diff --git a/libsrc/core/.clang-tidy b/libsrc/core/.clang-tidy
index 290188fb..806e0616 100644
--- a/libsrc/core/.clang-tidy
+++ b/libsrc/core/.clang-tidy
@@ -1,4 +1,4 @@
-Checks: '*,-clang-analyzer-alpha.*,-*braces-around-statements,-fuchsia-*,-google-runtime-references,-readability-implicit-bool-conversion,-google-explicit-constructor,-hicpp-explicit-conversions,-google-runtime-int,-llvm-header-guard'
+Checks: '*,-clang-analyzer-alpha.*,-*braces-around-statements,-fuchsia-*,-google-runtime-references,-readability-implicit-bool-conversion,-google-explicit-constructor,-hicpp-explicit-conversions,-google-runtime-int,-llvm-header-guard,-modernize-pass-by-value'
 CheckOptions:
         - key: cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor
           value: 1
diff --git a/libsrc/core/CMakeLists.txt b/libsrc/core/CMakeLists.txt
index 16cec927..8f6cb5ad 100644
--- a/libsrc/core/CMakeLists.txt
+++ b/libsrc/core/CMakeLists.txt
@@ -26,6 +26,7 @@ if(USE_PYTHON)
 endif(USE_PYTHON)
 
 install(FILES ngcore.hpp archive.hpp type_traits.hpp version.hpp ngcore_api.hpp logging.hpp
+  exception.hpp
   DESTINATION ${NG_INSTALL_DIR_INCLUDE}/core COMPONENT netgen_devel)
 
 if(ENABLE_CPP_CORE_GUIDELINES_CHECK)
diff --git a/libsrc/core/archive.hpp b/libsrc/core/archive.hpp
index 05766a14..30c1023c 100644
--- a/libsrc/core/archive.hpp
+++ b/libsrc/core/archive.hpp
@@ -7,13 +7,13 @@
 #include <functional>           // for function
 #include <map>                  // for map
 #include <memory>               // for shared_ptr
-#include <stdexcept>            // for runtime_error
 #include <string>               // for string
 #include <type_traits>          // for declval, enable_if, false_type, is_co...
 #include <typeinfo>             // for type_info
 #include <utility>              // for move, swap, pair
 #include <vector>               // for vector
 
+#include "exception.hpp"        // for UnreachableCodeException, Exception
 #include "logging.hpp"          // for logger
 #include "ngcore_api.hpp"       // for NGCORE_API, unlikely
 #include "type_traits.hpp"      // for all_of_tmpl
@@ -37,7 +37,7 @@ namespace ngcore
     // create new pointer of type T if it is default constructible, else throw
     template<typename T, typename ...Rest>
     T* constructIfPossible_impl(Rest... /*unused*/)
-    { throw std::runtime_error(std::string(Demangle(typeid(T).name())) + " is not default constructible!"); }
+    { throw Exception(std::string(Demangle(typeid(T).name())) + " is not default constructible!"); }
 
     template<typename T, typename= typename std::enable_if<std::is_constructible<T>::value>::type>
     T* constructIfPossible_impl(int /*unused*/) { return new T; } // NOLINT
@@ -140,9 +140,9 @@ namespace ngcore
 
 #ifdef NETGEN_PYTHON
     virtual void ShallowOutPython(const pybind11::object& /*unused*/)
-    { throw std::runtime_error("Should not get in ShallowToPython base class implementation!"); }
+    { throw UnreachableCodeException{}; }
     virtual pybind11::object ShallowInPython()
-    { throw std::runtime_error("Should not get in ShallowFromPython base class implementation!"); }
+    { throw UnreachableCodeException{}; }
 #endif // NETGEN_PYTHON
 
     Archive& operator=(const Archive&) = delete;
@@ -284,9 +284,9 @@ namespace ngcore
               NETGEN_DEBUG_LOG(logger, "Typids are different: " + Demangle(typeid(T).name()) + " vs. " +
                                Demangle(typeid(*ptr).name()));
               if(!IsRegistered(Demangle(typeid(*ptr).name())))
-                  throw std::runtime_error(std::string("Archive error: Polymorphic type ")
-                                           + Demangle(typeid(*ptr).name())
-                                           + " not registered for archive");
+                  throw Exception(std::string("Archive error: Polymorphic type ")
+                                  + Demangle(typeid(*ptr).name())
+                                  + " not registered for archive");
               reg_ptr = GetArchiveRegister(Demangle(typeid(*ptr).name())).downcaster(typeid(T), ptr.get());
               // if there was a true downcast we have to store more information
               if(reg_ptr != static_cast<void*>(ptr.get()))
@@ -404,9 +404,9 @@ namespace ngcore
               NETGEN_DEBUG_LOG(logger, "Typeids are different: " + Demangle(typeid(T).name()) + " vs. " +
                                Demangle(typeid(*p).name()));
               if(!IsRegistered(Demangle(typeid(*p).name())))
-                throw std::runtime_error(std::string("Archive error: Polymorphic type ")
-                                         + Demangle(typeid(*p).name())
-                                         + " not registered for archive");
+                throw Exception(std::string("Archive error: Polymorphic type ")
+                                + Demangle(typeid(*p).name())
+                                + " not registered for archive");
               reg_ptr = GetArchiveRegister(Demangle(typeid(*p).name())).downcaster(typeid(T), static_cast<void*>(p));
               if(reg_ptr != static_cast<void*>(p))
                 {
@@ -427,8 +427,8 @@ namespace ngcore
                                  return (*this) << -1 & (*p);
                                }
                 else
-                  throw std::runtime_error(std::string("Archive error: Class ") +
-                                           Demangle(typeid(*p).name()) + " does not provide a default constructor!");
+                  throw Exception(std::string("Archive error: Class ") +
+                                  Demangle(typeid(*p).name()) + " does not provide a default constructor!");
               else
                 {
                   // if a pointer to a base class is archived, the class hierarchy must be registered
@@ -436,9 +436,9 @@ namespace ngcore
                   // implement a void DoArchive(Archive&) member function
                   // To recreate the object we need to store the true type of it
                   if(!IsRegistered(Demangle(typeid(*p).name())))
-                    throw std::runtime_error(std::string("Archive error: Polymorphic type ")
-                                             + Demangle(typeid(*p).name())
-                                             + " not registered for archive");
+                    throw Exception(std::string("Archive error: Polymorphic type ")
+                                    + Demangle(typeid(*p).name())
+                                    + " not registered for archive");
                   NETGEN_DEBUG_LOG(logger, "Store a possibly more complicated pointer");
                   return (*this) << -3 << Demangle(typeid(*p).name()) & (*p);
                 }
@@ -552,11 +552,11 @@ namespace ngcore
     {
       static void* tryUpcast (const std::type_info& /*unused*/, T* /*unused*/)
       {
-        throw std::runtime_error("Upcast not successful, some classes are not registered properly for archiving!");
+        throw Exception("Upcast not successful, some classes are not registered properly for archiving!");
       }
       static void* tryDowncast (const std::type_info& /*unused*/, void* /*unused*/)
       {
-        throw std::runtime_error("Downcast not successful, some classes are not registered properly for archiving!");
+        throw Exception("Downcast not successful, some classes are not registered properly for archiving!");
       }
     };
 
@@ -568,7 +568,7 @@ namespace ngcore
         try
           { return GetArchiveRegister(Demangle(typeid(B1).name())).
               upcaster(ti, static_cast<void*>(dynamic_cast<B1*>(p))); }
-        catch(std::exception&)
+        catch(const Exception&)
           { return Caster<T, Brest...>::tryUpcast(ti, p); }
       }
 
@@ -581,7 +581,7 @@ namespace ngcore
             return dynamic_cast<T*>(static_cast<B1*>(GetArchiveRegister(Demangle(typeid(B1).name())).
                                                      downcaster(ti, p)));
           }
-        catch(std::exception&)
+        catch(const Exception&)
           {
             return Caster<T, Brest...>::tryDowncast(ti, p);
           }
diff --git a/libsrc/core/exception.hpp b/libsrc/core/exception.hpp
new file mode 100644
index 00000000..248a180f
--- /dev/null
+++ b/libsrc/core/exception.hpp
@@ -0,0 +1,68 @@
+#ifndef NETGEN_CORE_EXCEPTION_HPP
+#define NETGEN_CORE_EXCEPTION_HPP
+
+#include <sstream>         // for stringstream
+#include <stdexcept>       // for exception
+#include <string>          // for string
+
+#include "ngcore_api.hpp"  // for NGCORE_API
+
+namespace ngcore
+{
+  // Exception for code that shouldn't be executed
+  class NGCORE_API UnreachableCodeException : public std::exception
+  {
+    const char* what() const noexcept override
+    {
+      return "Shouldn't get here, something went wrong!";
+    }
+  };
+
+  // Default exception class
+  class NGCORE_API Exception : public std::exception
+  {
+    /// a verbal description of the exception
+    std::string m_what;
+  public:
+    Exception() = default;
+    Exception(const Exception&) = default;
+    Exception(Exception&&) = default;
+    Exception(const std::string& s) : m_what(s) {}
+    Exception(const char* s) : m_what(s) {}
+    ~Exception() override = default;
+
+    Exception& operator =(const Exception&) = default;
+    Exception& operator =(Exception&&) noexcept = default;
+
+    /// append string to description
+    Exception & Append (const std::string & s) { m_what += s; return *this; }
+  /// append string to description
+    Exception & Append (const char * s) { m_what += s; return *this; }
+
+    /// verbal description of exception
+    const std::string & What() const { return m_what; }
+
+    /// implement virtual function of std::exception
+    const char* what() const noexcept override { return m_what.c_str(); }
+  };
+
+  // Out of Range exception
+  class NGCORE_API RangeException : public Exception
+  {
+  public:
+    /// where it occurs, index, minimal and maximal indices
+    RangeException (const std::string & where, 
+                    int ind, int imin, int imax) : Exception("")
+      {
+        std::stringstream str;
+        str << where << ": index " << ind << " out of range [" << imin << "," << imax << "]\n";
+        Append (str.str());
+      }
+  };
+
+  // Exception used if no simd implementation is available to fall back to standard evaluation
+  class NGCORE_API ExceptionNOSIMD : public Exception
+  { public: using Exception::Exception; };
+} // namespace ngcore
+
+#endif // NETGEN_CORE_EXCEPTION_HPP
diff --git a/libsrc/core/ngcore.hpp b/libsrc/core/ngcore.hpp
index ea7f8eab..b345a114 100644
--- a/libsrc/core/ngcore.hpp
+++ b/libsrc/core/ngcore.hpp
@@ -2,6 +2,7 @@
 #define NETGEN_CORE_NGCORE_HPP
 
 #include "archive.hpp"
+#include "exception.hpp"
 #include "logging.hpp"
 #include "version.hpp"