diff --git a/.trellis/workspace/dingkang/index.md b/.trellis/workspace/dingkang/index.md
index 3dddb84..eb59ccb 100644
--- a/.trellis/workspace/dingkang/index.md
+++ b/.trellis/workspace/dingkang/index.md
@@ -8,7 +8,7 @@
 
 <!-- @@@auto:current-status -->
 - **Active File**: `journal-1.md`
-- **Total Sessions**: 12
+- **Total Sessions**: 13
 - **Last Active**: 2026-08-03
 <!-- @@@/auto:current-status -->
 
@@ -19,7 +19,7 @@
 <!-- @@@auto:active-documents -->
 | File | Lines | Status |
 |------|-------|--------|
-| `journal-1.md` | ~259 | Active |
+| `journal-1.md` | ~280 | Active |
 <!-- @@@/auto:active-documents -->
 
 ---
@@ -29,6 +29,7 @@
 <!-- @@@auto:session-history -->
 | # | Date | Title | Commits | Branch |
 |---|------|-------|---------|--------|
+| 13 | 2026-08-03 | Fix OSM multipolygon buildings | `95f8458` | `main` |
 | 12 | 2026-08-03 | Optional GLB compression stage | `7ba8594` | `main` |
 | 11 | 2026-08-03 | Adopt Shapespark vegetation | `dbb5705` | `main` |
 | 10 | 2026-08-03 | Reject low-poly scrub bush experiment | `e58a928` | `main` |
diff --git a/.trellis/workspace/dingkang/journal-1.md b/.trellis/workspace/dingkang/journal-1.md
index 305defb..ee74ee5 100644
--- a/.trellis/workspace/dingkang/journal-1.md
+++ b/.trellis/workspace/dingkang/journal-1.md
@@ -257,3 +257,24 @@ Added an explicit compress stage and GLB compression script for nantaizi WebP re
 ### Status
 
 [OK] **Completed**
+
+
+## Session 13: Fix OSM multipolygon buildings
+
+**Date**: 2026-08-03
+**Task**: Fix OSM multipolygon buildings
+**Branch**: `main`
+
+### Summary
+
+Parsed building multipolygon relations, generated building holes, and respected explicit OSM height for nantaizi relation -65.
+
+### Git Commits
+
+| Hash | Message |
+|------|---------|
+| `95f8458` | (see git log) |
+
+### Status
+
+[OK] **Completed**