diff --git a/docs/DESIGN.md b/docs/DESIGN.md
index 21c4b28..243b2c7 100644
--- a/docs/DESIGN.md
+++ b/docs/DESIGN.md
@@ -466,6 +466,11 @@ above, including:
   no ribs and no sidewall, that carries at belt speed like a flat one (90 grains/s); only uphill
   runs are sidewall belts. A whole run also shares one cleat phase, so pieces added later line up
   with it.
+- **Build range about the size of the screen (t64, 2026-10-27).** The owner asked whether
+  building needs a range limit at all, since the bot needs no arms to build. Agreed: keep a limit,
+  but make it about what's on screen, so anything the player can see and aim at builds directly
+  and anything beyond stays a blueprint built when the bot comes near. No limit at all would let
+  players build in places they've never been and link far claims instantly. Not built yet.
 
 ## Ideas not built yet