diff --git a/src/c3nav/mapdata/render/renderer.py b/src/c3nav/mapdata/render/renderer.py
index 8c62afdf..cd623ef4 100644
--- a/src/c3nav/mapdata/render/renderer.py
+++ b/src/c3nav/mapdata/render/renderer.py
@@ -127,15 +127,16 @@ class LevelRenderer():
                                          fill_opacity=0.06))
 
         if show_accessibles:
-            main_geometry = self.level.geometries.accessible.buffer(-0.6, join_style=MITRE)
-            clear_geometry = self.level.geometries.accessible.buffer(-0.3, join_style=MITRE)
-            missing_geometry = clear_geometry.difference(main_geometry.buffer(0.31, join_style=MITRE))
+            narrowed_geometry = self.level.geometries.accessible.buffer(-0.6, join_style=MITRE)
+            clear_geometry = self.level.geometries.accessible.buffer(-0.3, join_style=JOIN_STYLE.mitre)
+            wide_geometry = narrowed_geometry.buffer(0.31, join_style=MITRE).intersection(clear_geometry)
+            missing_geometry = clear_geometry.difference(wide_geometry.buffer(0.01, join_style=MITRE))
 
             contents.append(self.polygon_svg(clear_geometry,
                                              fill_color='#FFFF00',
                                              fill_opacity=0.5))
 
-            contents.append(self.polygon_svg(main_geometry,
+            contents.append(self.polygon_svg(narrowed_geometry,
                                              fill_color='#009900',
                                              fill_opacity=0.5))
 
diff --git a/src/c3nav/routing/area.py b/src/c3nav/routing/area.py
index 1d5c4b00..a5a60836 100644
--- a/src/c3nav/routing/area.py
+++ b/src/c3nav/routing/area.py
@@ -33,7 +33,7 @@ class GraphArea():
 
                 angle_diff = ((stair_angle - angle + 180) % 360) - 180
                 up = angle_diff < 0  # noqa
-                if not (50 < abs(angle_diff) < 130):
+                if not (40 < abs(angle_diff) < 150):
                     valid = False
                     break
 
diff --git a/src/c3nav/routing/room.py b/src/c3nav/routing/room.py
index a48a1a53..ae99672f 100644
--- a/src/c3nav/routing/room.py
+++ b/src/c3nav/routing/room.py
@@ -53,8 +53,8 @@ class GraphRoom():
             self.areas.append(GraphArea(self, mpl_clear, mpl_stairs))
 
     def build_points(self):
-        original_geometry = self.geometry
-        geometry = original_geometry.buffer(-0.6, join_style=JOIN_STYLE.mitre)
+        narrowed_geometry = self.geometry.buffer(-0.6, join_style=JOIN_STYLE.mitre)
+        geometry = narrowed_geometry.buffer(0.31, join_style=JOIN_STYLE.mitre).intersection(self.clear_geometry)
 
         if geometry.is_empty:
             return