diff --git a/src/engine/buildingGlyph.ts b/src/engine/buildingGlyph.ts
index 8250575..7f268a1 100644
--- a/src/engine/buildingGlyph.ts
+++ b/src/engine/buildingGlyph.ts
@@ -49,6 +49,18 @@ interface WindowPlacement {
 }
 
 const DEFAULT_BODY = 0x8d9aa4;
+/**
+ * Pane and door thickness, in true metres.
+ *
+ * These were 0.012 and 0.028 **scene units**, chosen against the Bay Area
+ * board (94.3 m to the unit) so a pane stood 1.13 m proud and a door 2.64 m.
+ * On the merged board that is 23 m of glass and a 54 m door — measured on the
+ * HQ glyph at Salesforce Tower while hunting the 700 m FiDi slab. Same class
+ * of bug as the pin, the aeroplane, and the freeway ribbon: a constant in
+ * scene units is a constant that assumes one board.
+ */
+const PANE_DEPTH_M = 1.13;
+const DOOR_DEPTH_M = 2.64;
 const WINDOW_DAY = new THREE.Color(0x334c5d);
 const WINDOW_LIT = new THREE.Color(0xd7c68d);
 
@@ -203,7 +215,7 @@ export function createBuildingGlyph(
   windows.forEach((window, i) => {
     position.set(window.x, window.y, window.z);
     quaternion.setFromAxisAngle(up, window.yaw);
-    scale.set(window.width, window.height, 0.012);
+    scale.set(window.width, window.height, PANE_DEPTH_M * horizontal);
     matrix.compose(position, quaternion, scale);
     windowMesh.setMatrixAt(i, matrix);
     // A few warm panes stop the repeated grid reading as graph paper. The
@@ -248,7 +260,7 @@ export function createBuildingGlyph(
     vertical(first.base),
     (first.z + first.depth / 2 + 0.18) * horizontal,
   );
-  door.scale.set(doorWidth * horizontal, vertical(doorHeight), 0.028);
+  door.scale.set(doorWidth * horizontal, vertical(doorHeight), DOOR_DEPTH_M * horizontal);
   door.castShadow = false;
   group.add(door);
   pickables.push(door);
diff --git a/src/test/buildingGlyph.test.ts b/src/test/buildingGlyph.test.ts
index b7baa88..fd80f3a 100644
--- a/src/test/buildingGlyph.test.ts
+++ b/src/test/buildingGlyph.test.ts
@@ -1,7 +1,12 @@
 import assert from "node:assert/strict";
 import { describe, it } from "node:test";
-import { layoutBuildingGlyph } from "../engine/buildingGlyph.ts";
-import type { BuildingGlyph } from "../engine/types.ts";
+import * as THREE from "three";
+import { createBuildingGlyph, layoutBuildingGlyph } from "../engine/buildingGlyph.ts";
+import type { BuildingGlyph, City } from "../engine/types.ts";
+import { World } from "../engine/world.ts";
+import { setReconcile } from "../cities/reconcile.ts";
+
+setReconcile(false);
 
 function glyph(overrides: Partial<BuildingGlyph> = {}): BuildingGlyph {
   return {
@@ -57,3 +62,72 @@ describe("map building glyph layouts", () => {
     );
   });
 });
+
+/** The same square of ground at two scales; see `markerScale.test.ts`. */
+function board(latScale: number): City {
+  return {
+    id: `glyph-scale-${latScale}`,
+    name: "Glyph Scale Board",
+    center: { lat: 37.78, lng: -122.42 },
+    bounds: { minLat: 37.7, maxLat: 37.86, minLng: -122.5, maxLng: -122.34 },
+    latScale,
+    verticalExaggeration: 3.6,
+    cellLat: 0.01,
+    cellLng: 0.01,
+    coastFalloff: 0.02,
+    landmasses: [
+      [
+        [37.71, -122.49],
+        [37.85, -122.49],
+        [37.85, -122.35],
+        [37.71, -122.35],
+      ],
+    ],
+    parks: [],
+    inlandWater: [],
+    districts: [],
+    landmarks: [],
+    bridges: [],
+    roads: [],
+    chapters: [],
+    hills: [],
+  };
+}
+
+const HQ: BuildingGlyph = {
+  kind: "building",
+  width: 48,
+  depth: 42,
+  height: 326,
+  storeys: 61,
+  heading: 205,
+  profile: "tower",
+  seed: 115,
+  bodyColor: 0x8799a8,
+};
+
+function doorDepthM(latScale: number): number {
+  const world = new World(board(latScale));
+  const built = createBuildingGlyph(world, HQ, 0xf5b53f);
+  let depthM = 0;
+  built.group.traverse((node) => {
+    if (!(node instanceof THREE.Mesh) || node.name !== "building entrance") return;
+    node.updateWorldMatrix(true, false);
+    depthM = Math.abs(node.scale.z) * world.metresPerUnit;
+  });
+  built.dispose();
+  return depthM;
+}
+
+describe("a building glyph is a true-metre object", () => {
+  it("draws the same door thickness on a 94 m board and a 1,919 m one", () => {
+    const metro = doorDepthM(1180);
+    const state = doorDepthM(58);
+    assert.ok(metro > 1 && metro < 6, `a door ${metro.toFixed(2)} m thick is not a door`);
+    assert.ok(
+      Math.abs(metro - state) < 0.05,
+      `a door is ${metro.toFixed(2)} m thick on a 94 m/unit board and ` +
+        `${state.toFixed(2)} m on a 1,919 m/unit one`,
+    );
+  });
+});