    variant_data: dict
+    net_id: int
+    name: str | None = None
+    default_name: str | None = None
+
+
+class CreateVariantResponseModel(BaseModel):
+    net_id: int
+    index: int
+    name: str | None = None
+    date_created: int
+    date_changed: int
+
 
 @router.post("/create_variant")
-def create_variant(data: CreateVariantModel, ph=Depends(pandahub)):
-    project_id = data.project_id
-    ph.set_active_project_by_id(project_id)
-    return ph.create_variant(data.variant_data)
+def create_variant(data: CreateVariantModel, ph=Depends(pandahub)) -> CreateVariantResponseModel:
+    ph.set_active_project_by_id(data.project_id)
+    return ph.create_variant(net_id=data.net_id, name=data.name, default_name=data.default_name)
 
 class DeleteVariantModel(BaseModel):
     project_id: str
diff --git a/pandahub/lib/PandaHub.py b/pandahub/lib/PandaHub.py
index 6a0a505..15fd7cb 100644
--- a/pandahub/lib/PandaHub.py
+++ b/pandahub/lib/PandaHub.py
@@ -2,6 +2,7 @@
 import builtins
 import json
 import logging
+import time
 import warnings
 from inspect import signature, _empty
 from collections.abc import Callable
@@ -91,6 +92,7 @@ def __init__(
         user_id=None,
         datatypes=DATATYPES,
         mongodb_indexes=MONGODB_INDEXES,
+        elements_without_vars = None,
     ):
         mongo_client_args = {
             "host": connection_url,
@@ -115,6 +117,7 @@ def __init__(
                 {"var_type": np.nan},
             ]
         }
+        self._elements_without_vars = ["variant"] if elements_without_vars is None else elements_without_vars
         if check_server_available:
             self.server_is_available()
 
@@ -1150,10 +1153,13 @@ def write_network_to_db(
                 if element_data.empty:
                     continue
                 element_data = element_data.copy(deep=True)
-                if "var_type" in element_data:
-                    element_data["var_type"] = element_data["var_type"].fillna("base")
-                else:
-                    element_data["var_type"] = "base"
+                if element not in self._elements_without_vars:
+                    if "var_type" in element_data:
+                        element_data["var_type"] = element_data["var_type"].fillna("base")
+                    else:
+                        element_data["var_type"] = "base"
+                        element_data["not_in_var"] = np.empty((len(element_data.index), 0)).tolist()
+                        element_data["variant"] = None
                 element_data = convert_element_to_dict(element_data, net_id, self._datatypes.get(element))
                 self._write_element_to_db(db, element, element_data)
 
@@ -1228,9 +1234,12 @@ def _get_net_id_from_name(self, name, db):
     def _network_with_name_exists(self, name, db):
         return self._get_net_id_from_name(name, db) is not None
 
+    def _get_net_collections(self, db, with_areas=True):
+        return self.get_net_collections(db, with_areas)
+
     def get_net_collections(self, db=None, with_areas=True):
         if db is None:
-            db = self._get_project_database()
+            db = self.get_project_database()
         if with_areas:
             collection_filter = {"name": {"$regex": "^net_"}}
         else:
@@ -1402,7 +1411,7 @@ def delete_elements(
         """
         if not isinstance(element_indexes, list):
             raise TypeError("Parameter element_indexes must be a list of ints!")
-        validate_variant_type(variant)
+        self.validate_variant(variant, element_type)
         if project_id:
             self.set_active_project_by_id(project_id)
 
@@ -1446,7 +1455,7 @@ def set_net_value_in_db(
         project_id=None,
         **kwargs,
     ):
-        validate_variant_type(variant)
+        self.validate_variant(variant, element_type)
         if project_id:
             self.set_active_project_by_id(project_id)
         self.check_permission("write")
@@ -1514,7 +1523,7 @@ def set_object_attribute(
         variant=None,
         project_id=None,
     ):
-        validate_variant_type(variant)
+        self.validate_variant(variant, element_type)
         if project_id:
             self.set_active_project_by_id(project_id)
         self.check_permission("write")
@@ -1636,7 +1645,7 @@ def create_elements(
         list
             A list of the created elements (elements_data with added _id fields)
         """
-        validate_variant_type(variant)
+        self.validate_variant(variant, element_type)
         if project_id:
             self.set_active_project_by_id(project_id)
         self.check_permission("write")
@@ -1771,24 +1780,30 @@ def _get_int_index(self, collection: str, index_field: str = "_id", query_filter
     # Variants
     # -------------------------
 
-    def create_variant(self, data, index: Optional[int] = None):
+    def create_variant(
+        self,
+        net_id: int,
+        name: str | None = None,
+        default_name: str = "Variant",
+        index: int | None = None,
+    ) -> dict:
         db = self._get_project_database()
-        net_id = int(data["net_id"])
         if index is None:
             index = self._get_int_index("variant", index_field="index", query_filter={"net_id": net_id})
-        data["index"] = index
-        if data.get("default_name") is not None and data.get("name") is None:
-            data["name"] = data.pop("default_name") + " " + str(index)
-        db["variant"].insert_one(data)
-        del data["_id"]
-
-        if index == 1:
-            for coll in self.get_net_collections(db):
-                db[coll].update_many(
-                    {"$or": [{"var_type": None}, {"var_type": np.nan}]},
-                    {"$set": {"var_type": "base", "not_in_var": [], "variant": None}},
-                )
-        return data
+
+        if name is None:
+            name = f"{default_name}  {index + 1}"
+        now = int(time.time())
+        variant = {
+            "net_id": net_id,
+            "index": index,
+            "name": name,
+            "date_created": now,
+            "date_changed": now,
+        }
+        db["variant"].insert_one(variant)
+        del variant["_id"]
+        return variant
 
     def delete_variant(self, net_id, index):
         db = self._get_project_database()
@@ -1828,12 +1843,17 @@ def get_variant_filter(self, variant: int | None) -> dict:
         dict
             mongodb query filter for the given variant
         """
-        validate_variant_type(variant)
+        self.validate_variant(variant)
         if variant is None:
             return self.base_variant_filter
         return {"$or": [{"var_type": "base", "not_in_var": {"$ne": variant}},
                         {"var_type": {"$in": ["change", "addition"]}, "variant": variant}, ]}
 
+    def validate_variant(self, variant: int | None, element_type: str | None = None):
+        """Raise a ValueError if variant is not int | None or element_type does not support variants."""
+        validate_variant_type(variant)
+        if element_type is not None and variant is not None and element_type in self._elements_without_vars:
+            raise ValueError(f"{element_type} does not support variants")
 
     # -------------------------
     # Bulk operations
diff --git a/pyproject.toml b/pyproject.toml
index 0b81e1f..6ca7d12 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "pandahub"
-version = "0.3.9"  # File format version '__format_version__' is tracked in __init__.py
+version = "0.3.10"  # File format version '__format_version__' is tracked in __init__.py
 authors=[
     { name = "Jan Ulffers", email = "jan.ulffers@iee.fraunhofer.de" },
     { name = "Leon Thurner", email = "leon.thurner@retoflow.de" },