{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://plattegrond.crocode.nl/wallgraph.schema.json",
  "title": "Wallgraph plan document",
  "description": "A floorplan as a planar graph of wall centerlines. Every stored coordinate and length is an integer number of millimetres, and y points down, matching the canvas. Nothing derived is stored: wall faces, mitred corners, room polygons and areas are all recomputed from this graph when the plan is drawn.",
  "type": "object",
  "required": [
    "version",
    "unit",
    "gridMm",
    "floors"
  ],
  "additionalProperties": false,
  "properties": {
    "version": {
      "const": 1,
      "description": "Document format version. Only 1 exists."
    },
    "unit": {
      "const": "mm",
      "description": "Stored unit. Always millimetres."
    },
    "gridMm": {
      "type": "integer",
      "minimum": 1,
      "description": "Grid spacing in mm. 100 by default."
    },
    "areaMode": {
      "enum": [
        "net",
        "centerline",
        "bvo"
      ],
      "description": "Which convention reported room areas use. 'net' is inner wall faces (NEN 2580) and is the default when absent; 'centerline' is hart-op-hart; 'bvo' is the gross area, measured to the outer face of the facade where a bounding wall has one and to the centreline where it does not, which is what NEN 2580 says about a party wall. On a plan whose walls carry no facadeMm, 'bvo' equals 'centerline'."
    },
    "dimMode": {
      "enum": [
        "centerline",
        "clear",
        "both"
      ],
      "description": "Which convention the drawn dimensions use. 'centerline' is hart-op-hart and is the default when absent; 'clear' measures face to face (dagmaat); 'both' draws each as its own chain."
    },
    "mountMarks": {
      "type": "boolean",
      "description": "Write each device's mounting height beside it, in mm above the finished floor. Absent means off: a plattegrond is not an installatietekening until the drawing says so. The figure itself is derived -- a symbol's own height if it states one, otherwise the conventional height for its type."
    },
    "project": {
      "type": "object",
      "additionalProperties": false,
      "description": "Title-block data for the permit sheet export. All fields are authored and optional; absent fields render as empty cells.",
      "properties": {
        "name": {
          "type": "string",
          "description": "Project name as the title block states it."
        },
        "address": {
          "type": "string",
          "description": "Site address."
        },
        "number": {
          "type": "string",
          "description": "Drawing number (tekeningnummer)."
        },
        "author": {
          "type": "string",
          "description": "Who drew it (getekend)."
        },
        "date": {
          "type": "string",
          "description": "Date as written on the sheet. Absent means the export date."
        }
      }
    },
    "northDeg": {
      "type": "integer",
      "minimum": 0,
      "maximum": 359,
      "description": "Where north points: degrees clockwise from screen-up. Absent means the direction has not been stated and no north arrow is drawn."
    },
    "guid": {
      "type": "string",
      "pattern": "^[0-9a-f]{32}$",
      "description": "Per-document seed for IFC GlobalIds: combined with each element's own id, it keeps identities stable across re-exports and keeps two documents from colliding. Absent on documents written before this existed."
    },
    "groundMm": {
      "type": "integer",
      "description": "Elevation of the ground floor (floors[0]) above project zero (Peil), mm. May be negative. Absent means 0."
    },
    "continuations": {
      "type": "array",
      "items": {
        "$ref": "#/$defs/routeContinuation"
      },
      "description": "Vertical service links between route endpoints on different storeys. Absent means the plan has no cross-floor service continuity."
    },
    "floors": {
      "type": "array",
      "minItems": 1,
      "items": {
        "$ref": "#/$defs/floor"
      },
      "description": "Storeys, lowest first. The floor below draws as a tracing underlay."
    }
  },
  "$defs": {
    "id": {
      "type": "string",
      "minLength": 1,
      "description": "Unique within the document."
    },
    "fireRating": {
      "type": "object",
      "required": [
        "kind",
        "minutes"
      ],
      "additionalProperties": false,
      "description": "A Dutch fire-resistance rating.",
      "properties": {
        "kind": {
          "enum": [
            "wbdbo",
            "wbd",
            "wrd"
          ],
          "description": "wbdbo: weerstand tegen branddoorslag en brandoverslag, the Bouwbesluit figure for a door in a compartment wall. wbd: branddoorslag alone. wrd: weerstand tegen rookdoorgang."
        },
        "minutes": {
          "type": "integer",
          "minimum": 0
        }
      }
    },
    "floor": {
      "type": "object",
      "required": [
        "id",
        "name",
        "nodes",
        "walls",
        "symbols"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "name": {
          "type": "string"
        },
        "nodes": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/node"
          }
        },
        "walls": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/wall"
          }
        },
        "symbols": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/symbol"
          }
        },
        "height": {
          "type": "integer",
          "minimum": 1,
          "description": "Storey height in mm, floor to floor. Stairs on this floor climb it unless they state a rise of their own. Absent means 2800."
        },
        "ceilingMm": {
          "type": "integer",
          "minimum": 1,
          "description": "Finished ceiling height in mm above this storey's floor, where a suspended ceiling has been dropped under the slab. A finish and nothing else: it changes no stair, no space and no area, only the wall FACE area reported by core/surface.ts. A figure at or above the storey height states nothing and is ignored. Absent means none, so a face is finished floor to floor."
        },
        "stairs": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/stair"
          },
          "description": "Placed stairs. Absent means the storey has none."
        },
        "vides": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/vide"
          },
          "description": "Openings in this floor's slab. Absent means the storey has none."
        },
        "structure": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/structural"
          },
          "description": "Load-bearing and guarding elements that are not walls: columns, beams and railings, each a placed object with its own figures. None enters the wall graph. Absent means the storey has none."
        },
        "furnishings": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/furnishing"
          },
          "description": "What the storey is fitted out with: cabinetry, appliances, sanitary fixtures and furniture. Absent means the storey has none."
        },
        "routes": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/route"
          },
          "description": "Manually drawn service runs -- electrical, water, ventilation -- as switchable layers over the plan. Absent means the storey has none."
        },
        "roomNames": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/roomName"
          },
          "description": "What the rooms are called. Rooms themselves are derived from the wall graph, so only the name and the point it was written at are stored."
        },
        "underlay": {
          "$ref": "#/$defs/underlay",
          "description": "A trace-over image for this floor. Absent means none loaded. Stripped from every floor before a document is encoded into a share-link URL fragment (see io/link.ts's encodePlan) -- a share link carries the drawing, not the scan. JSON export/import keeps it verbatim."
        }
      }
    },
    "node": {
      "type": "object",
      "description": "A junction. Walls meet here; corners are derived from the meeting.",
      "required": [
        "id",
        "x",
        "y"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "x": {
          "type": "integer",
          "description": "mm, positive to the right."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive DOWN — world space matches the canvas."
        }
      }
    },
    "wall": {
      "type": "object",
      "description": "A centerline edge between two nodes, with a thickness.",
      "required": [
        "id",
        "a",
        "b",
        "thickness",
        "bulge",
        "openings"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "a": {
          "$ref": "#/$defs/id",
          "description": "Start node id."
        },
        "b": {
          "$ref": "#/$defs/id",
          "description": "End node id."
        },
        "thickness": {
          "type": "integer",
          "minimum": 1,
          "description": "mm. 100 interior, 300 exterior by default."
        },
        "bulge": {
          "type": "number",
          "description": "DXF bulge, tan(theta/4): 0 is straight, positive bows toward perp(a->b), which under y-down is the clockwise visual side. Required — omitting it does not mean straight, it means the arc maths sees NaN."
        },
        "openings": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/opening"
          }
        },
        "height": {
          "type": "integer",
          "minimum": 1,
          "description": "mm, floor to floor. Absent means the storey height."
        },
        "loadBearing": {
          "type": "boolean",
          "description": "Authored and tri-state: absent means not stated, distinct from false."
        },
        "fireRating": {
          "$ref": "#/$defs/fireRating",
          "description": "A fire compartment wall's rating."
        },
        "material": {
          "enum": [
            "masonry",
            "concrete",
            "timber",
            "steel",
            "glass",
            "sandwich"
          ],
          "description": "What the body is built of; a single material, not a build-up. Absent means not stated, distinct from \"masonry\". \"glass\" and \"sandwich\" are infill and change the drawing: the body is drawn as a light band between its two faces rather than as poche. The rest draw as poche and carry the name to IFC."
        },
        "postMm": {
          "type": "integer",
          "minimum": 1,
          "description": "Post (stijl) centres, mm — the frame the body is carried on, whether those members are the mullions of a curtain wall, the columns of a steel portal frame or the studs of a timber wall. Read as a MAXIMUM bay width: each run between openings is divided into equal bays no wider than this, so a door pushes the posts of its run aside instead of one landing in the doorway. Absent means no frame is drawn."
        },
        "postWidthMm": {
          "type": "integer",
          "minimum": 1,
          "description": "A post's own width along the wall, mm; its depth is the wall thickness. Absent means the centres are stated and the section is not, and the post is drawn as a line. Ignored without postMm, and never drawn wider than its bay."
        },
        "facadeMm": {
          "type": "integer",
          "minimum": 1,
          "description": "Cladding outside the structural body, mm. `thickness` stays the STRUCTURE: a sandwich wall built 100 + 100 is thickness 100 with facadeMm 100. A skin, not a build-up — it lies wholly outside the structural faces, so it changes neither the wall graph, room detection nor the net area. It does set the gross area, which is measured to its outer face (see areaMode \"bvo\"). Absent means none."
        },
        "facadeSide": {
          "enum": [
            "left",
            "right"
          ],
          "description": "Which side of the wall's own a->b direction the facade is on; \"left\" is +perp(tangent), the clockwise visual side. Absent means \"left\". Stored rather than derived from which side the rooms are on, because that probe flips as soon as a wall is redrawn."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour; absent means the plan's default masonry ink. States the status of the work the way a verbouwtekening does, and takes the fill, not just the outline."
        }
      }
    },
    "opening": {
      "type": "object",
      "description": "A hole in one wall, parameterised along it. Openings are never nodes in the graph: moving the wall moves its doors, and the hole is carved when drawn.",
      "required": [
        "id",
        "kind",
        "t",
        "width",
        "sashes"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "kind": {
          "enum": [
            "door",
            "window",
            "passage"
          ]
        },
        "t": {
          "type": "integer",
          "description": "Centre of the opening, measured from node a along the centerline, mm."
        },
        "width": {
          "type": "integer",
          "minimum": 1,
          "description": "mm across the wall opening."
        },
        "sashes": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/sash"
          },
          "description": "Panes across the opening in a->b order. Empty for a passage."
        },
        "glazed": {
          "type": "boolean",
          "description": "Glazed leaf — drawn as a thin double line."
        },
        "powered": {
          "type": "boolean",
          "description": "Electrically operated."
        },
        "selfClosing": {
          "type": "boolean",
          "description": "Self-closing, as a fire door must be."
        },
        "fireRating": {
          "$ref": "#/$defs/fireRating",
          "description": "A double door has one rating, not two."
        },
        "sillHeight": {
          "type": "integer",
          "description": "mm above the floor. Only meaningful for a window; absent means 900 (borstwering) for a window, 0 for a door or passage."
        },
        "height": {
          "type": "integer",
          "description": "mm. Absent means the kind's default: 2315 for a door or passage (binnendeurkozijn dagmaat), 1415 for a window."
        }
      }
    },
    "sash": {
      "type": "object",
      "description": "One movable (or fixed) pane within an opening.",
      "required": [
        "action"
      ],
      "additionalProperties": false,
      "properties": {
        "width": {
          "type": "integer",
          "minimum": 0,
          "description": "mm. Omit to share what is left equally."
        },
        "action": {
          "enum": [
            "fixed",
            "turn",
            "tilt",
            "turn-tilt",
            "pivot",
            "tumble",
            "project",
            "parallel",
            "double-acting",
            "overhead",
            "slide",
            "slide-vertical",
            "turn-slide",
            "fold",
            "revolve"
          ]
        },
        "hinge": {
          "enum": [
            "a",
            "b",
            "head",
            "sill"
          ],
          "description": "'a'/'b' are the jambs; 'head'/'sill' are horizontal and invisible in plan."
        },
        "outward": {
          "type": "boolean",
          "description": "true = naar buiten draaiend, drawn solid; absent = inward, dashed."
        },
        "slideTo": {
          "enum": [
            "a",
            "b"
          ]
        },
        "spin": {
          "enum": [
            "cw",
            "ccw"
          ],
          "description": "Revolving doors only."
        },
        "bars": {
          "type": "integer",
          "minimum": 0,
          "description": "Roedeverdeling: panes per sash. 0 or absent = undivided."
        }
      }
    },
    "vide": {
      "type": "object",
      "description": "A vide: an opening in the floor slab, open to the storey below. It is a feature of this floor rather than a storey of its own -- the slab has a hole, and the plan of this storey is where it is drawn. A trapgat is the same object. The anchor (x, y) is the centre of the opening.",
      "required": [
        "id",
        "x",
        "y",
        "rotation",
        "width",
        "depth"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        },
        "rotation": {
          "type": "number",
          "description": "Radians, clockwise on screen."
        },
        "width": {
          "type": "integer",
          "minimum": 200,
          "description": "mm."
        },
        "depth": {
          "type": "integer",
          "minimum": 200,
          "description": "mm."
        },
        "label": {
          "type": "string",
          "description": "What the opening is called on the drawing. Absent means the plain word."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour; absent means the plan's default ink."
        }
      }
    },
    "structural": {
      "description": "One structural element, told apart by `kind`. The section plane separates the three on the drawing: a column is cut by it and hatched, a beam runs above it and is dashed, a railing stands below it and is outlined.",
      "oneOf": [
        {
          "$ref": "#/$defs/column"
        },
        {
          "$ref": "#/$defs/beam"
        },
        {
          "$ref": "#/$defs/railing"
        }
      ]
    },
    "column": {
      "type": "object",
      "description": "A column: a section standing on this storey's floor. The anchor (x, y) is the centre of the section. `width` runs along the column's local x and `depth` along local y; for an H-section that is the flange breadth and the profile height, the way a steel table lists b and h. A round column reads `width` as its diameter.",
      "required": [
        "id",
        "kind",
        "x",
        "y",
        "rotation",
        "shape",
        "width",
        "depth"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "kind": {
          "const": "column"
        },
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        },
        "rotation": {
          "type": "number",
          "description": "Radians, clockwise on screen."
        },
        "shape": {
          "enum": [
            "rect",
            "round",
            "h"
          ]
        },
        "width": {
          "type": "integer",
          "minimum": 50,
          "maximum": 2000,
          "description": "mm."
        },
        "depth": {
          "type": "integer",
          "minimum": 50,
          "maximum": 2000,
          "description": "mm."
        },
        "height": {
          "type": "integer",
          "minimum": 50,
          "maximum": 20000,
          "description": "Where the column stops, mm above this storey's floor. Absent means the storey height: the column carries the floor above. A column under a vide's edge beam states its own. At or below 1200 it is not cut by the section plane and is drawn in outline."
        },
        "label": {
          "type": "string",
          "description": "Designation written on the drawing. Absent means none."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour; absent means the plan's default ink."
        },
        "material": {
          "enum": [
            "masonry",
            "concrete",
            "timber",
            "steel",
            "glass",
            "sandwich"
          ],
          "description": "Absent means not stated."
        }
      }
    },
    "beam": {
      "type": "object",
      "description": "A beam between two free points. The endpoints are coordinates of its own rather than graph nodes: a beam spans between whatever supports it, and moving a wall does not move a beam resting on it. Drawn dashed: it runs above the section plane.",
      "required": [
        "id",
        "kind",
        "a",
        "b",
        "width",
        "depth"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "kind": {
          "const": "beam"
        },
        "a": {
          "$ref": "#/$defs/point"
        },
        "b": {
          "$ref": "#/$defs/point"
        },
        "width": {
          "type": "integer",
          "minimum": 50,
          "maximum": 2000,
          "description": "Breadth in plan, mm: a steel section's flange width."
        },
        "depth": {
          "type": "integer",
          "minimum": 50,
          "maximum": 2000,
          "description": "Section height, mm, vertical."
        },
        "bottomMm": {
          "type": "integer",
          "minimum": 0,
          "maximum": 20000,
          "description": "Underside above this storey's floor, mm. Absent means the beam carries the floor above: its top is at the storey height."
        },
        "label": {
          "type": "string",
          "description": "Designation written on the drawing, e.g. \"HEA 200\". Absent means none."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour; absent means the plan's default ink."
        },
        "material": {
          "enum": [
            "masonry",
            "concrete",
            "timber",
            "steel",
            "glass",
            "sandwich"
          ],
          "description": "Absent means not stated."
        }
      }
    },
    "railing": {
      "type": "object",
      "description": "A railing along a free edge: a vide, a landing, a stair. Drawn in outline: it stands below the section plane.",
      "required": [
        "id",
        "kind",
        "a",
        "b",
        "width",
        "height",
        "postMm"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "kind": {
          "const": "railing"
        },
        "a": {
          "$ref": "#/$defs/point"
        },
        "b": {
          "$ref": "#/$defs/point"
        },
        "width": {
          "type": "integer",
          "minimum": 10,
          "maximum": 300,
          "description": "Breadth in plan, mm: the handrail."
        },
        "height": {
          "type": "integer",
          "minimum": 100,
          "maximum": 3000,
          "description": "Height above the floor, mm."
        },
        "postMm": {
          "type": "integer",
          "minimum": 0,
          "maximum": 5000,
          "description": "Post centres along the run, mm. 0 means no posts drawn."
        },
        "label": {
          "type": "string",
          "description": "Designation written on the drawing. Absent means none."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour; absent means the plan's default ink."
        },
        "material": {
          "enum": [
            "masonry",
            "concrete",
            "timber",
            "steel",
            "glass",
            "sandwich"
          ],
          "description": "Absent means not stated."
        }
      }
    },
    "point": {
      "type": "object",
      "description": "A world point in integer mm, y positive down.",
      "required": [
        "x",
        "y"
      ],
      "additionalProperties": false,
      "properties": {
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        }
      }
    },
    "route": {
      "type": "object",
      "description": "An authored building-service network -- electrical, water, ventilation or gas -- as a switchable layer over the plan. Explicit point and segment ids form a graph, so shared trunks are stored once and may branch. Segments use the same DXF bulge convention as a wall's centerline.",
      "required": [
        "id",
        "discipline",
        "points",
        "segments"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "discipline": {
          "enum": [
            "electrical",
            "water",
            "heating",
            "vent",
            "gas"
          ]
        },
        "points": {
          "type": "array",
          "minItems": 1,
          "items": {
            "$ref": "#/$defs/routePoint"
          },
          "description": "The network nodes. A single point is a cross-floor starter awaiting a local segment."
        },
        "segments": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/routeSegment"
          },
          "description": "Explicit graph edges. Shared trunks occur once and branch at point ids."
        },
        "tag": {
          "type": "string",
          "description": "Short identifier printed on the plan."
        },
        "name": {
          "type": "string",
          "description": "Descriptive route/network name."
        },
        "board": {
          "type": "string",
          "description": "Electrical distribution board identifier."
        },
        "installation": {
          "enum": [
            "concealed",
            "surface",
            "floor",
            "ceiling",
            "free"
          ]
        },
        "height": {
          "type": "integer",
          "minimum": 0,
          "description": "Height above finished floor, mm."
        },
        "kind": {
          "enum": [
            "power",
            "utp",
            "coax"
          ],
          "description": "Electrical-only: what the run carries. Meaningful only when discipline is \"electrical\"; a water or vent route ignores it. Absent means \"power\", the ordinary case."
        },
        "veins": {
          "type": "integer",
          "minimum": 2,
          "maximum": 8,
          "description": "Aantal aders. Meaningful for power runs only (kind is \"power\" or absent) -- a data run's pairs follow from `spec` instead. Absent means 3, the ordinary geschakelde/wandcontactdoos run."
        },
        "group": {
          "type": "string",
          "description": "Groep, as the meterkast labels it (\"1\", \"2\", \"K1\"). Meaningful for power runs; a data run does not belong to a groep."
        },
        "spec": {
          "type": "string",
          "description": "Data-cable spec (\"Cat6\"). Meaningful for kind \"utp\" or \"coax\"."
        },
        "water": {
          "enum": [
            "koud",
            "warm",
            "afvoer"
          ],
          "description": "Water-only: koud/warm/afvoer. Meaningful only when discipline is \"water\"; an electrical or vent route ignores it. Absent means \"koud\", the ordinary supply run."
        },
        "diameter": {
          "type": "integer",
          "minimum": 8,
          "maximum": 200,
          "description": "Water, heating or gas nominal pipe diameter, mm. Water defaults per kind -- 15 for koud/warm, 50 for afvoer; heating defaults to 16; gas to 15."
        },
        "heat": {
          "enum": [
            "aanvoer",
            "retour"
          ],
          "description": "Heating-only: which leg of the CV circuit. Meaningful only when discipline is \"heating\". Absent means \"aanvoer\", the flow leg."
        },
        "vent": {
          "enum": [
            "toevoer",
            "afvoer"
          ],
          "description": "Vent-only: toevoer/afvoer. Meaningful only when discipline is \"vent\"; an electrical or water route ignores it. Absent means \"toevoer\" (supply air)."
        },
        "ductDiameter": {
          "type": "integer",
          "minimum": 63,
          "maximum": 400,
          "description": "Vent-only: nominal duct diameter, mm. Meaningful only when discipline is \"vent\". Absent means 125."
        },
        "flow": {
          "type": "integer",
          "minimum": 1,
          "description": "Vent-only: design flow for this run, m3/h. Meaningful only when discipline is \"vent\". Absent means not stated -- there is no default, unlike every other optional field on a route."
        }
      }
    },
    "routePoint": {
      "type": "object",
      "description": "One network node. x/y are the fallback position. A symbol anchor or wall attachment resolves dynamically, so connected services follow moved devices and walls.",
      "required": [
        "id",
        "x",
        "y"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        },
        "anchor": {
          "$ref": "#/$defs/id",
          "description": "A symbol instance id this point follows."
        },
        "wallId": {
          "$ref": "#/$defs/id",
          "description": "Wall followed by this point."
        },
        "wallT": {
          "type": "integer",
          "description": "Distance from wall node a, mm."
        },
        "wallSide": {
          "enum": [
            -1,
            1
          ],
          "description": "Wall face for surface-mounted work."
        },
        "terminal": {
          "enum": [
            "source",
            "capped",
            "external"
          ],
          "description": "Explicit state of a free endpoint. \"external\" is a riser leaving the modelled storeys -- through the roof, into a crawl space, out to the street -- stated rather than linked to a floor that is not in the document."
        }
      }
    },
    "routeSegment": {
      "type": "object",
      "required": [
        "id",
        "a",
        "b"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "a": {
          "$ref": "#/$defs/id"
        },
        "b": {
          "$ref": "#/$defs/id"
        },
        "bulge": {
          "type": "number",
          "description": "DXF bulge from point a toward point b."
        }
      }
    },
    "routeContinuation": {
      "type": "object",
      "required": [
        "id",
        "ports"
      ],
      "additionalProperties": false,
      "description": "One service continuing vertically through two or more storeys.",
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "tag": {
          "type": "string",
          "description": "Optional shaft/riser identifier."
        },
        "ports": {
          "type": "array",
          "minItems": 2,
          "items": {
            "$ref": "#/$defs/routePort"
          },
          "description": "Floor-local route endpoints belonging to this vertical continuation."
        }
      }
    },
    "routePort": {
      "type": "object",
      "required": [
        "floorId",
        "routeId",
        "pointId"
      ],
      "additionalProperties": false,
      "properties": {
        "floorId": {
          "$ref": "#/$defs/id"
        },
        "routeId": {
          "$ref": "#/$defs/id"
        },
        "pointId": {
          "$ref": "#/$defs/id"
        }
      }
    },
    "furnishing": {
      "type": "object",
      "description": "One thing the plan is fitted out with. Like a stair, it stores its dimensions rather than being one fixed picture: the same unit is built 400, 600 or 800 wide, a bath is 1700 or 1800 long, and the carcass, the front, the bowl and the worktop overhang are derived from these numbers at render time. `form` says which mark is drawn and which of the optional fields below are read; the rest are ignored. The anchor (x, y) is the middle of the wall-touching edge with +y into the room for a wall-mounted form, and the middle of the footprint for a free-standing one.",
      "required": [
        "id",
        "form",
        "x",
        "y",
        "rotation",
        "width",
        "depth"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "form": {
          "enum": [
            "cabinet",
            "appliance",
            "counter",
            "toilet",
            "urinal",
            "urinal-trough",
            "bidet",
            "basin",
            "basin-trough",
            "bath",
            "shower",
            "shower-head",
            "bed",
            "seat",
            "table",
            "table-round",
            "desk",
            "rack"
          ],
          "description": "What the piece is, and so which mark is drawn. Everything from \"cabinet\" through \"shower-head\" stands against a wall; the rest stand free."
        },
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        },
        "rotation": {
          "type": "number",
          "description": "Radians, clockwise on screen."
        },
        "mirrored": {
          "type": "boolean",
          "description": "Handedness. Flips a cabinet's hinge side, a corner unit's diagonal and a worktop's drainer."
        },
        "width": {
          "type": "integer",
          "minimum": 100,
          "maximum": 6000,
          "description": "mm along the wall."
        },
        "depth": {
          "type": "integer",
          "minimum": 100,
          "maximum": 3000,
          "description": "mm into the room."
        },
        "height": {
          "type": "integer",
          "minimum": 50,
          "maximum": 6000,
          "description": "Height in mm, plinth and worktop excluded for a cabinet. Not drawn in plan; absent means the form's usual figure. The ceiling is a warehouse rack rather than a kitchen unit."
        },
        "kind": {
          "enum": [
            "base",
            "wall",
            "tall"
          ],
          "description": "Cabinet height class. It decides how the unit meets the plan's section plane at about 1200 mm: base is seen from above and tall is cut, both drawn solid; wall is entirely overhead and drawn dashed. Read only when form is \"cabinet\"; absent means base."
        },
        "front": {
          "enum": [
            "door",
            "double",
            "drawers",
            "open",
            "slide"
          ],
          "description": "What closes a cabinet front. \"open\" is shelving with no front at all. Read only when form is \"cabinet\"; absent means door."
        },
        "hinge": {
          "enum": [
            "left",
            "right"
          ],
          "description": "Which side a single door is hung, as seen from the room facing the unit. Absent means left."
        },
        "drawers": {
          "type": "integer",
          "minimum": 1,
          "maximum": 8,
          "description": "How many drawers the front is divided into. Read only when front is \"drawers\"."
        },
        "corner": {
          "type": "boolean",
          "description": "Diagonal-front corner unit."
        },
        "worktop": {
          "type": "boolean",
          "description": "Blad over the carcass, drawn as an overhang along the front."
        },
        "mark": {
          "enum": [
            "none",
            "cooktop",
            "oven",
            "microwave",
            "fridge",
            "freezer",
            "hood"
          ],
          "description": "Which toestel the appliance outline names. Read only when form is \"appliance\"; absent means the generic fixed appliance. \"hood\" hangs above the section plane and is drawn dashed."
        },
        "cistern": {
          "enum": [
            "exposed",
            "concealed"
          ],
          "description": "Where a toilet's cistern sits. Read only when form is \"toilet\"; absent means exposed."
        },
        "rails": {
          "type": "boolean",
          "description": "Grab rails either side, the accessible toilet. Read only when form is \"toilet\"."
        },
        "basins": {
          "type": "integer",
          "minimum": 1,
          "maximum": 2,
          "description": "How many bowls the run carries. Read only when form is \"basin\" or \"counter\"."
        },
        "tray": {
          "enum": [
            "none",
            "tray",
            "linear"
          ],
          "description": "What a shower stands in: the bare wet area, a tray, or a tray drained by a goot. Read only when form is \"shower\"; absent means none."
        },
        "label": {
          "type": "string",
          "description": "What the piece is called on the drawing."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour; absent means the plan's default ink."
        }
      }
    },
    "underlay": {
      "type": "object",
      "description": "A raster image traced over while drawing this floor. mmPerPixel is a ratio, not a length -- kept as a number rather than an integer, unlike every stored coordinate elsewhere in this document.",
      "required": [
        "dataUrl",
        "x",
        "y",
        "mmPerPixel",
        "opacity"
      ],
      "additionalProperties": false,
      "properties": {
        "dataUrl": {
          "type": "string",
          "pattern": "^data:image/",
          "description": "The image, downscaled and re-encoded on import."
        },
        "x": {
          "type": "integer",
          "description": "mm. Top-left corner of the image in world space."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down. Top-left corner of the image in world space."
        },
        "mmPerPixel": {
          "type": "number",
          "exclusiveMinimum": 0,
          "description": "World mm per image pixel."
        },
        "opacity": {
          "type": "number",
          "minimum": 0,
          "maximum": 1,
          "description": "0 (invisible) to 1 (opaque)."
        }
      }
    },
    "roomName": {
      "type": "object",
      "description": "A room name: the word, and the point it was written at. Which room it names is derived -- the room whose inner boundary contains the point takes it -- because rooms are found by walking the wall graph and are not stored.",
      "required": [
        "id",
        "x",
        "y",
        "name"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        },
        "name": {
          "type": "string",
          "minLength": 1
        },
        "use": {
          "enum": [
            "verblijf",
            "verkeer",
            "sanitair",
            "techniek"
          ],
          "description": "What the room is used for. Rides on the name because it is the only authored per-room anchor the document has. Absent means not stated, and only \"verblijf\" (verblijfsruimte) carries the indicative workstation, daylight-ratio and ventilation figures in core/fitout.ts."
        },
        "ceilingMm": {
          "type": "integer",
          "minimum": 1,
          "description": "Finished ceiling height in mm above the floor, where this room has a suspended ceiling of its own. Rides on the name for the reason \"use\" does. Absent means not stated, and the storey's own ceiling answers instead; a figure at or above the storey height states nothing and is ignored. Like the storey's, it changes only the wall face area."
        }
      }
    },
    "stair": {
      "type": "object",
      "description": "A placed stair. Unlike a symbol it carries its own size: the same kind is drawn 900 mm wide in a house and 1200 in a unit, and its tread count follows the storey height. Everything drawn — treads, the walking line, the arrow, the winder fan — is derived from these numbers. The anchor (x, y) is the middle of the footprint's bottom edge and +y is the direction of ascent.",
      "required": [
        "id",
        "kind",
        "x",
        "y",
        "rotation",
        "width",
        "going",
        "treads"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "kind": {
          "enum": [
            "steektrap",
            "steektrap-boven-elkaar",
            "steektrap-scheluw",
            "bordestrap",
            "bovenkwart",
            "onderkwart",
            "onder-bovenkwart",
            "rijstroken",
            "roltrap",
            "vlizotrap",
            "spiltrap-recht",
            "spiltrap-rond",
            "wenteltrap",
            "klimijzers",
            "hellingbaan"
          ],
          "description": "One of the plan-symbol sheet's stair types."
        },
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        },
        "rotation": {
          "type": "number",
          "description": "Radians, clockwise on screen."
        },
        "mirrored": {
          "type": "boolean",
          "description": "Handedness: which way the stair's first turn goes."
        },
        "counterTurn": {
          "type": "boolean",
          "description": "The second quarter turns against the first, so a stair with a quarter at each end doglegs instead of coming back beside itself. Only onder-bovenkwart turns twice; every other kind reads mirrored alone."
        },
        "width": {
          "type": "integer",
          "minimum": 200,
          "description": "mm across the flight; for a spiral, newel to rim."
        },
        "going": {
          "type": "integer",
          "minimum": 50,
          "description": "mm per tread along the walking line (aantrede)."
        },
        "treads": {
          "type": "integer",
          "minimum": 1,
          "description": "Treads drawn."
        },
        "rise": {
          "type": "integer",
          "minimum": 50,
          "description": "mm climbed. Absent means the storey height of the floor the stair stands on, which is the usual case; stating it overrides that, as a flight up to a mezzanine beside a vide does. A hellingbaan never inherits. A flight of n treads has n+1 risers, so the riser height and the walking rule follow from this, as does the tread the section plane cuts."
        },
        "well": {
          "type": "integer",
          "minimum": 0,
          "description": "The gap the kind opens: between the flights of a bordestrap, around the newel of a spiltrap. Absent means the kind's own default, which is 0 for kinds that open none."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour; absent means the plan's default ink."
        }
      }
    },
    "symbol": {
      "type": "object",
      "description": "A placed plan symbol. The anchor is (x, y); rotation is radians.",
      "required": [
        "id",
        "type",
        "x",
        "y",
        "rotation"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "type": {
          "enum": [
            "socket-single",
            "socket-earthed",
            "socket-double",
            "socket-double-earthed",
            "socket-triple",
            "socket-triple-earthed",
            "socket-shaver",
            "socket-floor",
            "switch-single",
            "switch-double",
            "switch-series",
            "switch-two-way",
            "switch-cross",
            "dimmer",
            "switch-pull",
            "push-button",
            "doorbell",
            "light-point",
            "light-wall",
            "light-fluor",
            "light-spot",
            "light-emergency",
            "outlet-tv",
            "outlet-data",
            "dist-board",
            "thermostat",
            "motion-sensor",
            "water-point",
            "water-point-hot",
            "water-point-floor",
            "water-point-floor-hot",
            "mixer-tap",
            "washing-machine",
            "dryer",
            "dishwasher",
            "boiler",
            "water-meter",
            "floor-drain",
            "waste-point",
            "gas-point",
            "radiator",
            "convector",
            "convector-pit",
            "floor-heating",
            "cv-boiler",
            "cv-manifold",
            "storage-heater",
            "heat-pump",
            "heat-pump-ground",
            "heat-pump-outdoor",
            "airco-wall",
            "airco-ceiling",
            "heat-exchanger",
            "expansion-vessel",
            "circulation-pump",
            "shutoff-valve",
            "temp-sensor",
            "mv-socket",
            "mv-switch",
            "vent-exhaust-ceiling",
            "vent-exhaust-wall",
            "vent-extract",
            "vent-supply",
            "vent-valve",
            "vent-unit",
            "wtw-unit",
            "fan",
            "emergency-exit",
            "fire-ext-co2",
            "fire-ext-powder",
            "fire-ext-foam",
            "fire-hose",
            "sprinkler",
            "fire-alarm",
            "smoke-detector",
            "heat-detector",
            "co-detector",
            "alarm-sounder",
            "alarm-beacon",
            "first-aid",
            "assembly-point",
            "fire-blanket"
          ],
          "description": "One of the library's symbol ids."
        },
        "x": {
          "type": "integer",
          "description": "mm."
        },
        "y": {
          "type": "integer",
          "description": "mm, positive down."
        },
        "rotation": {
          "type": "number",
          "description": "Radians, clockwise on screen."
        },
        "mirrored": {
          "type": "boolean"
        },
        "wallId": {
          "$ref": "#/$defs/id",
          "description": "Set when the symbol is snapped to a wall."
        },
        "color": {
          "type": "string",
          "pattern": "^#[0-9a-fA-F]{6}$",
          "description": "Pen colour. Absent means the plan's default ink. Not decoration: a verbouwtekening states existing work in black, new in red, removed in yellow."
        },
        "height": {
          "type": "integer",
          "minimum": 0,
          "description": "Mounting height above this storey's finished floor, mm. Absent means the conventional height for the symbol's type -- 300 for a wandcontactdoos, 1050 for a schakelaar, the storey height for a light point -- and a type with no convention reads as not stated rather than as zero."
        },
        "board": {
          "$ref": "#/$defs/board"
        }
      }
    },
    "board": {
      "type": "object",
      "description": "What a groepenkast is called and the groepen it distributes. Only read for symbol type \"dist-board\". Each groep is a connection point a run anchors to, so a run's groep is the kast's own label rather than typed text.",
      "required": [
        "groups"
      ],
      "additionalProperties": false,
      "properties": {
        "name": {
          "type": "string",
          "maxLength": 16,
          "description": "What the drawing calls this kast."
        },
        "groups": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/boardGroup"
          },
          "description": "In the order the kast lists them; the order the plan fans them in."
        }
      }
    },
    "boardGroup": {
      "type": "object",
      "required": [
        "id",
        "name"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "$ref": "#/$defs/id"
        },
        "name": {
          "type": "string",
          "maxLength": 16,
          "description": "What the kast labels it: \"1\", \"K1\"."
        },
        "label": {
          "type": "string",
          "description": "What it feeds. Absent means nobody said."
        }
      }
    }
  }
}