diff --git a/src/include/Commons.h b/src/include/Commons.h
index b7245d03a2c58eb5f6c3bc459879cfd4d8f4ca2b..bc3775c0d7331e30dacf6e3913a6b7637786f3de 100644
--- a/src/include/Commons.h
+++ b/src/include/Commons.h
@@ -452,6 +452,18 @@ public:
    */
   std::string get_descriptor_type() override { return "cluster descriptor"; }
   
+  /*! \brief Function to calculate the descriptor size in bytes.
+   *
+   * \param gconf: `GeometryConfiguration *` Pointer to a GeometryConfiguration instance.
+   * \param gconf: `ScattererConfiguration *` Pointer to a ScattererConfiguration instance.
+   * \param li: `int` Maximum expansion order for internal fields (optional, default from `gconf`).
+   * \param le: `int` Maximum expansion order for external fields (optional, default from `gconf`).
+   * \return size: `long` The descriptor size in bytes.
+   */
+  static long get_size(
+    GeometryConfiguration *gconf, ScattererConfiguration *sconf, int li=-1, int le=-1
+  ) { return 0; }
+  
   /*! \brief Update the field expansion orders.
    *
    * \param inner_order: `int` The new inner expansion order to be set.
@@ -502,6 +514,18 @@ public:
    */
   std::string get_descriptor_type() override { return "inclusion descriptor"; }
   
+  /*! \brief Function to calculate the descriptor size in bytes.
+   *
+   * \param gconf: `GeometryConfiguration *` Pointer to a GeometryConfiguration instance.
+   * \param gconf: `ScattererConfiguration *` Pointer to a ScattererConfiguration instance.
+   * \param li: `int` Maximum expansion order for internal fields (optional, default from `gconf`).
+   * \param le: `int` Maximum expansion order for external fields (optional, default from `gconf`).
+   * \return size: `long` The descriptor size in bytes.
+   */
+  static long get_size(
+    GeometryConfiguration *gconf, ScattererConfiguration *sconf, int li=-1, int le=-1
+  ) { return 0; }
+  
   /*! \brief Update the field expansion orders.
    *
    * \param inner_order: `int` The new inner expansion order to be set.
@@ -552,6 +576,17 @@ public:
    */
   std::string get_descriptor_type() override { return "sphere descriptor"; }
   
+  /*! \brief Function to calculate the descriptor size in bytes.
+   *
+   * \param gconf: `GeometryConfiguration *` Pointer to a GeometryConfiguration instance.
+   * \param gconf: `ScattererConfiguration *` Pointer to a ScattererConfiguration instance.
+   * \param lm: `int` Maximum field expansion order (optional, default from `gconf`).
+   * \return size: `long` The descriptor size in bytes.
+   */
+  static long get_size(
+    GeometryConfiguration *gconf, ScattererConfiguration *sconf, int lm=-1
+  ) { return 0; }
+  
   /*! \brief Update the field expansion order.
    *
    * \param order: `int` The new field expansion order to be set.