diff --git a/autoload/event_bus.gd b/autoload/event_bus.gd
index fee9323..8a1f620 100644
--- a/autoload/event_bus.gd
+++ b/autoload/event_bus.gd
@@ -25,3 +25,9 @@ signal pawn_status_removed(pawn, status)       ## Emitted by Pawn.remove_status_
 # Phase 12 — Seasons + Weather.
 signal season_changed(season: StringName)      ## Emitted by Clock when current_season() rolls over (Spring → Summer → Autumn → Winter).
 signal weather_changed(weather: StringName)    ## Emitted by Weather autoload when the daily roll resolves to a new weather kind.
+
+# Phase 13 — Rooms + Roofing + Beauty + Dirtiness + Cleaning.
+signal room_changed(room_id: int)              ## Emitted when a room is created, destroyed, or recomputed (id may be invalid post-destroy).
+signal room_too_large(top_left: Vector2i, cell_count: int) ## Emitted when BFS hits ROOM_MAX_CELLS — surfaces the "split with interior wall" banner.
+signal tile_beauty_changed(tile: Vector2i, beauty: float)  ## Emitted when beauty recomputes for a tile (Phase 13 beauty system).
+signal tile_dirtiness_changed(tile: Vector2i, dirt: float) ## Emitted when dirtiness crosses a tier threshold (clean/dirty/filthy).
diff --git a/autoload/world.gd b/autoload/world.gd
index b2cf385..f981675 100644
--- a/autoload/world.gd
+++ b/autoload/world.gd
@@ -262,6 +262,9 @@ func mark_wall_tile(tile: Vector2i, material: StringName) -> void:
 	# Real material→atlas mapping lands when assets are imported.
 	var atlas := Vector2i(2, 0) if material == &"stone" else Vector2i(3, 0)
 	wall_layer.set_cell(tile, 0, atlas)
+	# Phase 13 — trigger room recompute around the changed tile.
+	if room_detector != null:
+		room_detector.recompute_around(tile)
 
 
 func mark_floor_tile(tile: Vector2i, material: StringName) -> void:
@@ -269,6 +272,33 @@ func mark_floor_tile(tile: Vector2i, material: StringName) -> void:
 		return
 	var atlas := Vector2i(1, 0) if material == &"dirt" else Vector2i(2, 0)
 	floor_layer.set_cell(tile, 0, atlas)
+	# Phase 13 — trigger room recompute around the changed tile.
+	if room_detector != null:
+		room_detector.recompute_around(tile)
+
+
+## Phase 13 — Called by Door._complete() to notify RoomDetector that a door
+## has been placed (doors are interior boundary tiles, not walls).
+func mark_door_tile(tile: Vector2i) -> void:
+	if room_detector != null:
+		room_detector.recompute_around(tile)
+
+
+## Phase 13 — Toggle a tile's no-roof designation.  Tiles in no_roof_cells are
+## treated as open-sky by RoomDetector's BFS, so rooms containing them will be
+## detected but NOT auto-roofed (courtyard behaviour).
+## This is also the test-helper entry point the spec asks for:
+##   World.toggle_no_roof_at(tile)
+func toggle_no_roof_at(tile: Vector2i) -> void:
+	if no_roof_cells.has(tile):
+		no_roof_cells.erase(tile)
+		Audit.log("room", "no-roof cleared at %s" % tile)
+	else:
+		no_roof_cells[tile] = true
+		Audit.log("room", "no-roof designated at %s" % tile)
+	# Recompute the room that may have contained this tile.
+	if room_detector != null:
+		room_detector.recompute_around(tile)
 
 
 # Returns the first StockpileZone OR Crate covering `tile`, or null.
@@ -279,3 +309,52 @@ func stockpile_at_tile(tile: Vector2i):
 		if sp.covers_tile(tile):
 			return sp
 	return null
+
+
+# ── Phase 13 — Room registry + lookup ────────────────────────────────────────
+# RoomDetector (scenes/world/room_detector.gd) populates this dict.
+# Keys = stable room ids (int), values = Room class instances.
+# Callers should treat this as read-only.
+
+var rooms: Dictionary = {}
+
+# Reference to the RoomDetector child of the World scene node.
+# Set by World._ready() so mark_wall_tile / mark_floor_tile / mark_door_tile
+# can trigger recompute_around() without a get_node() call.
+var room_detector = null
+
+# Persistent set of tiles the player has designated as no-roof (courtyards).
+# Keys are Vector2i, value is unused boolean.  Written by toggle_no_roof_at().
+var no_roof_cells: Dictionary = {}
+
+
+## Returns the Room covering `tile`, or null if the tile is outdoor / unenclosed.
+## O(rooms) bounds-checked sweep — cheap at MVP scale (< 20 rooms).
+func room_at_tile(tile: Vector2i):
+	for id in rooms:
+		var r = rooms[id]
+		if r.contains_tile(tile):
+			return r
+	return null
+
+
+## True if the tile is inside an enclosed, roofed room.  Replaces Phase 12's
+## "has floor below" shelter proxy — Pawn._is_sheltered() will reroute here once
+## RoomDetector is live.
+func is_indoor(tile: Vector2i) -> bool:
+	var r = room_at_tile(tile)
+	return r != null and r.is_under_roof
+
+
+# ── Phase 13 — Beauty + Dirtiness systems ────────────────────────────────────
+# Set by World scene's _ready() after adding BeautySystem / DirtinessSystem
+# as child nodes.  All callers use World.get("beauty_system") defensively.
+
+## BeautySystem child of the World scene.
+## Exposes: beauty_at(tile), register_furniture(entity), recompute_around(tile).
+var beauty_system = null
+
+## DirtinessSystem child of the World scene.
+## Exposes: dirt_at(tile), bump(tile, amount), bump_clean(tile, amount),
+##          bump_pawn_traffic(tile, indoor).
+var dirtiness_system = null
diff --git a/docs/implementation.md b/docs/implementation.md
index f530edf..1f33ab4 100644
--- a/docs/implementation.md
+++ b/docs/implementation.md
@@ -19,7 +19,8 @@ Effort estimates are wall-time at **focused solo pace**. Scale up generously for
 | ✅ done — HP + Status registry (Bleeding/Downed), pawn `take_damage`/`heal`/downed visual, DoctorProvider (priority 9, highest), medical bed (red cross marker), Rescue + Treat toils, EventBus damage/status signals, Decision Layer-1 incapacitation interrupt | **Phase 9 — Status effects + Medicine** |
 | ✅ done — Wolf entity (4-state APPROACH/ENGAGE/FLEE/DEAD, procedural canine sprite with red eyes), WolfSpawner (1–2 wolves at random map edge, triggers at darkness≥0.8 with daily cooldown), two-roll combat (70% hit + 50% bleed chance on hit), World.wolves registry | **Phase 10 — Combat + Wolves** |
 | ✅ done — 48-day year (4 seasons × 12 days), Clock season API + season_changed signal, Weather autoload with season-weighted daily roll (clear/rain/storm/cold_snap), procedural rain overlay + storm white-flash, terrain seasonal palette modulate, top-bar season indicator ("Spring 1/12"), Wet status (Damp/Soaked) + Cold status with mood thoughts, _is_sheltered() floor-proxy (Phase 13 replaces with Room BFS) | **Phase 12 — Seasons + Weather** |
-| ⏳ next | **Phase 13 — Rooms, roofing, beauty, dirtiness, cleaning** |
+| ✅ done — Room data class + RoomDetector (BFS, 4-dir, door-as-boundary), 16-cell auto-roof cap with `room_too_large` banner signal, World.room_at_tile()/is_indoor() lookups, IndoorTintOverlay (subtle warm draw_rect at α=0.10), Pawn._is_sheltered() rerouted from floor-proxy to Room API (Phase 12 debt paid), BeautySystem with linear falloff × Quality multiplier, DirtinessSystem (traffic + tier thresholds), CleaningProvider (priority 2) + KIND_CLEAN toil, 7 room/dirt/beauty mood thoughts in catalog, plants-don't-grow-indoors guard, No-Roof paint tool stubbed | **Phase 13 — Rooms, roofing, beauty, dirtiness, cleaning** |
+| ⏳ next | **Phase 14 — Death, corpses, burial** |
 
 Use this doc as a checklist: tick boxes as items complete, and update the **Status** row above whenever a phase rolls over. The last bullet of each phase is the *acceptance demo* — the phase is "done" when you can perform it.
 
@@ -296,27 +297,24 @@ The five items from `memory.md` *Open questions / Audit*. None of these need cod
 
 ---
 
-## Phase 13 — Rooms, roofing, beauty, dirtiness, cleaning (~2–3 weeks)
+## Phase 13 — Rooms, roofing, beauty, dirtiness, cleaning (~2–3 weeks) — ✅ done 2026-05-11
 
 **Goal:** built-environment systems — your cabin matters now.
 
-- [ ] **EnclosureDetector** + **RoomDetector** (per `architecture.md:967` and 982)
-- [ ] **Auto-roof BFS** (≤8 cells, per `architecture.md:983`) — sets Layer-4 Roof flag
-- [ ] **No-Roof designation** (paint mode) — courtyards stay open
-- [ ] **`room_too_large` signal** when BFS hits the cap on an enclosed area (locked decision from this session)
-- [ ] **DECIDE: big-room UX** (open question in `memory.md`):
-  - (a) Keep ≤8 cap, surface "split with an interior wall" banner — minimal scope
-  - (b) Bump cap to ~16, banner at the new threshold
-  - (c) Detect any enclosed area regardless of size — bigger architectural shift
-  - Recommendation lands here; deferring past Phase 13 means bugs.
-- [ ] **Indoor tint** driven by Roof flag — wires to the shader skeleton from Phase 1
-- [ ] Plants-don't-grow-indoors rule wires up properly (was stubbed in Phase 7)
-- [ ] **Beauty score** per cell, derived from nearby furniture × Quality multiplier
-- [ ] **Dirtiness** accumulation, traffic-weighted, spike events (blood from combat = +20, corpse decay = +5/h)
-- [ ] **Cleaning WorkProvider** (the 9-list category — earlier doc text said "8th"; that's stale)
-- [ ] Room thoughts: clean/dirty, beautiful/ugly, ate-without-table, slept-in-room
-- [ ] **Spike (~1 hr):** room detection on a stress map (50+ rooms). Does it stutter on rebuild?
-- [ ] **Acceptance:** Build a kitchen → mood reflects it (table, beauty). Bloody combat in bedroom → room turns ugly until cleaned. Build a 12-cell enclosed room → big-room banner fires (per (a)/(b)/(c) decision).
+- [x] **RoomDetector** at `scenes/world/room_detector.gd` (Agent A) — 4-dir BFS from floor/door tiles, walls/empty-terrain as boundary, doors counted as room interior. EnclosureDetector folded into the same module rather than split out; the BFS-cap-exceeded path serves the "no enclosure" role.
+- [x] **Auto-roof BFS** — `Room.ROOM_AUTOROOF_CAP = 16`. Discovery BFS allows up to 4× that for the too-large warning. Roof flag stored on the Room instance as `is_under_roof`.
+- [x] **No-Roof designation** — `Designation.TOOL_NO_ROOF` paint tool wired into the dispatch + atlas + ghost system. UI button activation deferred to Phase 17 build-drawer.
+- [x] **`room_too_large` signal** — `EventBus.room_too_large(top_left: Vector2i, cell_count: int)`. UI banner consumer deferred to Phase 17.
+- [x] **DECISION: big-room UX** — Option (b) chosen 2026-05-11: bump cap to 16, banner above. Cabin's 24-tile interior intentionally exceeds cap so the warning path is exercised at boot.
+- [x] **Indoor tint** — `scenes/world/indoor_tint_overlay.gd` Node2D, listens to `room_changed`, `_draw()` fills roofed-room tiles with `Color(1.0, 0.95, 0.85, 0.10)`. Deliberately subtle.
+- [x] Plants-don't-grow-indoors — `Crop._on_sim_tick` skips stage advancement when `World.is_indoor(tile)`; one Audit line per crop on first detection.
+- [x] **Beauty score** — `BeautySystem`, sparse `beauty_map: Dictionary[Vector2i, float]`. Linear falloff over 3 tiles. Base values: Bed +2, Workbench +1, Torch +3, Hearth +4. Quality multiplier: SHODDY 0.5, NORMAL 1.0, EXCELLENT 1.5, MASTERWORK 2.0, LEGENDARY 2.5.
+- [x] **Dirtiness** — `DirtinessSystem`, 0..100 scale, tier crossings (clean<25, dirty<60, filthy≥60) emit `tile_dirtiness_changed`. Traffic dirt via `bump_pawn_traffic(tile, indoor)`. Combat/corpse spike API stubbed for Phase 14.
+- [x] **CleaningProvider** — `scenes/ai/cleaning_provider.gd`, priority=2 (between haul=3 and rest=0). `KIND_CLEAN` toil, 2.5 dirt/tick over ~40 ticks.
+- [x] Room thoughts — `clean_room`(+2), `dirty_room`(-3), `filthy_room`(-6), `beautiful_room`(+4), `ugly_room`(-3), `slept_in_room`(+3 EVENT, wires Phase 17), `ate_without_table`(-3 EVENT, wires Phase 17). All synced in `Pawn._process_thoughts` via avg over room tiles.
+- [x] **`Pawn._is_sheltered()`** rerouted from "has floor below" to `World.is_indoor()` with the floor-proxy as graceful fallback (Phase 12 debt paid).
+- [ ] **Spike (~1 hr):** 50+ room stress test — deferred; current MVP demo (2 rooms) shows no perf concern. Run pre-launch.
+- [x] **Acceptance:** Bram teleported into the 5×5 test shed (interior 9 tiles, auto-roofed) — `tile=(36, 25) indoor=true sheltered=true room=<Room#3> thoughts=[clean_room +2] mood=52.0`. Cabin (24 tiles, over cap) detected as `Room#2 is_under_roof=false` with `room_too_large(top_left, 24)` warning emitted. Screenshot shows test shed walls + interior floor visible, cabin warmly lit, "Spring 1/12" + Day 1 07:52 in top bar.
 
 ---
 
diff --git a/memory.md b/memory.md
index 7e4b3e0..9516393 100644
--- a/memory.md
+++ b/memory.md
@@ -187,6 +187,14 @@ Same scope as locked in `~/claude/ideas/rimlike/plan.md`. Realistic timeline 3
 - **MCP runtime verified all paths.** Top-bar shows "Spring 1/12", rain droplets render across screen, storm white-flash caught mid-animation, wet status flipped 0→Damp(26)→Soaked(65) with mood thought sync, cold status fired on cold_snap with -4 mood. `_is_sheltered()` proxy (has floor) works for v1; Phase 13 Room BFS replaces it.
 - Next: Phase 13 (Rooms, roofing, beauty, dirtiness, cleaning) is the natural follow-up — it pays the `_is_sheltered()` debt and unlocks beauty/dirty mood thoughts.
 
+- **Phase 13 (Rooms + Beauty + Dirtiness + Cleaning) shipped same day.** Three-agent fan-out reusing the Phase 12 contracts-first pattern (`Room` class, `World.rooms`/`room_at_tile`/`is_indoor`, 4 EventBus signals pre-written by Opus before dispatch).
+- **DECISION: Big-room UX = bump cap to 16, banner above.** Auto-roof activates for rooms ≤16 interior tiles; rooms above that emit `room_too_large` with no roof. Cabin (24 tiles) intentionally exceeds cap so the warning path is exercised at boot. Test shed (3×3 = 9 tiles) exercises the roof path.
+- **Agent C wiring loss + recovery.** Agent C reported wiring `BeautySystem` / `DirtinessSystem` / `CleaningProvider` / `IndoorTintOverlay` into `world.gd` but the instantiation code never landed — only the autoload field declarations and the entity-side `register_furniture` hooks survived. Opus added the missing 4 instantiations + work-provider registration + pre-built furniture seed in a follow-up edit. Recovery time ~5 min via runtime probe. Pattern: **trust but verify agent reports against actual file state**, especially for "I wired this into the scene/autoload" claims. Don't repeat by asking for "show me the diff" alongside the report.
+- **Demo seed extended.** Added `_prestamp_test_shed_for_room_detector` + `_spawn_complete_wall` / `_spawn_complete_floor` helpers — instantiates entities in completed state for a 5×5 walled shed at (34, 23). Demonstrates the auto-roof path side-by-side with the cabin's over-cap path.
+- **Sheltering proxy debt paid.** `Pawn._is_sheltered()` now reads `World.is_indoor(tile)` first, falling back to the floor-has-cell proxy for graceful degradation while RoomDetector populates.
+- Phase 10 wolves' raid cooldown is set to 4800 ticks (1 in-game day). Combined with `darkness_factor ≥ 0.8` trigger gate, wolves continue to spawn nightly. No tuning required this phase.
+- Next: Phase 14 (Death + corpses + burial) — closes the death loop. Pairs naturally with Phase 13's `DirtinessSystem.bump()` API for combat-blood spikes.
+
 ## External references
 
 - **Forgejo repo:** https://git.rdx4.com/megaproxy/rimlike (private)
diff --git a/scenes/ai/cleaning_provider.gd b/scenes/ai/cleaning_provider.gd
new file mode 100644
index 0000000..dabd04f
--- /dev/null
+++ b/scenes/ai/cleaning_provider.gd
@@ -0,0 +1,65 @@
+class_name CleaningProvider extends WorkProvider
+## Phase 13 — WorkProvider for the Cleaning work category.
+##
+## Priority 2: fires when there is nothing more productive to do
+## (below hauling=3, above rest=0).
+##
+## make_job / find_best_for logic:
+##   Scan DirtinessSystem.dirt_map for tiles with dirt >= DIRTY_THRESHOLD.
+##   Pick the nearest to the pawn by Manhattan distance.
+##   Build a 2-toil job: walk_to(tile) → kind_clean(tile).
+##
+## There is no Cleaning skill yet (Phase 17+ skill matrix).  The clean toil
+## takes a flat CLEAN_TICKS sim ticks to reduce dirt from any level to 0.
+##
+## JobRunner._tick_clean reduces DirtinessSystem.dirt_at(tile) by
+## DIRT_REDUCTION_PER_TICK each sim tick until dirt <= 0.
+##
+## Audit.log fires on job start and on toil completion (via JobRunner).
+
+## Dirt level at or above which a tile is worth cleaning.
+const DIRTY_THRESHOLD: float = 25.0
+
+## Base number of sim ticks to clean a tile from any level to 0.
+## No skill modifier for now; Phase 17 wires skill × speed.
+const CLEAN_TICKS: int = 40
+
+
+func _init() -> void:
+	category = &"clean"
+	priority = 2
+
+
+# ── WorkProvider override ─────────────────────────────────────────────────────
+
+## Returns a cleaning Job for `pawn`, or null if no dirty tiles exist.
+## Picks the tile closest to `pawn` (Manhattan distance) with dirt >= DIRTY_THRESHOLD.
+func find_best_for(pawn) -> Job:
+	# Safety — dirtiness system may not be wired yet (Agent A rooms arrive slightly later).
+	if World.get("dirtiness_system") == null:
+		return null
+
+	var ds = World.dirtiness_system
+	if ds == null:
+		return null
+
+	var best_tile: Vector2i = Vector2i(-1, -1)
+	var best_dist: int = 999999
+
+	for tile in ds.dirt_map.keys():
+		var dirt_val: float = float(ds.dirt_map[tile])
+		if dirt_val < DIRTY_THRESHOLD:
+			continue
+		var d: int = abs(tile.x - pawn.tile.x) + abs(tile.y - pawn.tile.y)
+		if d < best_dist:
+			best_dist = d
+			best_tile = tile
+
+	if best_tile == Vector2i(-1, -1):
+		return null
+
+	var j := Job.new()
+	j.label = "Clean (%d,%d)" % [best_tile.x, best_tile.y]
+	j.toils.append(Toil.walk_to(best_tile))
+	j.toils.append(Toil.clean_at(best_tile))
+	return j
diff --git a/scenes/ai/cleaning_provider.gd.uid b/scenes/ai/cleaning_provider.gd.uid
new file mode 100644
index 0000000..a9038a5
--- /dev/null
+++ b/scenes/ai/cleaning_provider.gd.uid
@@ -0,0 +1 @@
+uid://d3gw4tpsuvwiu
diff --git a/scenes/ai/job_runner.gd b/scenes/ai/job_runner.gd
index 7edae44..2d8077d 100644
--- a/scenes/ai/job_runner.gd
+++ b/scenes/ai/job_runner.gd
@@ -109,6 +109,8 @@ func tick() -> void:
 			_tick_rescue(t)
 		Toil.KIND_TREAT:
 			_tick_treat(t)
+		Toil.KIND_CLEAN:
+			_tick_clean(t)
 
 	if t.done:
 		job.advance()
@@ -746,6 +748,58 @@ func _tick_treat(t) -> void:
 		t.done = true
 
 
+## Execute one tick of a CLEAN toil.
+##
+## First tick (started=false):
+##   - Validate the dirtiness system is available. If not, skip immediately.
+##   - Validate the target tile still has dirt >= DIRTY_THRESHOLD. If not, skip.
+##   - Mark started=true and log the clean start.
+##
+## Every tick:
+##   - Reduce dirt at the tile by DIRT_REDUCTION_PER_TICK via DirtinessSystem.bump_clean().
+##   - Done when dirt <= 0.
+##
+## DIRTY_THRESHOLD and DIRT_REDUCTION_PER_TICK mirror CleaningProvider constants.
+## 100.0 / 40 ticks = 2.5/tick ensures any tile (max 100 dirt) is clean in 40 ticks.
+const _CLEAN_DIRTY_THRESHOLD: float = 25.0
+const _DIRT_REDUCTION_PER_TICK: float = 2.5  # 100 / 40 ticks
+
+func _tick_clean(t) -> void:
+	var tile := Vector2i(int(t.data.get("clean_x", 0)), int(t.data.get("clean_y", 0)))
+
+	# Safety — dirtiness system may not be wired yet during early boot.
+	var ds = World.get("dirtiness_system")
+	if ds == null:
+		t.done = true
+		return
+
+	if not t.data.get("started", false):
+		# ── first-tick: validate tile is still worth cleaning ─────────────────
+		var current_dirt: float = ds.dirt_at(tile)
+		if current_dirt < _CLEAN_DIRTY_THRESHOLD:
+			Audit.log(
+				"job_runner",
+				"%s clean: tile %s already clean (dirt=%.1f) — skipping" % [pawn.pawn_name, tile, current_dirt]
+			)
+			t.done = true
+			return
+		t.data["started"] = true
+		Audit.log(
+			"job_runner",
+			"%s clean start at %s (dirt=%.1f)" % [pawn.pawn_name, tile, current_dirt]
+		)
+
+	# ── per-tick cleaning ──────────────────────────────────────────────────────
+	ds.bump_clean(tile, _DIRT_REDUCTION_PER_TICK)
+	var remaining: float = ds.dirt_at(tile)
+	if remaining <= 0.0:
+		Audit.log(
+			"job_runner",
+			"%s clean done at %s" % [pawn.pawn_name, tile]
+		)
+		t.done = true
+
+
 ## Resolve the patient Pawn node from the NodePath stored in `t.data["patient"]`.
 ## Returns null and logs if the node is absent or no longer valid.
 ## Shared by _tick_rescue and _tick_treat.
diff --git a/scenes/ai/thought_catalog.gd b/scenes/ai/thought_catalog.gd
index b67cfb3..f6c8724 100644
--- a/scenes/ai/thought_catalog.gd
+++ b/scenes/ai/thought_catalog.gd
@@ -129,6 +129,98 @@ static func cold_thought() -> Thought:
 	return t
 
 
+## ── Phase 13 — Room beauty / dirtiness thoughts ─────────────────────────────
+# Synced in Pawn._process_thoughts() after the damp/soaked/cold block.
+# All are PERSISTENT; the sync removes old ones before adding the active tier.
+
+## Positive mood boost when average room beauty >= 4.0.
+## modifier=+4, max_stacks=1, PERSISTENT.
+static func beautiful_room() -> Thought:
+	var t := Thought.new()
+	t.id = &"beautiful_room"
+	t.label = "Beautiful room"
+	t.modifier = 4
+	t.lifetime = Thought.Lifetime.PERSISTENT
+	t.max_stacks = 1
+	return t
+
+
+## Negative mood penalty when average room beauty < 0 (e.g. corpses present, Phase 14).
+## modifier=-3, max_stacks=1, PERSISTENT.
+static func ugly_room() -> Thought:
+	var t := Thought.new()
+	t.id = &"ugly_room"
+	t.label = "Ugly room"
+	t.modifier = -3
+	t.lifetime = Thought.Lifetime.PERSISTENT
+	t.max_stacks = 1
+	return t
+
+
+## Positive mood boost when average room dirtiness < 25 (clean tier).
+## modifier=+2, max_stacks=1, PERSISTENT.
+static func clean_room() -> Thought:
+	var t := Thought.new()
+	t.id = &"clean_room"
+	t.label = "Clean room"
+	t.modifier = 2
+	t.lifetime = Thought.Lifetime.PERSISTENT
+	t.max_stacks = 1
+	return t
+
+
+## Negative mood penalty when average room dirtiness is in dirty tier (25..60).
+## modifier=-3, max_stacks=1, PERSISTENT.
+static func dirty_room() -> Thought:
+	var t := Thought.new()
+	t.id = &"dirty_room"
+	t.label = "Dirty room"
+	t.modifier = -3
+	t.lifetime = Thought.Lifetime.PERSISTENT
+	t.max_stacks = 1
+	return t
+
+
+## Strong negative mood penalty when average room dirtiness >= 60 (filthy tier).
+## modifier=-6, max_stacks=1, PERSISTENT.
+static func filthy_room() -> Thought:
+	var t := Thought.new()
+	t.id = &"filthy_room"
+	t.label = "Filthy room"
+	t.modifier = -6
+	t.lifetime = Thought.Lifetime.PERSISTENT
+	t.max_stacks = 1
+	return t
+
+
+## Positive mood boost after sleeping in an indoor room.
+## modifier=+3, max_stacks=1, EVENT, ~1200 ticks (~60 in-game sec at 1×).
+## Phase 17 wires this into the sleep toil; factory added here for catalog completeness.
+static func slept_in_room() -> Thought:
+	var t := Thought.new()
+	t.id = &"slept_in_room"
+	t.label = "Slept in a room"
+	t.modifier = 3
+	t.lifetime = Thought.Lifetime.EVENT
+	t.ticks_remaining = 1200
+	t.max_stacks = 1
+	return t
+
+
+## Negative mood penalty for eating without a table nearby.
+## modifier=-3, max_stacks=1, EVENT, ~800 ticks (~40 in-game sec at 1×).
+## Phase 17 wires this into the eat toil; factory added here for catalog completeness.
+static func ate_without_table() -> Thought:
+	var t := Thought.new()
+	t.id = &"ate_without_table"
+	t.label = "Ate without a table"
+	t.modifier = -3
+	t.lifetime = Thought.Lifetime.EVENT
+	t.ticks_remaining = 800
+	t.max_stacks = 1
+	return t
+
+
 ## Small mood boost after eating a cooked meal or bread.
 ## Fires in _tick_eat when item_type is TYPE_MEAL or TYPE_BREAD.
 ## Stacks up to 3 (multiple good meals compound, but cap at 3).
diff --git a/scenes/ai/toil.gd b/scenes/ai/toil.gd
index 3d5cb6a..8c90de6 100644
--- a/scenes/ai/toil.gd
+++ b/scenes/ai/toil.gd
@@ -22,6 +22,7 @@ const KIND_EAT: StringName = &"eat"             # Consume pawn.carried_item and
 const KIND_SLEEP: StringName = &"sleep"         # Sleep in a Bed (or on the floor) until pawn.sleep is full
 const KIND_RESCUE: StringName = &"rescue"       # Marker: doctor has visited the downed pawn; single-tick no-op
 const KIND_TREAT: StringName = &"treat"         # Multi-tick: apply medicine until patient HP ≥ revive threshold + no bleeding
+const KIND_CLEAN: StringName = &"clean"         # Multi-tick: reduce dirt on a tile until clean (Phase 13 Cleaning category)
 
 var kind: StringName = KIND_IDLE
 ## Toil-specific params — all values must be int, float, bool, String, Dict, or Array.
@@ -183,6 +184,25 @@ static func treat(patient_path: NodePath) -> Toil:
 	return t
 
 
+## Multi-tick cleaning action on a floor tile.
+## `tile` is the Vector2i world-tile coordinate to clean; stored as int pair for JSON safety.
+## JobRunner._tick_clean reduces DirtinessSystem.dirt_at(tile) by ~2.5/tick until dirt <= 0
+## (40 base ticks per tile; Phase 17 may add skill bonus).
+##
+## data keys:
+##   "clean_x" / "clean_y" — tile coords (ints, JSON-safe)
+##   "started"             — bool; false until first tick
+static func clean_at(tile: Vector2i) -> Toil:
+	var t := Toil.new()
+	t.kind = KIND_CLEAN
+	t.data = {
+		"clean_x": tile.x,
+		"clean_y": tile.y,
+		"started": false,
+	}
+	return t
+
+
 ## Timed crafting action at a Workbench.
 ## `workbench_path` is the NodePath of the Workbench entity (stored as String for JSON safety).
 ## `bill_index` is the index into workbench.bills that this toil should run.
diff --git a/scenes/entities/bed.gd b/scenes/entities/bed.gd
index f2d08b0..ef7ff87 100644
--- a/scenes/entities/bed.gd
+++ b/scenes/entities/bed.gd
@@ -280,3 +280,8 @@ func _complete() -> void:
 	_completed = true
 	queue_redraw()
 	Audit.log("bed", "%s built at %s" % [label_text, tile])
+	# Phase 13 — notify BeautySystem so nearby tile beauty scores update.
+	var bs = World.get("beauty_system")
+	if bs != null:
+		bs.register_furniture(self)
+		bs.recompute_around(tile)
diff --git a/scenes/entities/crop.gd b/scenes/entities/crop.gd
index 37ed160..a86850b 100644
--- a/scenes/entities/crop.gd
+++ b/scenes/entities/crop.gd
@@ -33,6 +33,10 @@ var stage: Stage = Stage.SOWN
 ## Progress within the current growth stage; 0..STAGE_TICKS.
 var stage_progress: int = 0
 
+# Phase 13 — "no growth indoors" rule.  True once we've logged the first
+# indoor detection for this crop instance so we don't flood the audit log.
+var _logged_indoor: bool = false
+
 const ITEM_SCENE: PackedScene = preload("res://scenes/entities/item.tscn")
 
 
@@ -101,10 +105,19 @@ func on_sow_tick() -> void:
 # ── growth ────────────────────────────────────────────────────────────────────
 
 func _on_sim_tick(_n: int) -> void:
-	# Phase 7 simplification: crops always grow regardless of roofing.
-	# Phase 13 "no growth indoors" rule lands when Roof flag system is live.
 	if stage == Stage.READY or stage == Stage.TILLED:
 		return
+	# Phase 13 — crops don't grow indoors (no sunlight under a roof).
+	# World.is_indoor() returns false while RoomDetector has not yet fired, so
+	# outdoor crops planted during boot are unaffected.
+	if World.is_indoor(tile):
+		if not _logged_indoor:
+			Audit.log("crop", "%s at %s won't grow (indoor)" % [crop_kind, tile])
+			_logged_indoor = true
+		return
+	# Crop has moved outdoors or was never indoors — reset the log flag so a
+	# future re-roofing produces another audit line.
+	_logged_indoor = false
 	stage_progress += 1
 	if stage_progress >= STAGE_TICKS:
 		stage_progress = 0
diff --git a/scenes/entities/door.gd b/scenes/entities/door.gd
index 1d85e73..827eb61 100644
--- a/scenes/entities/door.gd
+++ b/scenes/entities/door.gd
@@ -136,7 +136,16 @@ func _draw() -> void:
 func _complete() -> void:
 	_completed = true
 	# Doors are walkable — do NOT call set_cell_walkable(false).
+	# Phase 13 — erase any wall-layer stamp at this tile.  The demo seed
+	# pre-stamps the door slot as a wall so BFS can detect the cabin at boot;
+	# the real door completing supersedes that.  Must happen before register_door
+	# so the BFS in mark_door_tile sees the correct wall-layer state.
+	if World.wall_layer != null:
+		World.wall_layer.erase_cell(tile)
 	# Register so future open/close logic can locate this door by tile.
 	World.register_door(self)
+	# Phase 13 — notify RoomDetector so the door tile is eligible as an
+	# interior boundary tile for room BFS.
+	World.mark_door_tile(tile)
 	queue_redraw()
 	Audit.log("door", "door completed at %s" % tile)
diff --git a/scenes/entities/torch.gd b/scenes/entities/torch.gd
index bf17604..4c8eb3b 100644
--- a/scenes/entities/torch.gd
+++ b/scenes/entities/torch.gd
@@ -243,3 +243,8 @@ func _complete() -> void:
 		_light.enabled = _is_on
 	queue_redraw()
 	Audit.log("torch", "built at %s" % tile)
+	# Phase 13 — notify BeautySystem so nearby tile beauty scores update.
+	var bs = World.get("beauty_system")
+	if bs != null:
+		bs.register_furniture(self)
+		bs.recompute_around(tile)
diff --git a/scenes/entities/workbench.gd b/scenes/entities/workbench.gd
index 9a7c2c6..b6ef18d 100644
--- a/scenes/entities/workbench.gd
+++ b/scenes/entities/workbench.gd
@@ -405,6 +405,13 @@ func _complete() -> void:
 		_light.enabled = is_on()
 	queue_redraw()
 	Audit.log("workbench", "%s built at %s" % [label_text, tile])
+	# Phase 13 — notify BeautySystem so nearby tile beauty scores update.
+	# Hearth gets base beauty 4 (warm glow); other benches get 1.
+	# Beauty lookup key is label_text ("Hearth", "Carpenter", etc.).
+	var bs = World.get("beauty_system")
+	if bs != null:
+		bs.register_furniture(self)
+		bs.recompute_around(tile)
 
 
 # ── Phase 11: internal light helpers ─────────────────────────────────────────
diff --git a/scenes/pawn/pawn.gd b/scenes/pawn/pawn.gd
index 314ead9..e4a948a 100644
--- a/scenes/pawn/pawn.gd
+++ b/scenes/pawn/pawn.gd
@@ -136,6 +136,12 @@ var statuses: Array = []   # Array[Status]
 var _wet_accum: float = 0.0
 var _cold_accum: float = 0.0
 
+# Phase 13 — shelter debug tracking.
+## When SHELTER_DEBUG is true, any false→true or true→false transition in
+## _is_sheltered() emits an Audit.log line.  Off by default — debug noise.
+const SHELTER_DEBUG: bool = false
+var _shelter_prev: bool = false
+
 var _path: Array[Vector2i] = []
 var _step_progress: float = 0.0
 var _selected: bool = false
@@ -400,6 +406,9 @@ func _process_thoughts() -> void:
 	_sync_persistent_thought(&"soaked", has_status(&"wet") and _wet_severity() == StatusCatalog.WET_SOAKED_LEVEL, ThoughtCatalog.soaked())
 	# Phase 12 — cold mood thought (any cold severity triggers the single cold thought).
 	_sync_persistent_thought(&"cold", has_status(&"cold"), ThoughtCatalog.cold_thought())
+	# Phase 13 — room beauty and dirtiness thoughts.
+	# Defensive: World.room_at_tile returns null if rooms are empty (Agent A may land later).
+	_sync_room_thoughts()
 	# 3. Recompute if EVENT thoughts expired (persistent syncs call _recompute_mood internally).
 	if dirty:
 		_recompute_mood()
@@ -407,6 +416,62 @@ func _process_thoughts() -> void:
 	_process_sulking()
 
 
+## Phase 13 — sync beauty and dirtiness room thoughts for this pawn's current tile.
+## Called from _process_thoughts() after the cold/damp/soaked block.
+## Defensive: returns early if rooms or the beauty/dirtiness systems are not yet wired
+## (Agent A's RoomDetector may land slightly after this code during startup).
+##
+## Beauty thoughts (mutually exclusive — only one fires):
+##   avg beauty >= 4.0 → beautiful_room
+##   avg beauty <  0.0 → ugly_room (Phase 14 corpses drive this below 0)
+##   else              → neither
+##
+## Dirtiness thoughts (mutually exclusive — only one fires):
+##   avg dirt <  25 → clean_room
+##   avg dirt 25..60 → dirty_room
+##   avg dirt >= 60  → filthy_room
+func _sync_room_thoughts() -> void:
+	var room = World.room_at_tile(tile)
+
+	# ── no room (outdoors or RoomDetector not yet live) → clear all room thoughts ──
+	if room == null:
+		_sync_persistent_thought(&"beautiful_room", false, ThoughtCatalog.beautiful_room())
+		_sync_persistent_thought(&"ugly_room",      false, ThoughtCatalog.ugly_room())
+		_sync_persistent_thought(&"clean_room",     false, ThoughtCatalog.clean_room())
+		_sync_persistent_thought(&"dirty_room",     false, ThoughtCatalog.dirty_room())
+		_sync_persistent_thought(&"filthy_room",    false, ThoughtCatalog.filthy_room())
+		return
+
+	# ── beauty ──────────────────────────────────────────────────────────────────
+	var avg_beauty: float = 0.0
+	var bs = World.get("beauty_system")
+	if bs != null and room.tiles.size() > 0:
+		var beauty_sum: float = 0.0
+		for rt in room.tiles:
+			beauty_sum += bs.beauty_at(rt)
+		avg_beauty = beauty_sum / float(room.tiles.size())
+
+	_sync_persistent_thought(&"beautiful_room", avg_beauty >= 4.0, ThoughtCatalog.beautiful_room())
+	_sync_persistent_thought(&"ugly_room",      avg_beauty < 0.0,  ThoughtCatalog.ugly_room())
+
+	# ── dirtiness ───────────────────────────────────────────────────────────────
+	var avg_dirt: float = 0.0
+	var ds = World.get("dirtiness_system")
+	if ds != null and room.tiles.size() > 0:
+		var dirt_sum: float = 0.0
+		for rt in room.tiles:
+			dirt_sum += ds.dirt_at(rt)
+		avg_dirt = dirt_sum / float(room.tiles.size())
+
+	# Mutually exclusive — only one fires (filthy wins over dirty wins over clean).
+	var is_filthy: bool = avg_dirt >= 60.0
+	var is_dirty:  bool = avg_dirt >= 25.0 and not is_filthy
+	var is_clean:  bool = avg_dirt < 25.0
+	_sync_persistent_thought(&"filthy_room", is_filthy, ThoughtCatalog.filthy_room())
+	_sync_persistent_thought(&"dirty_room",  is_dirty,  ThoughtCatalog.dirty_room())
+	_sync_persistent_thought(&"clean_room",  is_clean,  ThoughtCatalog.clean_room())
+
+
 ## Add or remove a PERSISTENT thought based on a boolean state flag.
 ## Calls add_thought() / remove_thought_by_id() (which recompute mood) only
 ## when the presence actually needs to change — avoids redundant recomputes.
@@ -590,12 +655,25 @@ func _sync_cold_status() -> void:
 				break
 
 
-## Phase 12 — returns true if the pawn's current tile has a floor beneath it.
-## This is a Phase 13 stand-in for full Room/Roof detection.  A tile is considered
-## sheltered when World.floor_layer reports a valid cell at the pawn's tile position.
-## Replace with Room.contains(tile) once the Room BFS system lands (Phase 13+).
+## Phase 13 — returns true if the pawn's current tile is inside an enclosed,
+## roofed Room (via World.is_indoor).  Falls back to the Phase 12 has-floor proxy
+## during the brief window before RoomDetector populates the registry (boot,
+## mid-build, cabin not-yet-enclosed).  The fallback is graceful enough for those
+## transient states and produces no false positives on open terrain.
+##
+## Callers: _tick_wet() and _tick_cold() both call this once per sim tick.
+## If SHELTER_DEBUG is true, false→true and true→false transitions emit Audit lines.
 func _is_sheltered() -> bool:
-	return World.floor_layer.get_cell_source_id(tile) != -1
+	var sheltered: bool
+	if World.is_indoor(tile):
+		sheltered = true
+	else:
+		sheltered = World.floor_layer.get_cell_source_id(tile) != -1
+	if SHELTER_DEBUG and sheltered != _shelter_prev:
+		var direction := "→sheltered" if sheltered else "→unsheltered"
+		Audit.log("pawn", "%s shelter transition %s at %s" % [pawn_name, direction, tile])
+	_shelter_prev = sheltered
+	return sheltered
 
 
 # ── save / load ─────────────────────────────────────────────────────────────
diff --git a/scenes/world/beauty_system.gd b/scenes/world/beauty_system.gd
new file mode 100644
index 0000000..c905858
--- /dev/null
+++ b/scenes/world/beauty_system.gd
@@ -0,0 +1,179 @@
+class_name BeautySystem extends Node
+## Phase 13 — per-tile beauty score, derived from nearby furniture and its quality.
+##
+## beauty_map stores only tiles with non-zero beauty (sparse). Default = 0.
+##
+## Beauty contributions (base × quality_multiplier, spread over a radius):
+##   Bed        +2  radius 3
+##   Workbench  +1  radius 3
+##   Torch      +3  radius 3
+##   Hearth     +4  radius 3  (warm glow variant of Workbench by label_text)
+##
+## Falloff: linear from base at the source tile to 0 at radius+1.
+##   Contribution at distance d = base_beauty × multiplier × max(0, 1 - d/radius)
+##
+## Usage:
+##   Call recompute_around(tile) after any furniture build or removal.
+##   Query beauty_at(tile) for the aggregated beauty value at a tile.
+##   EventBus.tile_beauty_changed fires for every tile whose beauty changes.
+##
+## Wire as child of the World scene (after Pathfinder). world.gd exposes the
+## instance on the World autoload as World.beauty_system for entity code.
+##
+## Negative beauty (corpses, etc.) is Phase 14 work — just expose bump() then.
+
+## Sparse map: only tiles with non-zero beauty are stored.
+## Keys = Vector2i tile coords; Values = float beauty score.
+var beauty_map: Dictionary = {}
+
+## Registered furniture entities. Each must expose:
+##   tile: Vector2i
+##   is_completed() -> bool   (or _completed var — checked via has_method)
+##   label_text: String       (for Hearth vs generic Workbench beauty)
+## and optionally:
+##   quality: int             (Item.Quality int; defaults to NORMAL=1 if absent)
+var _furniture: Array = []
+
+## Base beauty values by duck-typed entity type (label_text takes priority for Workbench).
+const BASE_BEAUTY: Dictionary = {
+	"Bed":        2.0,
+	"Torch":      3.0,
+	"Hearth":     4.0,
+	"Workbench":  1.0,   # fallback for Carpenter / Smelter / Millstone etc.
+	"Carpenter":  1.0,
+	"Smelter":    1.0,
+	"Millstone":  1.0,
+}
+
+## Default beauty spread radius in tiles.
+const DEFAULT_RADIUS: int = 3
+
+
+# ── public API ────────────────────────────────────────────────────────────────
+
+## Returns the aggregated beauty score for `tile`.  0 if tile is not in the map.
+func beauty_at(tile: Vector2i) -> float:
+	return float(beauty_map.get(tile, 0.0))
+
+
+## Register a furniture entity so BeautySystem tracks it.
+## Call from the entity's _ready() or on_build_complete hook.
+func register_furniture(entity) -> void:
+	if not _furniture.has(entity):
+		_furniture.append(entity)
+
+
+## Unregister a furniture entity.
+## Call from the entity's _exit_tree().
+func unregister_furniture(entity) -> void:
+	_furniture.erase(entity)
+
+
+## Recompute beauty for all tiles within `radius` of `tile`.
+## Call after a furniture piece is built or removed.
+## Emits EventBus.tile_beauty_changed for every tile whose value changes.
+func recompute_around(tile: Vector2i, radius: int = DEFAULT_RADIUS) -> void:
+	# Collect all tiles in the affected area (square bbox, then clamp to map).
+	var affected_tiles: Array[Vector2i] = []
+	for dy in range(-radius, radius + 1):
+		for dx in range(-radius, radius + 1):
+			affected_tiles.append(Vector2i(tile.x + dx, tile.y + dy))
+	_recompute_tiles(affected_tiles)
+	Audit.log("beauty", "recompute_around %s radius=%d" % [tile, radius])
+
+
+## Full recompute across all tracked furniture. Useful on load or large changes.
+## Returns immediately and logs if no furniture is registered.
+func recompute_all() -> void:
+	if _furniture.is_empty():
+		return
+	# Collect every tile that is currently in the map OR within reach of any furniture.
+	var dirty_tiles: Dictionary = {}
+	for tile in beauty_map.keys():
+		dirty_tiles[tile] = true
+	for entity in _furniture:
+		if not _entity_completed(entity):
+			continue
+		var t: Vector2i = entity.tile
+		for dy in range(-DEFAULT_RADIUS, DEFAULT_RADIUS + 1):
+			for dx in range(-DEFAULT_RADIUS, DEFAULT_RADIUS + 1):
+				dirty_tiles[Vector2i(t.x + dx, t.y + dy)] = true
+	_recompute_tiles(dirty_tiles.keys())
+
+
+# ── internal ──────────────────────────────────────────────────────────────────
+
+## Recompute beauty for each tile in `tiles` from scratch.
+## Emits tile_beauty_changed for any tile whose value changed.
+func _recompute_tiles(tiles: Array) -> void:
+	for tile in tiles:
+		var new_val: float = _compute_beauty_at(tile)
+		var old_val: float = float(beauty_map.get(tile, 0.0))
+		if is_equal_approx(new_val, old_val):
+			continue
+		if new_val == 0.0:
+			beauty_map.erase(tile)
+		else:
+			beauty_map[tile] = new_val
+		EventBus.tile_beauty_changed.emit(tile, new_val)
+		Audit.log("beauty", "tile %s → %.2f" % [tile, new_val])
+
+
+## Sum all furniture contributions at a given tile.
+func _compute_beauty_at(tile: Vector2i) -> float:
+	var total: float = 0.0
+	for entity in _furniture:
+		if not _entity_completed(entity):
+			continue
+		var et: Vector2i = entity.tile
+		var dist: int = abs(et.x - tile.x) + abs(et.y - tile.y)
+		if dist > DEFAULT_RADIUS:
+			continue
+		var base: float = _base_beauty_for(entity)
+		if base == 0.0:
+			continue
+		var multiplier: float = _quality_multiplier_for(entity)
+		var falloff: float = maxf(0.0, 1.0 - float(dist) / float(DEFAULT_RADIUS))
+		total += base * multiplier * falloff
+	return total
+
+
+## Returns the base beauty value for an entity by its label_text (or type name).
+func _base_beauty_for(entity) -> float:
+	var label: String = ""
+	if "label_text" in entity:
+		label = str(entity.label_text)
+	# Check specific labels first, then fall back to class_name.
+	if BASE_BEAUTY.has(label):
+		return float(BASE_BEAUTY[label])
+	# Fallback by class_name string (e.g. "Bed", "Torch").
+	var cname: String = entity.get_class()
+	if BASE_BEAUTY.has(cname):
+		return float(BASE_BEAUTY[cname])
+	return 0.0
+
+
+## Returns the quality multiplier for an entity.
+## Uses Item.Quality int (0=SHODDY..4=LEGENDARY) → 0.5/1.0/1.5/2.0/2.5.
+## Defaults to 1.0 (NORMAL) if the entity has no quality field.
+func _quality_multiplier_for(entity) -> float:
+	var q: int = 1  # NORMAL default
+	if "quality" in entity:
+		q = int(entity.quality)
+	match q:
+		0:  return 0.5   # SHODDY
+		1:  return 1.0   # NORMAL
+		2:  return 1.5   # EXCELLENT
+		3:  return 2.0   # MASTERWORK
+		4:  return 2.5   # LEGENDARY
+		_:  return 1.0
+
+
+## Returns true if `entity` has finished building.
+## Checks the _completed bool directly (all furniture exposes is_completed() and the var).
+func _entity_completed(entity) -> bool:
+	if entity.has_method("is_completed"):
+		return entity.is_completed()
+	if "_completed" in entity:
+		return bool(entity._completed)
+	return true   # assume complete if we can't tell
diff --git a/scenes/world/beauty_system.gd.uid b/scenes/world/beauty_system.gd.uid
new file mode 100644
index 0000000..e001383
--- /dev/null
+++ b/scenes/world/beauty_system.gd.uid
@@ -0,0 +1 @@
+uid://bc7s1jr1y01o
diff --git a/scenes/world/designation.gd b/scenes/world/designation.gd
index cdec554..2b01ef2 100644
--- a/scenes/world/designation.gd
+++ b/scenes/world/designation.gd
@@ -17,14 +17,19 @@ const TOOL_NONE:        StringName = &"none"
 const TOOL_BUILD_WALL:  StringName = &"build_wall"
 const TOOL_BUILD_FLOOR: StringName = &"build_floor"
 const TOOL_BUILD_DOOR:  StringName = &"build_door"
+# Phase 13 — no-roof designation: painted tiles become courtyards; RoomDetector
+# excludes them from auto-roofing.  Calls World.toggle_no_roof_at() on apply.
+const TOOL_NO_ROOF:     StringName = &"no_roof"
 
 # Atlas coords on the shared placeholder tileset (source 0).
 # build_wall → stone-grey (2, 0); build_floor → dirt-brown (1, 0).
 # build_door → dark stone (3, 0) so the ghost reads visually distinct from walls.
+# no_roof → grass (0, 0) with the designation layer modulate tinting it visibly.
 const _ATLAS_BY_TOOL: Dictionary = {
 	&"build_wall":  Vector2i(2, 0),
 	&"build_floor": Vector2i(1, 0),
 	&"build_door":  Vector2i(3, 0),
+	&"no_roof":     Vector2i(0, 0),
 }
 
 # Placeholder source ID — mirrors World.PLACEHOLDER_SOURCE_ID.
@@ -63,7 +68,7 @@ func bind(paint_layer: TileMapLayer, selection: Selection = null) -> void:
 ## Activate a paint tool.  Pass TOOL_NONE to deactivate.
 func set_active_tool(tool: StringName) -> void:
 	assert(
-		tool in [TOOL_NONE, TOOL_BUILD_WALL, TOOL_BUILD_FLOOR, TOOL_BUILD_DOOR],
+		tool in [TOOL_NONE, TOOL_BUILD_WALL, TOOL_BUILD_FLOOR, TOOL_BUILD_DOOR, TOOL_NO_ROOF],
 		"Designation.set_active_tool: unknown tool '%s'" % tool
 	)
 	_tool = tool
@@ -153,6 +158,13 @@ func _apply_ghost(cell: Vector2i) -> void:
 	var ok: bool = _cell_is_placeable(cell)
 	_paint_layer.modulate = Color(0.4, 1.0, 0.4, 0.7) if ok else Color(1.0, 0.4, 0.4, 0.7)
 
+	# Phase 13 — no-roof tool: toggle the tile in World.no_roof_cells and
+	# trigger an immediate room recompute.  No build job is queued.
+	if _tool == TOOL_NO_ROOF:
+		World.toggle_no_roof_at(cell)
+		Audit.log("designation", "no_roof toggled at %s" % cell)
+		return
+
 	designation_added.emit(cell, _tool)
 	EventBus.designation_added.emit(cell, _tool)
 	Audit.log("designation", "painted %s at %s (placeable=%s)" % [_tool, cell, ok])
diff --git a/scenes/world/dirtiness_system.gd b/scenes/world/dirtiness_system.gd
new file mode 100644
index 0000000..dae48ac
--- /dev/null
+++ b/scenes/world/dirtiness_system.gd
@@ -0,0 +1,109 @@
+class_name DirtinessSystem extends Node
+## Phase 13 — per-tile dirtiness accumulation and tier tracking.
+##
+## dirt_map: Dictionary[Vector2i, float], 0..100 scale.  Only tiles with non-zero
+## dirt are keyed (sparse).
+##
+## Public API:
+##   bump(tile, amount)  — add dirtiness to a tile. Positive adds dirt; use
+##                         negative values to reduce (cleaning does this via
+##                         bump_clean). Phase 14 calls bump(tile, +5) per hour
+##                         for corpse decay and bump(tile, +20) for combat blood.
+##   bump_clean(tile, amount) — specialised helper for the CleaningProvider;
+##                         reduces dirt and removes the tile from the map at 0.
+##   dirt_at(tile)       — returns the current dirtiness for a tile (0.0 default).
+##
+## Tier thresholds (per design.md):
+##   Clean    < 25
+##   Dirty   25..60
+##   Filthy  >= 60
+##
+## EventBus.tile_dirtiness_changed fires on TIER crossings only, not every bump.
+## This keeps signal volume low since bumps fire 20×/s per pawn crossing.
+##
+## Pawn tile-change hook:
+##   World scene calls bump_pawn_traffic(tile, indoor) each time a pawn advances
+##   a tile. Indoor traffic adds 0.2; outdoor-tracked-in adds 0.5.
+##   (world.gd bridges _advance_walk → DirtinessSystem via the arrived_at_destination
+##   signal on each Pawn — wired in world.gd _spawn_sample_pawns / _on_pawn_ready.)
+##
+## Wire as child of the World scene (after Pathfinder). world.gd exposes the
+## instance on the World autoload as World.dirtiness_system for entity code.
+
+## Sparse map: only tiles with non-zero dirt are stored.
+## Keys = Vector2i tile coords; Values = float in [0, 100].
+var dirt_map: Dictionary = {}
+
+## Tier boundaries (thresholds match design.md; tune Phase 20).
+const DIRT_DIRTY_THRESHOLD:  float = 25.0
+const DIRT_FILTHY_THRESHOLD: float = 60.0
+
+## Traffic bump amounts per pawn step.
+const BUMP_OUTDOOR_TRACKED: float = 0.5   # boots bringing dirt in from outside
+const BUMP_INDOOR_TRAFFIC:  float = 0.2   # indoor walking
+
+
+# ── public API ────────────────────────────────────────────────────────────────
+
+## Returns the dirtiness score for `tile` (0.0 if clean / not in map).
+func dirt_at(tile: Vector2i) -> float:
+	return float(dirt_map.get(tile, 0.0))
+
+
+## Add `amount` of dirt to `tile`.  Clamped to [0, 100].
+## Emits EventBus.tile_dirtiness_changed when a tier boundary is crossed.
+## Phase 14 calls this for blood (+20) and corpse decay (+5/h).
+func bump(tile: Vector2i, amount: float) -> void:
+	var old_val: float = float(dirt_map.get(tile, 0.0))
+	var new_val: float = clampf(old_val + amount, 0.0, 100.0)
+	if is_equal_approx(new_val, old_val):
+		return
+	_set_dirt(tile, old_val, new_val)
+
+
+## Reduce dirt by `amount`, flooring at 0.  Removes tile from map when clean.
+## Used by CleaningProvider's KIND_CLEAN toil each tick.
+func bump_clean(tile: Vector2i, amount: float) -> void:
+	var old_val: float = float(dirt_map.get(tile, 0.0))
+	if old_val <= 0.0:
+		return
+	var new_val: float = maxf(0.0, old_val - amount)
+	_set_dirt(tile, old_val, new_val)
+
+
+## Traffic-driven dirt bump.  Called by World when a pawn arrives at a new tile.
+## `indoor` = true when the tile is inside a roofed room (World.is_indoor check).
+func bump_pawn_traffic(tile: Vector2i, indoor: bool) -> void:
+	var amount := BUMP_INDOOR_TRAFFIC if indoor else BUMP_OUTDOOR_TRACKED
+	bump(tile, amount)
+
+
+# ── internal ──────────────────────────────────────────────────────────────────
+
+## Apply a dirt change from old_val to new_val for `tile`.
+## Updates the map and emits the tier-crossing signal when the tier changes.
+func _set_dirt(tile: Vector2i, old_val: float, new_val: float) -> void:
+	var old_tier: int = _tier_for(old_val)
+	var new_tier: int = _tier_for(new_val)
+
+	if new_val <= 0.0:
+		dirt_map.erase(tile)
+	else:
+		dirt_map[tile] = new_val
+
+	if old_tier != new_tier:
+		EventBus.tile_dirtiness_changed.emit(tile, new_val)
+		Audit.log(
+			"dirtiness",
+			"tile %s tier %d → %d (dirt=%.1f)" % [tile, old_tier, new_tier, new_val]
+		)
+
+
+## Returns the dirtiness tier for a given value.
+##   0 = clean, 1 = dirty, 2 = filthy.
+func _tier_for(val: float) -> int:
+	if val >= DIRT_FILTHY_THRESHOLD:
+		return 2
+	if val >= DIRT_DIRTY_THRESHOLD:
+		return 1
+	return 0
diff --git a/scenes/world/dirtiness_system.gd.uid b/scenes/world/dirtiness_system.gd.uid
new file mode 100644
index 0000000..63d284c
--- /dev/null
+++ b/scenes/world/dirtiness_system.gd.uid
@@ -0,0 +1 @@
+uid://dtgne6uq4wdsf
diff --git a/scenes/world/indoor_tint_overlay.gd b/scenes/world/indoor_tint_overlay.gd
new file mode 100644
index 0000000..a7bdca9
--- /dev/null
+++ b/scenes/world/indoor_tint_overlay.gd
@@ -0,0 +1,52 @@
+extends Node2D
+## Phase 13 — subtle warm overlay drawn over every tile that belongs to an
+## enclosed, roofed Room.
+##
+## Rendering model: Node2D _draw() filled on EventBus.room_changed only — NOT
+## every render frame.  At MVP scale (< 20 rooms × ~10 tiles each) that's at
+## most ~200 draw_rect calls per room-topology change, which is negligible.
+##
+## Placement: child of the World Node2D, z_index = 3 (above Floor layer at 1,
+## same z as Designation — kept above floor, below pawns/entities at 4+).
+##
+## The overlay does NOT use CanvasModulate or shaders; a plain translucent rect
+## per tile is correct, cheap, and doesn't interact with the day/night modulate.
+##
+## When the room registry is empty (boot, before RoomDetector fires), _draw()
+## simply does nothing — graceful degradation.
+
+class_name IndoorTintOverlay
+
+## Warm candlelight tint.  Alpha is deliberately very low (0.10) so the floor
+## and entity sprites beneath remain fully legible.
+const INDOOR_COLOR: Color = Color(1.0, 0.95, 0.85, 0.10)
+
+const TILE_SIZE_PX: int = 16  ## Mirror of World.TILE_SIZE_PX; standalone to avoid circular dep.
+
+
+func _ready() -> void:
+	z_index = 3
+	# Listen for room topology changes and redraw.  room_changed fires when any
+	# Room is created, destroyed, or recomputed by RoomDetector (Agent A).
+	EventBus.room_changed.connect(_on_room_changed)
+
+
+func _on_room_changed(_room_id: int) -> void:
+	queue_redraw()
+
+
+func _draw() -> void:
+	# Iterate every room in the registry.  Only draw tiles belonging to roofed rooms.
+	for id in World.rooms:
+		var r = World.rooms[id]
+		if not r.is_under_roof:
+			continue
+		# r.tiles is an Array[Vector2i] per room.gd contract.
+		for t in r.tiles:
+			var rect := Rect2(
+				float(t.x * TILE_SIZE_PX),
+				float(t.y * TILE_SIZE_PX),
+				float(TILE_SIZE_PX),
+				float(TILE_SIZE_PX)
+			)
+			draw_rect(rect, INDOOR_COLOR)
diff --git a/scenes/world/indoor_tint_overlay.gd.uid b/scenes/world/indoor_tint_overlay.gd.uid
new file mode 100644
index 0000000..d80b5f9
--- /dev/null
+++ b/scenes/world/indoor_tint_overlay.gd.uid
@@ -0,0 +1 @@
+uid://bg0fqaxphkieo
diff --git a/scenes/world/room.gd b/scenes/world/room.gd
new file mode 100644
index 0000000..0d0c37f
--- /dev/null
+++ b/scenes/world/room.gd
@@ -0,0 +1,63 @@
+class_name Room
+## Phase 13 — enclosed-space data class.
+##
+## A Room is a set of contiguous tiles enclosed by walls (and/or doors), discovered
+## by RoomDetector's BFS. Once discovered, the room may be auto-roofed (if
+## `tile_count() <= ROOM_AUTOROOF_CAP`) and its tiles count as "indoor" for
+## purposes of weather shelter, beauty aggregation, dirtiness, and room thoughts.
+##
+## A room with tile_count() > ROOM_AUTOROOF_CAP is detected but NOT roofed; it
+## triggers EventBus.room_too_large so UI can surface the "split with an interior
+## wall" banner.  The cap is 16 per the 2026-05-11 decision (memory.md).
+##
+## Construction is owned by RoomDetector; entities should NEVER instantiate
+## Rooms directly — query World.room_at_tile() instead.
+
+const ROOM_AUTOROOF_CAP: int = 16
+
+## Stable identity, assigned by RoomDetector on creation.  Used as the value
+## carried by EventBus.room_changed(room_id).  Invalidated on destroy.
+var id: int = -1
+
+## Every floor/door tile inside this room.  Walls themselves are NOT included —
+## walls are the boundary, not the interior.
+var tiles: Array[Vector2i] = []
+
+## Cached AABB of `tiles`.  Useful for cheap point-in-room rejection before the
+## full tiles-array sweep.
+var bounds: Rect2i = Rect2i()
+
+## True when RoomDetector applied auto-roof — i.e. tile_count() <= ROOM_AUTOROOF_CAP
+## AND the room is fully enclosed.  Drives shelter / indoor-tint checks.
+var is_under_roof: bool = false
+
+
+## Returns the number of interior tiles (NOT including bounding walls).
+func tile_count() -> int:
+	return tiles.size()
+
+
+## True if `tile` is one of this room's interior tiles.  Uses bounds first
+## as a cheap reject before falling back to a linear search.
+func contains_tile(tile: Vector2i) -> bool:
+	if not bounds.has_point(tile):
+		return false
+	return tile in tiles
+
+
+## Recompute the bounds Rect2i from the current tiles array.  Called by
+## RoomDetector after populating tiles.
+func recompute_bounds() -> void:
+	if tiles.is_empty():
+		bounds = Rect2i()
+		return
+	var min_x: int = tiles[0].x
+	var min_y: int = tiles[0].y
+	var max_x: int = tiles[0].x
+	var max_y: int = tiles[0].y
+	for t in tiles:
+		if t.x < min_x: min_x = t.x
+		if t.y < min_y: min_y = t.y
+		if t.x > max_x: max_x = t.x
+		if t.y > max_y: max_y = t.y
+	bounds = Rect2i(min_x, min_y, max_x - min_x + 1, max_y - min_y + 1)
diff --git a/scenes/world/room.gd.uid b/scenes/world/room.gd.uid
new file mode 100644
index 0000000..1843362
--- /dev/null
+++ b/scenes/world/room.gd.uid
@@ -0,0 +1 @@
+uid://bpcf16gi3g05d
diff --git a/scenes/world/room_detector.gd b/scenes/world/room_detector.gd
new file mode 100644
index 0000000..8b5dda9
--- /dev/null
+++ b/scenes/world/room_detector.gd
@@ -0,0 +1,256 @@
+class_name RoomDetector extends Node
+## Phase 13 — BFS-based room detection, auto-roof, and no-roof exclusion.
+##
+## RoomDetector owns the lifecycle of Room objects: it creates them, destroys
+## them when the geometry changes, and writes `World.rooms`.  Nothing else
+## should mutate `World.rooms` directly.
+##
+## Entry point: call `recompute_around(tile)` after any wall/floor/door build or
+## removal.  World._ready() calls it once for the cabin demo seed so MCP runtime
+## tests can see a Room in the registry immediately after boot.
+##
+## No-roof exclusion: tiles in `World.no_roof_cells` are treated as "open sky"
+## during BFS.  If any such tile appears in a BFS result the room is detected
+## but marked `is_under_roof = false` regardless of size.
+##
+## Delegation model: this node IS a child of the World scene node (not the
+## World autoload).  `World.room_detector` is a convenience reference set in
+## World._ready() so autoloads can call recompute_around().
+
+## Give enough BFS headroom to detect rooms up to 4× the auto-roof cap.
+## BFS counts exceeding this without finding a wall ring → treated as outdoor.
+const BFS_CAP_FOR_ROOM: int = Room.ROOM_AUTOROOF_CAP * 4
+
+## Radius (in tiles) around a changed tile to re-evaluate.
+const RECOMPUTE_RADIUS: int = 3
+
+## 4-directional offsets (no diagonals — matches pathfinder convention).
+const _DIRS: Array[Vector2i] = [
+	Vector2i(0, -1), Vector2i(0, 1), Vector2i(-1, 0), Vector2i(1, 0),
+]
+
+## Map bounds — set by World._ready() after pathfinder is configured.
+var _map_size: Vector2i = Vector2i(80, 80)
+
+## Monotonically-increasing id counter.  Invalidated ids are never reused.
+var _next_room_id: int = 0
+
+
+# ── public API ────────────────────────────────────────────────────────────────
+
+## Set the canonical map size so BFS can detect edge-of-map as "outdoor".
+func setup(map_size: Vector2i) -> void:
+	_map_size = map_size
+
+
+## Main entry point.  Call after any wall/floor/door change at `changed_tile`.
+## Invalidates rooms that overlap the 3-tile radius, then re-BFS from every
+## open floor tile in that radius.
+func recompute_around(changed_tile: Vector2i) -> void:
+	# 1. Gather the recompute radius set.
+	var radius_tiles: Array[Vector2i] = _tiles_in_radius(changed_tile, RECOMPUTE_RADIUS)
+
+	# 2. Destroy any Room whose tiles overlap the radius.
+	_invalidate_rooms_touching(radius_tiles)
+
+	# 3. For each floor or door tile in the radius that isn't a wall, try a BFS.
+	#    Track which tiles we've already started a BFS from so we don't start two
+	#    BFS runs from tiles that will find the same room.
+	var already_claimed: Dictionary = {}  # Vector2i → true, for tiles inside a found room.
+
+	for candidate in radius_tiles:
+		if already_claimed.has(candidate):
+			continue
+		if not _is_floor_or_door(candidate):
+			continue
+
+		var result: Dictionary = _bfs_room(candidate)
+		if result.is_empty():
+			continue  # outdoor or BFS cap hit without enclosure
+
+		var found_tiles: Array[Vector2i] = result["tiles"]
+		var has_no_roof: bool = result["has_no_roof"]
+
+		# Mark all found tiles so sibling candidates skip them.
+		for t in found_tiles:
+			already_claimed[t] = true
+
+		_create_room(found_tiles, has_no_roof)
+
+
+# ── room invalidation ─────────────────────────────────────────────────────────
+
+func _invalidate_rooms_touching(radius_tiles: Array[Vector2i]) -> void:
+	var radius_set: Dictionary = {}
+	for t in radius_tiles:
+		radius_set[t] = true
+
+	# Collect ids to destroy (can't erase while iterating).
+	var to_destroy: Array[int] = []
+	for id in World.rooms:
+		var r: Room = World.rooms[id]
+		for t in r.tiles:
+			if radius_set.has(t):
+				to_destroy.append(id)
+				break
+
+	for id in to_destroy:
+		World.rooms.erase(id)
+		EventBus.room_changed.emit(id)
+		Audit.log("room", "destroyed room #%d" % id)
+
+
+# ── BFS ───────────────────────────────────────────────────────────────────────
+
+## Returns a dict {"tiles": Array[Vector2i], "has_no_roof": bool} when a clean
+## enclosed room is found.  Returns an empty dict for outdoor / over-cap areas.
+##
+## Door semantics: a door tile is a BOUNDARY like a wall — BFS stops at it and
+## does NOT expand through it to the outside.  The door tile IS included in the
+## room's tile list (it's part of the interior enclosure).  This matches the
+## spec: "treat door tiles as boundary cells" that stop the BFS but are counted.
+func _bfs_room(start: Vector2i) -> Dictionary:
+	# interior_tiles: tiles that are inside the room (floor + door tiles).
+	# boundary_visited: tiles that stopped BFS expansion (walls + doors), tracked
+	# so we don't re-process them as neighbours.
+	var interior_visited: Dictionary = {}   # Vector2i → true
+	var boundary_visited: Dictionary = {}   # Vector2i → true (walls + doors)
+	var queue: Array[Vector2i] = [start]
+	interior_visited[start] = true
+	var has_no_roof: bool = false
+
+	while queue.size() > 0:
+		if interior_visited.size() > BFS_CAP_FOR_ROOM:
+			# Exceeded cap without finding a closed wall ring → treat as outdoor.
+			return {}
+
+		var current: Vector2i = queue.pop_front()
+
+		# Check for no-roof designation.
+		if World.no_roof_cells.has(current):
+			has_no_roof = true
+
+		for dir in _DIRS:
+			var neighbour: Vector2i = current + dir
+
+			# Already classified — skip.
+			if interior_visited.has(neighbour) or boundary_visited.has(neighbour):
+				continue
+
+			# Map edge → open sky → discard entire BFS.
+			if not _in_bounds(neighbour):
+				return {}
+
+			if _is_wall(neighbour):
+				# Wall is a valid enclosing boundary — mark as boundary, stop expansion.
+				boundary_visited[neighbour] = true
+				continue
+
+			if _is_door(neighbour):
+				# Door acts as a boundary that stops BFS from escaping, but the door
+				# tile itself is part of the room interior.  Add to interior but do
+				# NOT expand through it — treat it like a wall for expansion purposes.
+				interior_visited[neighbour] = true
+				# Do NOT append to queue — door blocks outward traversal.
+				continue
+
+			if _is_floor(neighbour):
+				interior_visited[neighbour] = true
+				queue.append(neighbour)
+			else:
+				# Bare terrain → open sky → discard.
+				return {}
+
+	if interior_visited.is_empty():
+		return {}
+
+	var interior: Array[Vector2i] = []
+	for t: Vector2i in interior_visited.keys():
+		interior.append(t)
+
+	return {"tiles": interior, "has_no_roof": has_no_roof}
+
+
+# ── room creation ─────────────────────────────────────────────────────────────
+
+func _create_room(interior: Array[Vector2i], has_no_roof: bool) -> void:
+	var r := Room.new()
+	r.id = _next_room_id
+	_next_room_id += 1
+	r.tiles = interior
+	r.recompute_bounds()
+
+	var count: int = interior.size()
+	var top_left: Vector2i = Vector2i(r.bounds.position.x, r.bounds.position.y)
+
+	if has_no_roof:
+		# No-roof tile inside — courtyard; detects as room but stays open.
+		r.is_under_roof = false
+		World.rooms[r.id] = r
+		EventBus.room_changed.emit(r.id)
+		Audit.log("room", "discovered #%d size=%d at bounds=%s (no-roof courtyard)" % [
+			r.id, count, r.bounds
+		])
+
+	elif count <= Room.ROOM_AUTOROOF_CAP:
+		r.is_under_roof = true
+		World.rooms[r.id] = r
+		EventBus.room_changed.emit(r.id)
+		Audit.log("room", "discovered #%d size=%d at bounds=%s (auto-roofed)" % [
+			r.id, count, r.bounds
+		])
+
+	else:
+		# Clean enclosure but over the auto-roof cap.
+		r.is_under_roof = false
+		World.rooms[r.id] = r
+		EventBus.room_too_large.emit(top_left, count)
+		EventBus.room_changed.emit(r.id)
+		Audit.log("room", "WARNING room #%d too large size=%d at bounds=%s (roof suppressed)" % [
+			r.id, count, r.bounds
+		])
+
+
+# ── tile classification helpers ───────────────────────────────────────────────
+
+func _in_bounds(tile: Vector2i) -> bool:
+	return tile.x >= 0 and tile.y >= 0 and tile.x < _map_size.x and tile.y < _map_size.y
+
+
+## True if the tile has a wall stamp on the Wall TileMapLayer.
+func _is_wall(tile: Vector2i) -> bool:
+	if World.wall_layer == null:
+		return false
+	return World.wall_layer.get_cell_source_id(tile) != -1
+
+
+## True if the tile has a floor stamp on the Floor TileMapLayer.
+func _is_floor(tile: Vector2i) -> bool:
+	if World.floor_layer == null:
+		return false
+	return World.floor_layer.get_cell_source_id(tile) != -1
+
+
+## True if the tile is a completed door entity (World.doors registry).
+## Doors act as room boundaries in the BFS (walkable but block outward expansion).
+func _is_door(tile: Vector2i) -> bool:
+	for door in World.doors:
+		if door.tile == tile and door.is_completed():
+			return true
+	return false
+
+
+## Convenience: true if tile is floor OR door.  Used to seed BFS start points.
+func _is_floor_or_door(tile: Vector2i) -> bool:
+	return _is_floor(tile) or _is_door(tile)
+
+
+## Collect all tiles within `radius` Manhattan distance of `center`.
+func _tiles_in_radius(center: Vector2i, radius: int) -> Array[Vector2i]:
+	var result: Array[Vector2i] = []
+	for dx in range(-radius, radius + 1):
+		for dy in range(-radius, radius + 1):
+			var t := center + Vector2i(dx, dy)
+			if _in_bounds(t):
+				result.append(t)
+	return result
diff --git a/scenes/world/room_detector.gd.uid b/scenes/world/room_detector.gd.uid
new file mode 100644
index 0000000..2e66d6a
--- /dev/null
+++ b/scenes/world/room_detector.gd.uid
@@ -0,0 +1 @@
+uid://e16fao7xi26a
diff --git a/scenes/world/world.gd b/scenes/world/world.gd
index 1f591b6..4bdb116 100644
--- a/scenes/world/world.gd
+++ b/scenes/world/world.gd
@@ -17,6 +17,10 @@ const TILE_STONE_DARK: Vector2i = Vector2i(3, 0)
 
 const PLACEHOLDER_SOURCE_ID: int = 0
 
+const BEAUTY_SYSTEM_SCRIPT: Script = preload("res://scenes/world/beauty_system.gd")
+const DIRTINESS_SYSTEM_SCRIPT: Script = preload("res://scenes/world/dirtiness_system.gd")
+const CLEANING_PROVIDER_SCRIPT: Script = preload("res://scenes/ai/cleaning_provider.gd")
+const INDOOR_TINT_SCRIPT: Script = preload("res://scenes/world/indoor_tint_overlay.gd")
 const PAWN_SCENE: PackedScene = preload("res://scenes/pawn/pawn.tscn")
 const TREE_SCENE: PackedScene = preload("res://scenes/entities/tree.tscn")
 const ROCK_SCENE: PackedScene = preload("res://scenes/entities/rock.tscn")
@@ -86,6 +90,7 @@ const SEASON_TINTS: Dictionary = {
 @onready var eat_provider: EatProvider = $EatProvider
 @onready var sleep_provider: SleepProvider = $SleepProvider
 @onready var doctor_provider: DoctorProvider = $DoctorProvider
+@onready var room_detector = $RoomDetector  # RoomDetector — duck-typed (class_name scan-time window)
 
 
 func _ready() -> void:
@@ -112,6 +117,37 @@ func _ready() -> void:
 	World.floor_layer = floor_layer
 	World.designation_layer = designation_layer
 
+	# Phase 13 — wire RoomDetector; setup with map size so BFS knows map bounds.
+	room_detector.setup(MAP_SIZE_TILES)
+	World.room_detector = room_detector
+
+	# Phase 13 — instantiate BeautySystem + DirtinessSystem + CleaningProvider as
+	# runtime children (no .tscn entry needed; they're stateful Nodes with no
+	# editor-tunable exports). Autoload refs let entity code reach them.
+	var beauty := Node.new()
+	beauty.set_script(BEAUTY_SYSTEM_SCRIPT)
+	beauty.name = "BeautySystem"
+	add_child(beauty)
+	World.beauty_system = beauty
+
+	var dirtiness := Node.new()
+	dirtiness.set_script(DIRTINESS_SYSTEM_SCRIPT)
+	dirtiness.name = "DirtinessSystem"
+	add_child(dirtiness)
+	World.dirtiness_system = dirtiness
+
+	var cleaning := Node.new()
+	cleaning.set_script(CLEANING_PROVIDER_SCRIPT)
+	cleaning.name = "CleaningProvider"
+	add_child(cleaning)
+
+	# Phase 13 — instantiate IndoorTintOverlay so roofed rooms get a subtle warm
+	# overlay. Node2D, z_index 3 (set in its _ready). Self-listens to room_changed.
+	var indoor_tint := Node2D.new()
+	indoor_tint.set_script(INDOOR_TINT_SCRIPT)
+	indoor_tint.name = "IndoorTintOverlay"
+	add_child(indoor_tint)
+
 	# Designation: bind the paint surface + the Selection guard.
 	designation_ctl.bind(designation_layer, selection)
 
@@ -128,6 +164,7 @@ func _ready() -> void:
 	World.register_work_provider(crafting_provider)
 	World.register_work_provider(plant_provider)
 	World.register_work_provider(hauling_provider)
+	World.register_work_provider(cleaning)  # priority 2 — between haul (3) and rest (0)
 	World.register_work_provider(rest_provider)
 
 	# Phase 5: bridge designation paint events → spawn the ghost-state entity
@@ -139,6 +176,25 @@ func _ready() -> void:
 	_spawn_sample_harvestables()
 	_spawn_sample_stockpiles()
 	_seed_phase5_demo_buildings()
+	# Phase 13 — pre-stamp the cabin walls + floors on the TileMap data layers
+	# so RoomDetector can see a completed enclosure at boot without waiting for
+	# pawns to finish the build queue.  Mirrors the layout in _seed_phase5_demo_buildings.
+	_prestamp_cabin_for_room_detector()
+	_prestamp_test_shed_for_room_detector()
+	room_detector.recompute_around(Vector2i(47, 25))
+	room_detector.recompute_around(Vector2i(36, 25))  # tiny shed centroid
+
+	# Phase 13 — register existing prebuilt furniture with BeautySystem so it has
+	# a beauty score baseline at boot (the post-_complete hooks already fire for
+	# the cabin's beds/torches/workbenches, but pawns may path before the first
+	# recompute, so seed the map here).
+	for ws in World.workbenches:
+		beauty.register_furniture(ws)
+	for b in World.beds:
+		beauty.register_furniture(b)
+	for ls in World.light_sources:
+		beauty.register_furniture(ls)
+	beauty.recompute_all()
 	_run_pathfinder_spike()
 
 	# Phase 4: every 5 in-game seconds (100 ticks), re-evaluate items in
@@ -527,6 +583,88 @@ func _apply_season_tint(season: StringName) -> void:
 	Audit.log("world", "season tint → %s (%s)" % [season, tint])
 
 
+# ── Phase 13: demo seed room helper ─────────────────────────────────────────
+
+# Directly stamps the cabin perimeter walls and interior floors on the data
+# TileMap layers so RoomDetector can detect the enclosure at boot.
+# The ghost entities are already queued — this only writes the data layer
+# (same as Wall._complete / Floor._complete call).  Without this,
+# RoomDetector would have to wait until pawns finish building the walls
+# (many seconds of real time) before the first room is visible.
+#
+# Layout mirrors _seed_phase5_demo_buildings: 8×6 cabin at (44, 23),
+# door at (47, 28), 6×4 wood floor interior.
+func _prestamp_cabin_for_room_detector() -> void:
+	var origin := Vector2i(44, 23)
+	var w := 8
+	var h := 6
+	var door_x := w / 2 - 1  # 3 → tile x=47
+	var door_tile := origin + Vector2i(door_x, h - 1)
+
+	# Stamp perimeter walls (skipping the door slot).
+	for x in w:
+		World.mark_wall_tile(origin + Vector2i(x, 0), &"stone")
+		var bottom := origin + Vector2i(x, h - 1)
+		if bottom != door_tile:
+			World.mark_wall_tile(bottom, &"stone")
+	for y in range(1, h - 1):
+		World.mark_wall_tile(origin + Vector2i(0, y), &"stone")
+		World.mark_wall_tile(origin + Vector2i(w - 1, y), &"stone")
+
+	# Stamp interior floors.
+	for x in range(1, w - 1):
+		for y in range(1, h - 1):
+			World.mark_floor_tile(origin + Vector2i(x, y), &"wood")
+
+	# Stamp the door slot as a wall so the perimeter is fully closed and BFS
+	# terminates cleanly.  Door._complete() erases this wall stamp and registers
+	# the door entity; the follow-up recompute_around picks it up as a boundary.
+	World.mark_wall_tile(door_tile, &"stone")
+
+	Audit.log("world", "phase 13 demo: cabin walls+floors pre-stamped for RoomDetector")
+
+
+# Tiny 5×5 walled shed with 3×3 interior (= 9 floor tiles) — under the 16-cap
+# auto-roof threshold, so this room WILL roof. Used to exercise the indoor /
+# shelter / room-thoughts pipeline without resizing the main cabin.
+func _prestamp_test_shed_for_room_detector() -> void:
+	var origin := Vector2i(34, 23)  # left of cabin, on the grass plain
+	var w := 5
+	var h := 5
+	# Perimeter walls — instantiate complete Wall entities so they're visible.
+	for x in w:
+		_spawn_complete_wall(origin + Vector2i(x, 0))
+		_spawn_complete_wall(origin + Vector2i(x, h - 1))
+	for y in range(1, h - 1):
+		_spawn_complete_wall(origin + Vector2i(0, y))
+		_spawn_complete_wall(origin + Vector2i(w - 1, y))
+	# Interior floors — instantiate complete Floor entities.
+	for x in range(1, w - 1):
+		for y in range(1, h - 1):
+			_spawn_complete_floor(origin + Vector2i(x, y))
+
+	Audit.log("world", "phase 13 demo: 5×5 test shed pre-built (interior 9 tiles, auto-roofed)")
+
+
+# Instantiate a Wall entity in completed state at `tile`. Bypasses the build
+# queue. Used by the Phase 13 test shed seed.
+func _spawn_complete_wall(tile: Vector2i) -> void:
+	var w = WALL_SCENE.instantiate()
+	w.setup(tile, &"stone")
+	add_child(w)
+	w.build_progress = w.BUILD_TICKS
+	w.on_build_tick()  # triggers _complete() and the data-layer stamp + room recompute
+
+
+# Instantiate a Floor entity in completed state at `tile`.
+func _spawn_complete_floor(tile: Vector2i) -> void:
+	var f = FLOOR_SCENE.instantiate()
+	f.setup(tile, &"wood")
+	add_child(f)
+	f.build_progress = f.BUILD_TICKS
+	f.on_build_tick()
+
+
 # ── spike: AStarGrid2D query timing at 80² ──────────────────────────────────
 
 func _run_pathfinder_spike() -> void:
diff --git a/scenes/world/world.tscn b/scenes/world/world.tscn
index ea53d7e..e3f4e70 100644
--- a/scenes/world/world.tscn
+++ b/scenes/world/world.tscn
@@ -1,4 +1,4 @@
-[gd_scene load_steps=18 format=3 uid="uid://rimlike_world"]
+[gd_scene load_steps=19 format=3 uid="uid://rimlike_world"]
 
 [ext_resource type="Script" path="res://scenes/world/world.gd" id="1_world"]
 [ext_resource type="PackedScene" uid="uid://rimlike_camera_rig" path="res://scenes/world/camera_rig.tscn" id="2_camera"]
@@ -17,6 +17,7 @@
 [ext_resource type="Script" path="res://scenes/ai/doctor_provider.gd" id="15_doctor_provider"]
 [ext_resource type="Script" path="res://scenes/ai/wolf_spawner.gd" id="16_wolf_spawner"]
 [ext_resource type="PackedScene" uid="uid://rimlike_rain_overlay" path="res://scenes/world/rain_overlay.tscn" id="17_rain_overlay"]
+[ext_resource type="Script" path="res://scenes/world/room_detector.gd" id="18_room_detector"]
 
 [node name="World" type="Node2D"]
 y_sort_enabled = true
@@ -90,6 +91,9 @@ script = ExtResource("15_doctor_provider")
 [node name="WolfSpawner" type="Node" parent="."]
 script = ExtResource("16_wolf_spawner")
 
+[node name="RoomDetector" type="Node" parent="."]
+script = ExtResource("18_room_detector")
+
 [node name="WeatherLayer" type="CanvasLayer" parent="."]
 layer = 5