"InteriorFlooring": {
  "type": "object",
  "additionalProperties": false,
  "title": "InteriorFlooring",
  "description": "Describes the interior template parameters for all floors for this floorplan.\nAll floors not explicitly targeted will have a random floor material assigned by room type.",
  "properties": {
    "MaterialSets": {
      "type": "array",
      "minItems": 0,
      "maxItems": 6,
      "title": "Materialsets",
      "default": [],
      "items": {}
    }
  }
}

 "MaterialSets": {
  "type": "array",
  "minItems": 0,
  "maxItems": 6,
  "title": "Materialsets",
  "default": [],
  "items": {"$ref": "#/definitions/InteriorMaterialSet"}
}

 "items": {"$ref": "#/definitions/InteriorMaterialSet"}