diff --git a/source/LibRender2/BaseRenderer.cs b/source/LibRender2/BaseRenderer.cs
index 1055f9da7..8f9a404c7 100644
--- a/source/LibRender2/BaseRenderer.cs
+++ b/source/LibRender2/BaseRenderer.cs
@@ -170,7 +170,59 @@ public Vector2 ScaleFactor
 		public bool OptionLighting = true;
 
 		/// <summary>Whether normals rendering is enabled in the debug options</summary>
-		public bool OptionNormals = false;
+		private bool optionNormals = false;
+
+		/// <summary>Whether normals rendering is enabled in the debug options</summary>
+		/// <remarks>Disposing the normals VAO when disabled frees the duplicate vertex buffer held in RAM.</remarks>
+		public bool OptionNormals
+		{
+			get => optionNormals;
+			set
+			{
+				if (value == optionNormals)
+				{
+					return;
+				}
+
+				optionNormals = value;
+				if (!value)
+				{
+					DisposeNormalsVAOs();
+					// Force the GC so the freed normals buffers are gone from RAM immediately.
+					GC.Collect();
+					GC.WaitForPendingFinalizers();
+				}
+			}
+		}
+
+		private void DisposeNormalsVAOs()
+		{
+			if (StaticObjectStates != null)
+			{
+				foreach (var state in StaticObjectStates)
+				{
+					DisposeNormalsVAO(state);
+				}
+			}
+
+			if (DynamicObjectStates != null)
+			{
+				foreach (var state in DynamicObjectStates)
+				{
+					DisposeNormalsVAO(state);
+				}
+			}
+		}
+
+		private static void DisposeNormalsVAO(ObjectState state)
+		{
+			if (state?.Prototype?.Mesh?.NormalsVAO is VertexArrayObject normalsVao)
+			{
+				normalsVao.UnBind();
+				normalsVao.Dispose();
+				state.Prototype.Mesh.NormalsVAO = null;
+			}
+		}
 
 		/// <summary>Whether back face culling is enabled</summary>
 		public bool OptionBackFaceCulling = true;
@@ -1429,10 +1481,28 @@ public void RenderFace(Shader shader, ObjectState state, MeshFace face, bool deb
 				shader.DisableTexturing();
 				shader.SetBrightness(1.0f);
 				shader.SetOpacity(1.0f);
-				VertexArrayObject normalsVao = (VertexArrayObject)state.Prototype.Mesh.NormalsVAO;
-				normalsVao.Bind();
-				lastVAO = normalsVao.handle;
-				normalsVao.Draw(PrimitiveType.Lines, face.NormalsIboStartIndex, face.Vertices.Length * 2);
+				Mesh normalsMesh = state.Prototype.Mesh;
+				if (normalsMesh.NormalsVAO == null)
+				{
+					// Build the normals VAO lazily on first use to avoid holding a duplicate vertex buffer in RAM
+					VAOExtensions.CreateNormalsVAO(normalsMesh, state.Prototype.Dynamic, DefaultShader.VertexLayout, this);
+				}
+				VertexArrayObject normalsVao = (VertexArrayObject)normalsMesh.NormalsVAO;
+				if (normalsVao != null && face.IboStartIndex == 0)
+				{
+					// Draw all normals for this mesh in a single call (the normals VAO is a contiguous list of line pairs).
+					// Solid purple overlay: disable lighting and force a white, emissive material so the shader
+					// outputs the baked per-vertex purple colour unchanged (finalColor *= oLightResult == white).
+					shader.SetIsLight(false);
+					shader.SetMaterialAmbient(Color32.White);
+					shader.SetMaterialFlags(MaterialFlags.Emissive);
+					normalsVao.Bind();
+					lastVAO = normalsVao.handle;
+					normalsVao.DrawArrays(PrimitiveType.Lines, 0, normalsMesh.Vertices.Length > 0 ? normalsMesh.Faces.Sum(f => f.Vertices.Length) * 2 : 0);
+					shader.SetIsLight(OptionLighting);
+					shader.SetMaterialFlags(material.Flags);
+					shader.SetMaterialAmbient(material.Color);
+				}
 			}
 
 			// finalize
diff --git a/source/LibRender2/openGL/Vertex.cs b/source/LibRender2/openGL/Vertex.cs
index fc25cf67c..82f791897 100644
--- a/source/LibRender2/openGL/Vertex.cs
+++ b/source/LibRender2/openGL/Vertex.cs
@@ -39,6 +39,16 @@ public LibRenderVertex(Vector3f position)
 			MatrixChain = new Vector3i(-1, 0, 0);
 		}
 
+		/// <summary>Creates a LibRenderVertex from a position, normal and a solid color (used by the debug normals overlay)</summary>
+		public LibRenderVertex(Vector3 position, Vector3 normal, Color128 color)
+		{
+			Position = new Vector3f(position.X, position.Y, position.Z);
+			Normal = new Vector3f(normal.X, normal.Y, normal.Z);
+			UV = Vector2f.Null;
+			Color = color;
+			MatrixChain = new Vector3i(-1, 0, 0);
+		}
+
 		/// <summary>Creates a LibRenderVertex from a template vertex and a normal</summary>
 		public LibRenderVertex(VertexTemplate template, Vector3f normal)
 		{
diff --git a/source/LibRender2/openGL/VertexArrayObject.cs b/source/LibRender2/openGL/VertexArrayObject.cs
index 6d20cbae3..879537952 100644
--- a/source/LibRender2/openGL/VertexArrayObject.cs
+++ b/source/LibRender2/openGL/VertexArrayObject.cs
@@ -118,6 +118,20 @@ public void Draw(PrimitiveType DrawMode, int Start, int Count)
 			ibo.Draw(DrawMode, Start, Count);
 		}
 
+		/// <summary>
+		/// Draws the VAO using non-indexed rendering (no IBO required).</summary>
+		/// <param name="DrawMode">Specifies the primitive or primitives that will be created from vertices.</param>
+		/// <param name="Start">Start position of the first vertex.</param>
+		/// <param name="Count">Number of vertices to render.</param>
+		/// <remarks>
+		/// Used by the debug normals overlay, where the vertex buffer is already laid out as contiguous line pairs.
+		/// Avoids holding a duplicate index buffer in RAM.
+		/// </remarks>
+		public void DrawArrays(PrimitiveType DrawMode, int Start, int Count)
+		{
+			GL.DrawArrays(DrawMode, Start, Count);
+		}
+
 		/// <summary>
 		/// Unbinds the VAO deactivating the VAO from use
 		/// </summary>
@@ -201,72 +215,163 @@ private static void createVAO(Mesh mesh, bool isDynamic, VertexLayout vertexLayo
 				 *      This marginally helps loading very large objects (as default C# list starts at a capacity of 4 then doubles exponentially)     
 				 */
 
-				var vertexData = new List<LibRenderVertex>(mesh.Vertices.Length);
-				var indexData = new List<uint>();
+			int totalFaceVertices = 0;
+			for (int i = 0; i < mesh.Faces.Length; i++)
+			{
+				totalFaceVertices += mesh.Faces[i].Vertices.Length;
+			}
+
+			var vertexData = new List<LibRenderVertex>(totalFaceVertices);
+			var indexData = new List<uint>(totalFaceVertices);
 
-				var normalsVertexData = new List<LibRenderVertex>(mesh.Vertices.Length * 2);
-				var normalsIndexData = new List<uint>();
+			for (int i = 0; i < mesh.Faces.Length; i++)
+			{
+				mesh.Faces[i].IboStartIndex = indexData.Count;
 
-				for (int i = 0; i < mesh.Faces.Length; i++)
+				foreach (var vertex in mesh.Faces[i].Vertices)
 				{
-					mesh.Faces[i].IboStartIndex = indexData.Count;
-					mesh.Faces[i].NormalsIboStartIndex = normalsIndexData.Count;
+					vertexData.Add(new LibRenderVertex(mesh.Vertices[vertex.Index], vertex.Normal));
+				}
 
-					foreach (var vertex in mesh.Faces[i].Vertices)
-					{
-						vertexData.Add(new LibRenderVertex(mesh.Vertices[vertex.Index], vertex.Normal));
-						normalsVertexData.Add(new LibRenderVertex(mesh.Vertices[vertex.Index].Coordinates));
-						normalsVertexData.Add(new LibRenderVertex(mesh.Vertices[vertex.Index].Coordinates + vertex.Normal));
-					}
+				indexData.AddRange(Enumerable.Range(mesh.Faces[i].IboStartIndex, mesh.Faces[i].Vertices.Length).Select(x => (uint)x));
+			}
 
-					indexData.AddRange(Enumerable.Range(mesh.Faces[i].IboStartIndex, mesh.Faces[i].Vertices.Length).Select(x => (uint)x));
-					normalsIndexData.AddRange(Enumerable.Range(mesh.Faces[i].NormalsIboStartIndex, mesh.Faces[i].Vertices.Length * 2).Select(x => (uint)x));
-				}
+			VertexArrayObject VAO = (VertexArrayObject)mesh.VAO;
+			VAO?.UnBind();
+			VAO?.Dispose();
 
-				VertexArrayObject VAO = (VertexArrayObject)mesh.VAO;
-				VAO?.UnBind();
-				VAO?.Dispose();
+			VAO = new VertexArrayObject();
+			VAO.Bind();
+			VAO.SetVBO(new VertexBufferObject(vertexData.ToArray(), hint));
+			if (indexData.Count > 65530)
+			{
+				//Marginal headroom, although it probably doesn't matter
+				VAO.SetIBO(new IndexBufferObjectUI(indexData.ToArray(), hint));
+			}
+			else
+			{
+				VAO.SetIBO(new IndexBufferObjectUS(indexData.Select(x => (ushort)x).ToArray(), hint));
+			}
 
-				VAO = new VertexArrayObject();
-				VAO.Bind();
-				VAO.SetVBO(new VertexBufferObject(vertexData.ToArray(), hint));
-				if (indexData.Count > 65530)
-				{
-					//Marginal headroom, although it probably doesn't matter
-					VAO.SetIBO(new IndexBufferObjectUI(indexData.ToArray(), hint));
-				}
-				else
+			VAO.SetAttributes(vertexLayout);
+			VAO.UnBind();
+			mesh.VAO = VAO;
+
+			/*
+			 * The normals VAO is only used for the debug normals overlay (OptionNormals).
+			 * It is built lazily via CreateNormalsVAO to avoid holding a second large
+			 * vertex buffer in RAM for every loaded mesh.
+			 */
+			VertexArrayObject NormalsVAO = (VertexArrayObject)mesh.NormalsVAO;
+			NormalsVAO?.UnBind();
+			NormalsVAO?.Dispose();
+			mesh.NormalsVAO = null;
+			}
+			catch (Exception e)
+			{
+				renderer.currentHost.AddMessage(MessageType.Error, false, $"Creating VAO failed with the following error: {e}");
+			}
+		}
+
+		/// <summary>Creates the OpenGL/OpenTK VAO for the normals overlay of a mesh.</summary>
+		/// <remarks>This is built lazily on first use of the normals debug view, as it duplicates the vertex data.</remarks>
+		public static void CreateNormalsVAO(Mesh mesh, bool isDynamic, VertexLayout vertexLayout, BaseRenderer renderer)
+		{
+			if (mesh == null || mesh.NormalsVAO is VertexArrayObject)
+			{
+				return;
+			}
+			if (!renderer.GameWindow.Context.IsCurrent)
+			{
+				renderer.RunInRenderThread(() =>
 				{
-					VAO.SetIBO(new IndexBufferObjectUS(indexData.Select(x => (ushort)x).ToArray(), hint));
-				}
+					createNormalsVAO(mesh, isDynamic, vertexLayout, renderer);
+				}, 2000);
+			}
+			else
+			{
+				createNormalsVAO(mesh, isDynamic, vertexLayout, renderer);
+			}
+		}
 
-				VAO.SetAttributes(vertexLayout);
-				VAO.UnBind();
-				mesh.VAO = VAO;
-				VertexArrayObject NormalsVAO = (VertexArrayObject)mesh.NormalsVAO;
-				NormalsVAO?.UnBind();
-				NormalsVAO?.Dispose();
-
-				NormalsVAO = new VertexArrayObject();
-				NormalsVAO.Bind();
-				NormalsVAO.SetVBO(new VertexBufferObject(normalsVertexData.ToArray(), hint));
-				if (normalsIndexData.Count > 65530)
+		private static void createNormalsVAO(Mesh mesh, bool isDynamic, VertexLayout vertexLayout, BaseRenderer renderer)
+		{
+			if (mesh == null)
+			{
+				return;
+			}
+			try
+			{
+				var hint = isDynamic ? BufferUsageHint.DynamicDraw : BufferUsageHint.StaticDraw;
+
+			int totalFaceVertices = 0;
+			for (int i = 0; i < mesh.Faces.Length; i++)
+			{
+				totalFaceVertices += mesh.Faces[i].Vertices.Length;
+			}
+
+			// Debug normals overlay: a contiguous list of line pairs (vertex -> vertex + normal).
+			// Rendered with DrawArrays (no IBO), so we do not hold a duplicate index buffer in RAM.
+			// Colour is baked per-vertex (purple) because the shader multiplies the uniform colour by the
+			// (zeroed) vertex colour attribute when colour is disabled, which would otherwise render black.
+			var normalsVertexData = new List<LibRenderVertex>(totalFaceVertices * 2);
+			var normalColor = new Color128(0.6f, 0.2f, 1.0f, 1.0f); // purple
+
+			// Scale normal lines relative to the mesh bounding box so they stay a sensible on-screen size.
+			// A fixed 1-unit length blows up into huge overdraw when the camera is close to a small mesh.
+			double scale = 0.01;
+			if (mesh.Vertices.Length > 0)
+			{
+				Vector3 min = mesh.Vertices[0].Coordinates;
+				Vector3 max = mesh.Vertices[0].Coordinates;
+				for (int v = 1; v < mesh.Vertices.Length; v++)
 				{
-					//Marginal headroom, although it probably doesn't matter
-					NormalsVAO.SetIBO(new IndexBufferObjectUI(normalsIndexData.ToArray(), hint));
+					Vector3 c = mesh.Vertices[v].Coordinates;
+					min.X = Math.Min(min.X, c.X); min.Y = Math.Min(min.Y, c.Y); min.Z = Math.Min(min.Z, c.Z);
+					max.X = Math.Max(max.X, c.X); max.Y = Math.Max(max.Y, c.Y); max.Z = Math.Max(max.Z, c.Z);
 				}
-				else
+				double size = Math.Max(max.X - min.X, Math.Max(max.Y - min.Y, max.Z - min.Z));
+				if (size > 0.0)
 				{
-					NormalsVAO.SetIBO(new IndexBufferObjectUS(normalsIndexData.Select(x => (ushort)x).ToArray(), hint));
+					scale = size * 0.01;
 				}
+			}
 
-				NormalsVAO.SetAttributes(vertexLayout);
-				NormalsVAO.UnBind();
-				mesh.NormalsVAO = NormalsVAO;
+			for (int i = 0; i < mesh.Faces.Length; i++)
+			{
+				foreach (var vertex in mesh.Faces[i].Vertices)
+				{
+					Vector3 coordinates = mesh.Vertices[vertex.Index].Coordinates;
+					Vector3 tip = coordinates + vertex.Normal * scale;
+					// Pass the normal so the shader's lighting produces a visible (non-black) colour.
+					// UV/MatrixChain are omitted so the shader cannot sample any texture.
+					normalsVertexData.Add(new LibRenderVertex(coordinates, vertex.Normal, normalColor));
+					normalsVertexData.Add(new LibRenderVertex(tip, vertex.Normal, normalColor));
+				}
 			}
+
+			VertexArrayObject NormalsVAO = (VertexArrayObject)mesh.NormalsVAO;
+			NormalsVAO?.UnBind();
+			NormalsVAO?.Dispose();
+
+			NormalsVAO = new VertexArrayObject();
+			NormalsVAO.Bind();
+			NormalsVAO.SetVBO(new VertexBufferObject(normalsVertexData.ToArray(), hint));
+			// Position + Normal + Colour: UV/matrix omitted so the shader cannot sample any texture,
+			// but the normal is supplied so lighting yields a visible (non-black) colour.
+			var normalsLayout = new VertexLayout
+			{
+				Position = vertexLayout.Position,
+				Normal = vertexLayout.Normal,
+				Color = vertexLayout.Color
+			};
+			NormalsVAO.SetAttributes(normalsLayout);
+			NormalsVAO.UnBind();
+			mesh.NormalsVAO = NormalsVAO;
+		}
 			catch (Exception e)
 			{
-				renderer.currentHost.AddMessage(MessageType.Error, false, $"Creating VAO failed with the following error: {e}");
+				renderer.currentHost.AddMessage(MessageType.Error, false, $"Creating normals VAO failed with the following error: {e}");
 			}
 		}