diff --git a/designs/sample-house-design.json b/designs/sample-house-design.json
new file mode 100644
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+++ b/designs/sample-house-design.json
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+{
+  "name": "Musterhaus Einrichtung",
+  "description": "Complete furniture layout for the sample house",
+  "houseFile": "data/sample-house.json",
+  "catalogFile": "data/furniture-catalog.json",
+  "coordinateSystem": {
+    "description": "Positions are in room-local coordinates",
+    "x": "Along room width: 0 = west wall, max = east wall",
+    "z": "Along room length: 0 = south wall, max = north wall",
+    "rotation": "Degrees around Y axis. 0 = front faces north, 90 = east, 180 = south, 270 = west"
+  },
+  "rooms": [
+    {
+      "roomId": "eg-flur",
+      "name": "Flur (Hallway)",
+      "dimensions": { "width": 2.0, "length": 9.0 },
+      "furniture": [
+        {
+          "catalogId": "shoe-cabinet",
+          "position": { "x": 1.825, "z": 1.9 },
+          "rotation": 270,
+          "note": "Against east wall, between guest WC and office doors"
+        },
+        {
+          "catalogId": "coat-rack",
+          "position": { "x": 1.85, "z": 7.0 },
+          "rotation": 270,
+          "note": "Against east wall, north section"
+        },
+        {
+          "catalogId": "console-table",
+          "position": { "x": 0.15, "z": 3.0 },
+          "rotation": 90,
+          "note": "Against west wall, between kitchen and living room doors"
+        },
+        {
+          "catalogId": "mirror-hall",
+          "position": { "x": 0.02, "z": 3.0 },
+          "rotation": 90,
+          "wallMounted": true,
+          "note": "On west wall above console table"
+        },
+        {
+          "catalogId": "rug-small",
+          "position": { "x": 1.0, "z": 1.0 },
+          "rotation": 0,
+          "note": "Entry area rug"
+        }
+      ]
+    },
+    {
+      "roomId": "eg-wohnzimmer",
+      "name": "Wohnzimmer (Living Room)",
+      "dimensions": { "width": 4.5, "length": 5.5 },
+      "furniture": [
+        {
+          "catalogId": "tv-stand",
+          "position": { "x": 2.25, "z": 0.225 },
+          "rotation": 0,
+          "note": "Against south wall, centered"
+        },
+        {
+          "catalogId": "tv",
+          "position": { "x": 2.25, "z": 0.225 },
+          "rotation": 0,
+          "note": "On TV stand"
+        },
+        {
+          "catalogId": "sofa-3seat",
+          "position": { "x": 2.25, "z": 3.0 },
+          "rotation": 180,
+          "note": "Facing south toward TV"
+        },
+        {
+          "catalogId": "coffee-table",
+          "position": { "x": 2.25, "z": 1.8 },
+          "rotation": 0,
+          "note": "Between sofa and TV"
+        },
+        {
+          "catalogId": "armchair",
+          "position": { "x": 0.6, "z": 1.5 },
+          "rotation": 90,
+          "note": "Side seating, facing east toward coffee table"
+        },
+        {
+          "catalogId": "bookshelf",
+          "position": { "x": 0.15, "z": 2.6 },
+          "rotation": 90,
+          "note": "Against west wall between windows"
+        },
+        {
+          "catalogId": "rug-large",
+          "position": { "x": 2.25, "z": 2.0 },
+          "rotation": 0,
+          "note": "Under seating area"
+        },
+        {
+          "catalogId": "floor-lamp",
+          "position": { "x": 3.8, "z": 3.3 },
+          "rotation": 0,
+          "note": "Next to sofa, right side"
+        },
+        {
+          "catalogId": "plant-large",
+          "position": { "x": 0.3, "z": 5.2 },
+          "rotation": 0,
+          "note": "Northwest corner"
+        }
+      ]
+    },
+    {
+      "roomId": "eg-kueche",
+      "name": "Kueche (Kitchen)",
+      "dimensions": { "width": 4.0, "length": 3.5 },
+      "furniture": [
+        {
+          "catalogId": "kitchen-counter",
+          "position": { "x": 1.2, "z": 0.3 },
+          "rotation": 0,
+          "note": "Along south wall under window"
+        },
+        {
+          "catalogId": "kitchen-wall-cabinet",
+          "position": { "x": 1.2, "z": 0.175 },
+          "rotation": 0,
+          "wallMounted": true,
+          "note": "Above counter on south wall"
+        },
+        {
+          "catalogId": "fridge",
+          "position": { "x": 0.325, "z": 3.175 },
+          "rotation": 90,
+          "note": "Against west wall, north end, clear of window"
+        },
+        {
+          "catalogId": "kitchen-island",
+          "position": { "x": 2.0, "z": 2.0 },
+          "rotation": 0,
+          "note": "Center of kitchen, workspace and casual seating"
+        }
+      ]
+    },
+    {
+      "roomId": "eg-esszimmer",
+      "name": "Esszimmer (Dining Room)",
+      "dimensions": { "width": 4.5, "length": 4.0 },
+      "furniture": [
+        {
+          "catalogId": "dining-table",
+          "position": { "x": 2.25, "z": 2.0 },
+          "rotation": 0,
+          "note": "Centered in room"
+        },
+        {
+          "catalogId": "dining-chair",
+          "instanceId": "dining-chair-n1",
+          "position": { "x": 1.65, "z": 2.75 },
+          "rotation": 180,
+          "note": "North side of table, left"
+        },
+        {
+          "catalogId": "dining-chair",
+          "instanceId": "dining-chair-n2",
+          "position": { "x": 2.85, "z": 2.75 },
+          "rotation": 180,
+          "note": "North side of table, right"
+        },
+        {
+          "catalogId": "dining-chair",
+          "instanceId": "dining-chair-s1",
+          "position": { "x": 1.65, "z": 1.25 },
+          "rotation": 0,
+          "note": "South side of table, left"
+        },
+        {
+          "catalogId": "dining-chair",
+          "instanceId": "dining-chair-s2",
+          "position": { "x": 2.85, "z": 1.25 },
+          "rotation": 0,
+          "note": "South side of table, right"
+        },
+        {
+          "catalogId": "dining-chair",
+          "instanceId": "dining-chair-w",
+          "position": { "x": 1.0, "z": 2.0 },
+          "rotation": 90,
+          "note": "West end of table"
+        },
+        {
+          "catalogId": "dining-chair",
+          "instanceId": "dining-chair-e",
+          "position": { "x": 3.5, "z": 2.0 },
+          "rotation": 270,
+          "note": "East end of table"
+        },
+        {
+          "catalogId": "sideboard",
+          "position": { "x": 0.2, "z": 2.5 },
+          "rotation": 90,
+          "note": "Against west wall"
+        }
+      ]
+    },
+    {
+      "roomId": "eg-arbeitszimmer",
+      "name": "Arbeitszimmer (Home Office)",
+      "dimensions": { "width": 5.5, "length": 3.5 },
+      "furniture": [
+        {
+          "catalogId": "desk",
+          "position": { "x": 2.7, "z": 0.35 },
+          "rotation": 180,
+          "note": "Against south wall facing window"
+        },
+        {
+          "catalogId": "office-chair",
+          "position": { "x": 2.7, "z": 1.1 },
+          "rotation": 180,
+          "note": "At desk, facing south"
+        },
+        {
+          "catalogId": "bookshelf",
+          "position": { "x": 4.5, "z": 3.35 },
+          "rotation": 180,
+          "note": "Against north wall, east side"
+        },
+        {
+          "catalogId": "sofa-2seat",
+          "position": { "x": 1.5, "z": 3.075 },
+          "rotation": 180,
+          "note": "Against north wall for guests"
+        },
+        {
+          "catalogId": "floor-lamp",
+          "position": { "x": 0.3, "z": 2.8 },
+          "rotation": 0,
+          "note": "Next to sofa"
+        },
+        {
+          "catalogId": "plant-large",
+          "position": { "x": 5.2, "z": 3.2 },
+          "rotation": 0,
+          "note": "Northeast corner"
+        },
+        {
+          "catalogId": "desk-lamp",
+          "position": { "x": 3.2, "z": 0.35 },
+          "rotation": 0,
+          "note": "On desk, right side"
+        }
+      ]
+    },
+    {
+      "roomId": "eg-gaeste-wc",
+      "name": "Gaeste-WC (Guest WC)",
+      "dimensions": { "width": 2.5, "length": 1.5 },
+      "furniture": [
+        {
+          "catalogId": "toilet",
+          "position": { "x": 2.175, "z": 0.75 },
+          "rotation": 270,
+          "note": "Against east wall, facing west"
+        },
+        {
+          "catalogId": "sink-bathroom",
+          "position": { "x": 1.2, "z": 1.275 },
+          "rotation": 180,
+          "note": "Against north wall"
+        }
+      ]
+    },
+    {
+      "roomId": "eg-hwr",
+      "name": "Hauswirtschaftsraum (Utility Room)",
+      "dimensions": { "width": 3.0, "length": 1.5 },
+      "furniture": [
+        {
+          "catalogId": "washing-machine",
+          "position": { "x": 2.0, "z": 0.3 },
+          "rotation": 0,
+          "note": "Against south wall"
+        }
+      ]
+    },
+    {
+      "roomId": "og-flur",
+      "name": "Flur OG (Upper Hallway)",
+      "dimensions": { "width": 2.0, "length": 6.0 },
+      "furniture": [
+        {
+          "catalogId": "rug-small",
+          "position": { "x": 1.0, "z": 3.0 },
+          "rotation": 0,
+          "note": "Center of hallway"
+        }
+      ]
+    },
+    {
+      "roomId": "og-schlafzimmer",
+      "name": "Schlafzimmer (Master Bedroom)",
+      "dimensions": { "width": 4.5, "length": 5.0 },
+      "furniture": [
+        {
+          "catalogId": "double-bed",
+          "position": { "x": 2.8, "z": 1.15 },
+          "rotation": 0,
+          "note": "Headboard against south wall, offset right to clear en-suite door"
+        },
+        {
+          "catalogId": "nightstand",
+          "instanceId": "nightstand-left",
+          "position": { "x": 1.675, "z": 0.4 },
+          "rotation": 0,
+          "note": "Left side of bed"
+        },
+        {
+          "catalogId": "nightstand",
+          "instanceId": "nightstand-right",
+          "position": { "x": 3.925, "z": 0.4 },
+          "rotation": 0,
+          "note": "Right side of bed"
+        },
+        {
+          "catalogId": "wardrobe",
+          "position": { "x": 4.2, "z": 2.5 },
+          "rotation": 270,
+          "note": "Against east wall, between bed area and door"
+        },
+        {
+          "catalogId": "rug-large",
+          "position": { "x": 2.8, "z": 2.5 },
+          "rotation": 0,
+          "note": "Beside and partially under bed"
+        },
+        {
+          "catalogId": "floor-lamp",
+          "position": { "x": 1.2, "z": 0.3 },
+          "rotation": 0,
+          "note": "Near left nightstand"
+        }
+      ]
+    },
+    {
+      "roomId": "og-elternbad",
+      "name": "Elternbad (En-suite Bathroom)",
+      "dimensions": { "width": 2.5, "length": 3.0 },
+      "furniture": [
+        {
+          "catalogId": "shower",
+          "position": { "x": 2.05, "z": 0.45 },
+          "rotation": 0,
+          "note": "Southeast corner"
+        },
+        {
+          "catalogId": "toilet",
+          "position": { "x": 0.8, "z": 0.325 },
+          "rotation": 0,
+          "note": "Against south wall, west side"
+        },
+        {
+          "catalogId": "sink-bathroom",
+          "position": { "x": 2.275, "z": 2.0 },
+          "rotation": 270,
+          "note": "Against east wall, central"
+        },
+        {
+          "catalogId": "bathroom-cabinet",
+          "position": { "x": 2.4, "z": 2.0 },
+          "rotation": 270,
+          "wallMounted": true,
+          "note": "Above sink on east wall"
+        }
+      ]
+    },
+    {
+      "roomId": "og-kinderzimmer1",
+      "name": "Kinderzimmer 1 (Child's Room 1)",
+      "dimensions": { "width": 4.5, "length": 4.0 },
+      "furniture": [
+        {
+          "catalogId": "single-bed",
+          "position": { "x": 0.8, "z": 3.0 },
+          "rotation": 180,
+          "note": "Headboard against north wall, west side"
+        },
+        {
+          "catalogId": "nightstand",
+          "position": { "x": 1.55, "z": 3.7 },
+          "rotation": 0,
+          "note": "Right side of bed, near north wall"
+        },
+        {
+          "catalogId": "desk",
+          "position": { "x": 2.1, "z": 0.35 },
+          "rotation": 180,
+          "note": "Against south wall facing window"
+        },
+        {
+          "catalogId": "desk-lamp",
+          "position": { "x": 2.6, "z": 0.35 },
+          "rotation": 0,
+          "note": "On desk"
+        },
+        {
+          "catalogId": "kids-wardrobe",
+          "position": { "x": 4.225, "z": 2.5 },
+          "rotation": 270,
+          "note": "Against east wall, north of door"
+        },
+        {
+          "catalogId": "kids-shelf",
+          "position": { "x": 3.5, "z": 3.85 },
+          "rotation": 180,
+          "note": "Against north wall"
+        },
+        {
+          "catalogId": "rug-small",
+          "position": { "x": 2.25, "z": 2.0 },
+          "rotation": 0,
+          "note": "Center play area"
+        }
+      ]
+    },
+    {
+      "roomId": "og-kinderzimmer2",
+      "name": "Kinderzimmer 2 (Child's Room 2)",
+      "dimensions": { "width": 4.5, "length": 3.5 },
+      "furniture": [
+        {
+          "catalogId": "single-bed",
+          "position": { "x": 3.5, "z": 2.5 },
+          "rotation": 180,
+          "note": "Headboard against north wall, east side"
+        },
+        {
+          "catalogId": "nightstand",
+          "position": { "x": 2.775, "z": 3.3 },
+          "rotation": 0,
+          "note": "Left side of bed"
+        },
+        {
+          "catalogId": "desk",
+          "position": { "x": 1.5, "z": 0.35 },
+          "rotation": 180,
+          "note": "Against south wall facing window"
+        },
+        {
+          "catalogId": "desk-lamp",
+          "position": { "x": 1.0, "z": 0.35 },
+          "rotation": 0,
+          "note": "On desk"
+        },
+        {
+          "catalogId": "kids-wardrobe",
+          "position": { "x": 1.0, "z": 3.225 },
+          "rotation": 180,
+          "note": "Against north wall, west side"
+        },
+        {
+          "catalogId": "kids-shelf",
+          "position": { "x": 0.15, "z": 2.0 },
+          "rotation": 90,
+          "note": "Against west wall, south of door"
+        },
+        {
+          "catalogId": "rug-small",
+          "position": { "x": 2.25, "z": 1.75 },
+          "rotation": 0,
+          "note": "Center play area"
+        }
+      ]
+    },
+    {
+      "roomId": "og-badezimmer",
+      "name": "Badezimmer (Main Bathroom)",
+      "dimensions": { "width": 3.5, "length": 3.0 },
+      "furniture": [
+        {
+          "catalogId": "bathtub",
+          "position": { "x": 1.5, "z": 0.375 },
+          "rotation": 90,
+          "note": "Along south wall, long side parallel to wall"
+        },
+        {
+          "catalogId": "sink-bathroom",
+          "position": { "x": 1.5, "z": 2.775 },
+          "rotation": 180,
+          "note": "Against north wall"
+        },
+        {
+          "catalogId": "bathroom-cabinet",
+          "position": { "x": 1.5, "z": 2.9 },
+          "rotation": 180,
+          "wallMounted": true,
+          "note": "Above sink on north wall"
+        },
+        {
+          "catalogId": "toilet",
+          "position": { "x": 3.175, "z": 2.5 },
+          "rotation": 270,
+          "note": "Against east wall, near window"
+        },
+        {
+          "catalogId": "washing-machine",
+          "position": { "x": 3.2, "z": 0.3 },
+          "rotation": 0,
+          "note": "Against south wall, east side"
+        }
+      ]
+    },
+    {
+      "roomId": "og-gaestezimmer",
+      "name": "Gaestezimmer (Guest Room)",
+      "dimensions": { "width": 5.5, "length": 3.0 },
+      "furniture": [
+        {
+          "catalogId": "single-bed",
+          "position": { "x": 1.0, "z": 1.5 },
+          "rotation": 270,
+          "note": "Against west wall, headboard west, centered vertically"
+        },
+        {
+          "catalogId": "nightstand",
+          "position": { "x": 1.7, "z": 2.7 },
+          "rotation": 0,
+          "note": "North side of bed"
+        },
+        {
+          "catalogId": "wardrobe",
+          "position": { "x": 4.0, "z": 0.3 },
+          "rotation": 0,
+          "note": "Against south wall, east portion"
+        },
+        {
+          "catalogId": "desk",
+          "position": { "x": 4.5, "z": 2.65 },
+          "rotation": 180,
+          "note": "Against north wall near east window"
+        },
+        {
+          "catalogId": "desk-lamp",
+          "position": { "x": 4.0, "z": 2.65 },
+          "rotation": 0,
+          "note": "On desk"
+        }
+      ]
+    }
+  ]
+}