diff --git a/include/openmc/cell.h b/include/openmc/cell.h
index fa5134b60..191458689 100644
--- a/include/openmc/cell.h
+++ b/include/openmc/cell.h
@@ -111,7 +111,10 @@ public:
 
   explicit Cell(pugi::xml_node cell_node);
 
-  //! \brief Determine if a cell contains the particle at a given location.
+  explicit Cell();
+  
+  //! \brief Determine if a cell contains the particle at a given location.  
+  //! Determine if a cell contains the particle at a given location.
   //!
   //! The bounds of the cell are detemined by a logical expression involving
   //! surface half-spaces. At initialization, the expression was converted
@@ -146,5 +149,11 @@ protected:
   bool contains_complex(Position r, Direction u, int32_t on_surface) const;
 };
 
+ class CADCell : public Cell
+{
+  explicit CADCell();
+  
+};
+ 
 } // namespace openmc
 #endif // OPENMC_CELL_H
diff --git a/src/cell.cpp b/src/cell.cpp
index e579b9db4..05bfdb9e9 100644
--- a/src/cell.cpp
+++ b/src/cell.cpp
@@ -209,6 +209,8 @@ Universe::to_hdf5(hid_t universes_group) const
 // Cell implementation
 //==============================================================================
 
+Cell::Cell() {} // empty constructor
+  
 Cell::Cell(pugi::xml_node cell_node)
 {
   if (check_for_node(cell_node, "id")) {
@@ -586,9 +588,13 @@ Cell::contains_complex(Position r, Direction u, int32_t on_surface) const
 }
 
 //==============================================================================
-// Non-method functions
+// CAD Cell implementation
 //==============================================================================
 
+CADCell::CADCell() : Cell{} {};
+  
+//==============================================================================
+// Non-method functions
 extern "C" void
 read_cells(pugi::xml_node* node)
 {
diff --git a/src/surface.cpp b/src/surface.cpp
index 6f34f1f14..5a9c15d10 100644
--- a/src/surface.cpp
+++ b/src/surface.cpp
@@ -138,7 +138,7 @@ void read_coeffs(pugi::xml_node surf_node, int surf_id, double &c1, double &c2,
 // Surface implementation
 //==============================================================================
 
-Surface::Surface() {}
+Surface::Surface() {} // empty constructor
   
 Surface::Surface(pugi::xml_node surf_node)
 {