space — spaces

space /L5/A/ldk ldk X1+3200..X2+3200 Y1..Y1+4000 + X2+3200..X3 Y1..Y1+2400 name:LDK floor:オーク
space /out/road-s exterior name:南側道路 road:12000

space <path> <type> [regions...] [attributes...] declares a space. Space is the primary element — a wall is not a possession of a space but a relation between two of them (boundary), and plans, areas and circulation are all derived from how spaces are laid out.

Path — identity

The first positional is a path beginning with /, and that is the space's identity in the model.

space /L5/A/ldk ldk X1..X2 Y1..Y2

• A path is also the hierarchy of aggregation. Grouping by prefix is the job of a zone: the zone /L5/A has every space whose path begins /L5/A/ beneath it.
• If the first segment is a declared level name, the space belongs to that level. /L5/A/ldk sits on L5. If it is not a level name (/site/bldg, say), the level is undetermined and must be stated with level:.
• A duplicate path is an error. Under composition, the provenance of both is shown.

Duplicate space path: /L1/a (first seen in floors/L1.muro at line 12)

Paths change when things are renamed. To join against an external register across a rename, use uid:.

Type — an open vocabulary

The second positional is the type, and it is required. Omit it and the first region is read as the type, which surfaces as a complaint about the region instead.

✖ t1.muro:line 4: space /L1/a requires a type (a word from the vocabulary)

The vocabulary of types is open: room, ldk, 厨房, tenant are all fine. Exactly two words are interpreted structurally.

Type	Interpretation
exterior	Outside. May have no region. Splits into several (/out/road-s)
void	A void through the floor. Not counted in floor area, not passable, and neither floor nor ceiling is generated

Every other type is merely carried and is never the entrance to a verdict. Whether the daylight check applies is in particular not inferred from the type — light looks at the spaces that wrote daylight:1.

The two structural words are guarded against misspelling. A word one edit away from either is refused, because the moment exteriorr parses, that space stops being outside and the gross floor area silently doubles.

✖ s2.muro:line 4: The type exteriorr looks like a misspelling of exterior (exterior is read structurally — if a different word was meant, spell it further away)

Words further away (room, yard, ldk) draw no comment.

Regions — a union of rectangles

A region is two tokens, X?..X? Y?..Y?: one range on X and one on Y. A + written as its own token joins several rectangles into a union (an L shape, for instance).

space /L1/L ldk X1..X3 Y1..Y2 + X1..X2 Y2..Y3 name:L字

• A descending spelling (X2..X1) is another way of writing the same rectangle and is normalized to ascending order.
• A zero-width region is an error.
• Rectangles overlapping within one space is GEO01; spaces on the same level overlapping is GEO02, both errors.
• The region may be omitted. exterior spaces, and spaces that exist only to be aggregated, are written without one. A space with no region cannot carry a subdivision.

A space with a region needs a level and a ceiling height. Without either, not one solid can be produced, which is the error SUF02 or SUF01.

How grid references and offsets are spelled is in positions and regions.

Writing by dimension — band members

To divide by dimension and order rather than position, use band. A space line indented under a band carries w: in place of a region.

band X X1..X3 Y1..Y2
  space /L1/ldk ldk w:3600 name:LDK
  space /L1/hall hall w:1800 name:玄関

w: may not be written on an unindented space. That refusal is what stops a member whose indentation was lost from passing silently as "a space with no region".

✖ b5.muro:line 4: w: may not be written on space (a space written by width sits indented under band)

The indented subdivision — area

An area indented under a space is an uncounted subdivision of the room: a change of floor finish, say, that appears in no area total, no room count and no graph. See area.

Level spans

If the first segment of the path has the form L3..L10, the line expands over the declared levels in ascending z. This is how a typical floor is written once.

space /L2..L9/B unit X2..X3 Y1..Y2 name:Bタイプ use:exclusive

Several paths on one line must name the same span. Indented area lines are attached to every expanded space.

The attributes

The keys writable on a space are the ones listed here plus any namespaced key containing a dot (acme.sensor:23). A key that is in neither category is the error ATT03 — the point is to stop heigh:2400 from being read past in silence while check stays green.

✖ s1.muro:line 4: /L1/a carries heigh:, which is not in the ledger (check the spelling, or add a namespace if the value is only carried — e.g. acme.heigh:2400)

They fall into three tiers. Structure is lifted into typed fields by the parser, interpreted is read for its value by core, and carry is never looked at and only transported. The tiers are set out in the three tiers of attributes.

Structure

Key	Value	Meaning
level:	a declared level name	States the level. The default is the first path segment. Needed for a grouping that spans levels (a maisonette) and whenever the path does not start with a level name (/site/bldg). An undeclared level stops with Undeclared level: level:L9
w:	positive integer mm / rest	The dimension of a band member. Not writable on a space outside a band

Interpreted

Key	Value	Meaning
h:	positive number, mm	Ceiling height. Defaults to the level's h:. Read by the height invariant and the section stack-up
use:	free word	The aggregation axis (rentable, exclusive, common, …). Inherited from a zone; a declaration on the space wins
road:	positive number, mm	The width of an exterior space — the mark of a road. site derives frontage from it
daylight:	0 / 1	Declares that the daylight check applies. Only a space with 1 gets light's 1/7 test. Out of scope by default. Not inherited
ceiling:	0 / 1	0 hangs no ceiling (an exposed soffit). One is hung by default
uid:	opaque token	Persistent identity across renames. Digits alone, or whitespace, is an error. Unique across the whole model, spanning space and zone
name:	free word	Display name, shown in drawings and listings. Without it, the last path segment is used
stair: ramp: escalator:	N / E / S / W	A vertical-circulation declaration. The key names the device, the value the direction of ascent
lift:	1	A lift declaration (it has no direction)
form:	straight / return	Whether the run turns back. Default straight
turn:	R / L	Which way it turns back. Default R
entry:	positive number, mm	The depth of the boarding floor. Default 1100
landing:	positive number, mm	The depth of an intermediate landing. Derived by default (the remainder from the target going)
riser:	positive number, mm	The maximum riser. Default 180
tread:	positive number, mm	The target going. Default 300
lane:	positive number, mm	The width of one unit or lane. 1200 by default for an escalator
slope:	positive number	The denominator of the permitted ramp gradient (slope:6 = up to 1/6). A limit for the check, not a gradient to build

Values are checked too. A non-number is ATT01 and a word outside the ledger's set is ATT02 (daylight is guarded by DAY01, and form and the directions of ascent by the RUN family). What you wrote and the tool failed to interpret does not fall silently back to the default.

$ npx tsx src/cli.ts check s3.muro --json
  "code": "DAY01",
  "message": "daylight is either 1 (in scope for the daylight check) or 0 (out of scope): /L1/a carries daylight:yes",
  "code": "ATT02",
  "message": "ceiling on /L1/a is one of 0 / 1: ceiling:2",
  "code": "ATT02",
  "message": "turn on /L1/a is one of R / L: turn:X",

Carry

Key	Meaning
floor:	Floor finish. An area may override it over an interval
spec:	The name of the thing. Carried, never interpreted
<namespace>.<key>:	Anyone may write a dotted key, and core gives its content no meaning at all (acme.sensor:23, bems.temp:22.5)

Keys a space may not carry

Three worth naming.

• site: and area: belong to a zone. On a space they are ATT03.
• underground: belongs to a level. On a space it is ATT03.
• type: belongs to a boundary. A space's type is the second positional, not an attribute.

daylight — the scope is declared

koyu 1.0
grid X 0 4000
grid Y 0 5000
level L1 0 h:2400 slab:150
space /L1/living living X1..X2 Y1..Y2 daylight:1 name:居間
space /out exterior name:外部
boundary /L1/living /out edge:S t:120
  window w:2400 h:1800

$ npx tsx src/cli.ts light d1.muro
✔ /L1/living	居間	window 4.32 m2 / floor 20.00 m2 = 1/4.6 (needs 1/7 ≈ 2.86 m2)
✔ Every room meets 1/7 — 1 room in scope (a rough judgement with no correction factor — this is validation, not what check guarantees)

A room without daylight: is outside the test. The attribute names what the tool does, not a legal category — what the 1/7 applies to is the author's call.

ceiling — the ceiling is an approximation

The ceiling surface is derived as the room's outline at the height h: fixes.

That outline does not necessarily match the real ceiling. A coffered ceiling, a bulkhead under a beam, a ceiling running continuously across several rooms, a shadow gap in front of a curtain wall — all of these are outside this resolution. The derivation is an approximation at the resolution of scheme design, not a drawn ceiling.

Only the absence of a ceiling — an exposed soffit — can be declared.

grid X 0 3600 7200
grid Y 0 4000
level L1 0 h:2400 slab:150
space /L1/a room X1..X2 Y1..Y2
space /L1/b room X2..X3 Y1..Y2 ceiling:0

The surfaces this model generates are these; /L1/b has no ceiling.

floor /L1/a -150 0
ceiling /L1/a 2370 2400
roof /L1/a 2400 2600
floor /L1/b -150 0
roof /L1/b 2400 2600

Voids, the outside, semi-outdoor spaces and vertical circulation never get a ceiling in the first place, so ceiling:0 is unnecessary there.

Vertical circulation

Stairs, ramps, escalators and lifts are declared with the key that names the device and the direction of ascent. No riser count, going, landing or gradient is written — they are derived from the region and the storey height.

space /B2..B1/ramp ramp X3..X5 Y1..Y2 name:車路 use:parking ramp:E form:return slope:6
space /B2..B1/st stair X3..X3+2600 Y2..Y2+5400 name:避難階段 use:common stair:N form:return
space /B2..B1/ev shaft X3+2600..X3+5200 Y2..Y2+5400 name:EV use:common lift:1

$ npx tsx src/cli.ts runs examples/basement/main.muro
B2→B1	lift	EV	/B2/ev
B2→B1	ramp	車路	rise 3700mm	return	slope 1/7.2	going 26800mm	/B2/ramp
B2→B1	stair	避難階段	rise 3700mm	return	21 risers of 176mm, tread 300mm	going 6000mm	/B2/st

One space carries one device (two is RUN01), and its region must be a single rectangle. Which storeys it connects belongs to the vertical boundary, not to the space — the device declaration is a rule for generating form, not a topology. The whole set of rules is in vertical circulation.

What a space produces

Writing a space produces things you did not write.

• Area — measured to wall centerlines; void and exterior are outside the gross floor area.
• Boundaries — spaces on the same level whose regions touch get a wall boundary derived for them unless one was declared.
• Semi-outdoor — a space touching an exterior across an open or air:1 boundary is treated as semi-outdoor, and neither ceiling nor roof is laid over it.
• Columns — they stand at grid intersections that fall inside a space with floor.
• Floors, ceilings, roofs — generated from the level's slab: and h:.

$ npx tsx src/cli.ts stats v1.muro
L1
  /L1/hall	ホール	hall	14.40 m2
  /L1/r	r	room	14.40 m2
  Subtotal 28.80 m2
L2
  /L2/void	吹抜け	void (not counted as floor area)
  /L2/r	r	room	14.40 m2
  Subtotal 14.40 m2
Total 43.20 m2 (indoor floor area)
  hall: 14.40 m2
  room: 28.80 m2

To subdivide, make the parent a zone

Putting a space with a region beneath a space with a region makes their regions overlap, which is GEO02.

grid X 0 3600 7200
grid Y 0 4000
level L1 0 h:2400 slab:150
space /L1/A unit X1..X3 Y1..Y2
space /L1/A/ldk ldk X1..X2 Y1..Y2

✖ z1.muro:line 4: Space regions overlap: /L1/A and /L1/A/ldk

To divide a dwelling into rooms, make the parent a zone. A zone has no geometry; it only groups by path prefix.