diff --git a/src/newgrf_airport.cpp b/src/newgrf_airport.cpp
index d526f6d541..2ece7cf0f1 100644
--- a/src/newgrf_airport.cpp
+++ b/src/newgrf_airport.cpp
@@ -31,6 +31,12 @@ template <typename Tspec, typename Tid, Tid Tmax>
 	AirportClass::Get(AirportClass::Allocate('HELI'))->name = STR_AIRPORT_CLASS_HELIPORTS;
 }
 
+template <typename Tspec, typename Tid, Tid Tmax>
+bool NewGRFClass<Tspec, Tid, Tmax>::IsUIAvailable(uint index) const
+{
+	return true;
+}
+
 INSTANTIATE_NEWGRF_CLASS_METHODS(AirportClass, AirportSpec, AirportClassID, APC_MAX)
 
 
diff --git a/src/newgrf_class.h b/src/newgrf_class.h
index 0690c6a514..2dfeceba34 100644
--- a/src/newgrf_class.h
+++ b/src/newgrf_class.h
@@ -21,6 +21,7 @@ template <typename Tspec, typename Tid, Tid Tmax>
 struct NewGRFClass {
 private:
 	uint count;       ///< Number of specs in this class.
+	uint ui_count;    ///< Number of specs in this class potentially available to the user.
 	Tspec **spec;     ///< Array of specifications.
 
 	/**
@@ -43,13 +44,19 @@ public:
 
 	/** Get the number of allocated specs within the class. */
 	uint GetSpecCount() const { return this->count; }
+	/** Get the number of potentially user-available specs within the class. */
+	uint GetUISpecCount() const { return this->ui_count; }
 
 	const Tspec *GetSpec(uint index) const;
 
+	/** Check whether the spec will be available to the user at some point in time. */
+	bool IsUIAvailable(uint index) const;
+
 	static void Reset();
 	static Tid Allocate(uint32 global_id);
 	static void Assign(Tspec *spec);
 	static uint GetClassCount();
+	static uint GetUIClassCount();
 	static NewGRFClass *Get(Tid cls_id);
 
 	static const Tspec *GetByGrf(uint32 grfid, byte local_id, int *index);
diff --git a/src/newgrf_class_func.h b/src/newgrf_class_func.h
index 9bcb6b3c9e..b5af35fdbe 100644
--- a/src/newgrf_class_func.h
+++ b/src/newgrf_class_func.h
@@ -31,6 +31,7 @@ DEFINE_NEWGRF_CLASS_METHOD(void)::ResetClass()
 	this->global_id = 0;
 	this->name      = STR_EMPTY;
 	this->count     = 0;
+	this->ui_count  = 0;
 
 	free(this->spec);
 	this->spec = NULL;
@@ -80,6 +81,8 @@ DEFINE_NEWGRF_CLASS_METHOD(void)::Insert(Tspec *spec)
 	this->spec = ReallocT(this->spec, this->count);
 
 	this->spec[i] = spec;
+
+	if (this->IsUIAvailable(i)) this->ui_count++;
 }
 
 /**
@@ -116,6 +119,19 @@ DEFINE_NEWGRF_CLASS_METHOD(uint)::GetClassCount()
 	return i;
 }
 
+/**
+ * Get the number of classes available to the user.
+ * @return The number of classes.
+ */
+DEFINE_NEWGRF_CLASS_METHOD(uint)::GetUIClassCount()
+{
+	uint cnt = 0;
+	for (uint i = 0; i < Tmax && classes[i].global_id != 0; i++) {
+		if (classes[i].GetUISpecCount() > 0) cnt++;
+	}
+	return cnt;
+}
+
 /**
  * Get a spec from the class at a given index.
  * @param index  The index where to find the spec.
@@ -163,5 +179,6 @@ DEFINE_NEWGRF_CLASS_METHOD(const Tspec *)::GetByGrf(uint32 grfid, byte local_id,
 	template void name::Assign(Tspec *spec); \
 	template NewGRFClass<Tspec, Tid, Tmax> *name::Get(Tid cls_id); \
 	template uint name::GetClassCount(); \
+	template uint name::GetUIClassCount(); \
 	template const Tspec *name::GetSpec(uint index) const; \
 	template const Tspec *name::GetByGrf(uint32 grfid, byte localidx, int *index);
diff --git a/src/newgrf_object.cpp b/src/newgrf_object.cpp
index 1c92c4293d..e38fa9c9ee 100644
--- a/src/newgrf_object.cpp
+++ b/src/newgrf_object.cpp
@@ -113,6 +113,12 @@ template <typename Tspec, typename Tid, Tid Tmax>
 	ObjectClass::Assign(&_object_specs[OBJECT_TRANSMITTER]);
 }
 
+template <typename Tspec, typename Tid, Tid Tmax>
+bool NewGRFClass<Tspec, Tid, Tmax>::IsUIAvailable(uint index) const
+{
+	return this->GetSpec(index)->IsEverAvailable();
+}
+
 INSTANTIATE_NEWGRF_CLASS_METHODS(ObjectClass, ObjectSpec, ObjectClassID, OBJECT_CLASS_MAX)
 
 
diff --git a/src/newgrf_station.cpp b/src/newgrf_station.cpp
index 38e2507ee9..9aee463072 100644
--- a/src/newgrf_station.cpp
+++ b/src/newgrf_station.cpp
@@ -40,6 +40,12 @@ template <typename Tspec, typename Tid, Tid Tmax>
 	classes[1].Insert(NULL);
 }
 
+template <typename Tspec, typename Tid, Tid Tmax>
+bool NewGRFClass<Tspec, Tid, Tmax>::IsUIAvailable(uint index) const
+{
+	return true;
+}
+
 INSTANTIATE_NEWGRF_CLASS_METHODS(StationClass, StationSpec, StationClassID, STAT_CLASS_MAX)
 
 static const uint MAX_SPECLIST = 255;