diff --git a/03-DESIGN/01-to-be/47-delivery-from-commit-to-delivered.md b/03-DESIGN/01-to-be/47-delivery-from-commit-to-delivered.md
index 31a60823..b697e72e 100644
--- a/03-DESIGN/01-to-be/47-delivery-from-commit-to-delivered.md
+++ b/03-DESIGN/01-to-be/47-delivery-from-commit-to-delivered.md
@@ -4,6 +4,7 @@ status: in-progress
 code: [mesh-controller, mesh-catalog modules/mesh-delivery]
 updated: 2026-10-13
 decisions:
+  - "ADR 0350"
   - "ADR 0323"
   - "ADR 0313"
   - "ADR 0306"
@@ -57,7 +58,12 @@ commit's journey and in what order the steps are allowed.
   group, the state table and their state, and nothing else.
 - **The forge's holder** sets a commit's statuses, keeps the delivery's view as one comment on the pull
   request, and appends to the commit's note under `refs/notes/mesh-plan`.
-- **The build seat** builds and checks, asked by the controller as before.
+- **The build seat** builds and checks, asked by the controller as before. **A change is built once** (ADR 0350):
+  a check that passes also builds what its merge would move into the artifact store's scratch namespace, under a
+  reuse key (the source fingerprint and the builder's version), and the walk of the merge commit copies a build
+  of the same key, which the check's verdict names, by digest instead of building. Otherwise the walk builds and
+  says why, per module, in its record. Check builds go when the walk answering the merge ends, when the pull
+  request closes unmerged, and after seven days.
 
 ## A delivery