diff --git a/modules/juce_blocks_basics/blocks/juce_Block.h b/modules/juce_blocks_basics/blocks/juce_Block.h
index 4bc0c3cb2e..8c7eccece5 100644
--- a/modules/juce_blocks_basics/blocks/juce_Block.h
+++ b/modules/juce_blocks_basics/blocks/juce_Block.h
@@ -264,9 +264,12 @@ public:
     virtual void removeProgramEventListener (ProgramEventListener*);
 
     //==============================================================================
-    /** Returns the size of the data block that setDataByte and other functions can write to. */
+    /** Returns the overall memory of the block. */
     virtual uint32 getMemorySize() = 0;
 
+    /** Returns the size of the data block that setDataByte and other functions can write to. */
+    virtual uint32 getHeapMemorySize() = 0;
+
     /** Sets a single byte on the littlefoot heap. */
     virtual void setDataByte (size_t offset, uint8 value) = 0;
 
diff --git a/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp b/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp
index ef65e5f0ed..900ab64a57 100644
--- a/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp
+++ b/modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp
@@ -1741,6 +1741,12 @@ struct PhysicalTopologySource::Internal
             return modelData.programAndHeapSize;
         }
 
+        uint32 getHeapMemorySize() override
+        {
+            jassert (isPositiveAndNotGreaterThan (programSize, modelData.programAndHeapSize));
+            return modelData.programAndHeapSize - programSize;
+        }
+
         void setDataByte (size_t offset, uint8 value) override
         {
             remoteHeap.setByte (programSize + offset, value);