Skip to main content

Subdivide a dwelling into rooms

Break a dwelling written as one space into living room, bedrooms and wet block — without breaking the area figure for the dwelling as a whole.

File paths in the output below are absolute when you actually run these commands. They are shortened to bare filenames here for readability.

Before you start​

  • The dwelling exists as a single space and koyu check passes with zero errors.
  • You know the dwelling's region (the union of its X?..X? Y?..Y? rectangles).

The first trap — a parent with a region cannot hold children with regions​

Keep the dwelling's space line and add child spaces, and parent and children overlap.

koyu 1.0
name Subdividing a dwelling
unit mm

grid X 0 9600 12800
grid Y 0 5600 7600
level L3 8000 h:2500 slab:450
level L4 11000 slab:450

space /L3/A unit X1..X2 Y1..Y2 + X2..X3 Y1..Y1+2400 name:Type-A use:exclusive

space /L3/A/ldk  ldk     X1+3200..X2 Y1..Y1+4000 + X2..X3 Y1..Y1+2400 name:LDK
space /L3/A/bed1 bedroom X1..X1+3200 Y1+2400..Y2 name:Bedroom-1
✖ unit.muro:line 10: Space regions overlap: /L3/A and /L3/A/ldk
✖ unit.muro:line 10: Space regions overlap: /L3/A and /L3/A/bed1

Being a parent in the path does not excuse counting the area twice. /L3/A and /L3/A/ldk are parent and child in the path, and two overlapping spaces in the plan.

1. Replace the parent with a zone​

Change the dwelling's line from space to zone. A zone carries no geometry: it is an aggregation that gathers the spaces under a path prefix. It takes neither a region nor a type.

zone /L3/A name:Type-A use:exclusive

Forget to delete the space line and a space sits at the same path as a zone — ZON02, a warning.

⚠ unit-clash.muro:line 10: A space shares its path with a zone (settle on one of them): /L3/A

What a zone gathers, which attributes it passes down and how it is totalled are in zone.

2. Tile the dwelling's region with the children​

Write the children so that the union of their regions equals the dwelling's original region. Tile to wall centrelines and the zone's derived area comes out identical to the dwelling's old area.

space /L3/A/ldk  ldk     X1+3200..X2 Y1..Y1+4000 + X2..X3 Y1..Y1+2400 name:LDK
space /L3/A/bed1 bedroom X1..X1+3200 Y1+2400..Y2 name:Bedroom-1
space /L3/A/bed2 bedroom X1..X1+3200 Y1..Y1+2400 name:Bedroom-2
space /L3/A/wet  wet     X1+3200..X1+8000 Y1+4000..Y2 name:Bathroom-block
space /L3/A/hall hall    X1+8000..X2 Y1+4000..Y2 name:Entry

L-shaped rooms are unions of rectangles, written with +.

3. Write doors between the rooms​

The default between two spaces that touch is a wall with no door. You need not write the partitions themselves, but without a door nobody passes.

boundary /L3/A/ldk /L3/A/bed1 t:120 spec:LGS
  door w:800
boundary /L3/A/hall /L3/A/wet t:120 spec:LGS
  door w:700

Where the same two rooms meet along two edges of an L, pick the edge with edge:N/E/S/W.

4. Reconnect to the outside through the entry​

Once the dwelling is subdivided, what touches the corridor or the outside is no longer the dwelling but the individual rooms. Move the front door onto the boundary between the entry hall and the corridor.

boundary /L3/A/hall /L3/corridor t:180 spec:RC
  door w:900 name:A-front-door

Check it​

koyu 1.0
name Subdividing a dwelling
unit mm

grid X 0 9600 12800
grid Y 0 5600 7600
level L3 8000 h:2500 slab:450
level L4 11000 slab:450

zone /L3/A name:Type-A use:exclusive

space /L3/A/ldk  ldk     X1+3200..X2 Y1..Y1+4000 + X2..X3 Y1..Y1+2400 name:LDK
space /L3/A/bed1 bedroom X1..X1+3200 Y1+2400..Y2 name:Bedroom-1
space /L3/A/bed2 bedroom X1..X1+3200 Y1..Y1+2400 name:Bedroom-2
space /L3/A/wet  wet     X1+3200..X1+8000 Y1+4000..Y2 name:Bathroom-block
space /L3/A/hall hall    X1+8000..X2 Y1+4000..Y2 name:Entry
space /L3/corridor corridor X1..X3 Y2..Y3 name:Internal-corridor use:common

boundary /L3/A/ldk /L3/A/bed1 t:120 spec:LGS
  door w:800
boundary /L3/A/ldk /L3/A/bed2 t:120 spec:LGS
  door w:800
boundary /L3/A/ldk /L3/A/hall t:120 spec:LGS
  door w:800
boundary /L3/A/hall /L3/A/wet t:120 spec:LGS
  door w:700
boundary /L3/A/hall /L3/corridor t:180 spec:RC
  door w:900 name:A-front-door
$ npx tsx src/cli.ts check unit.muro
✔ Consistent — 6 spaces / 10 boundaries
  Structural consistency only — architectural validity is what koyu validate says, separately

Five boundaries are declared; ten are reported. The other five are default walls, derived for the pairs that touch and were never written about.

koyu stats still speaks in the language of the dwelling after the subdivision.

$ npx tsx src/cli.ts stats unit.muro
L3
  /L3/A/ldk	LDK	ldk	33.28 m2
  /L3/A/bed1	Bedroom-1	bedroom	10.24 m2
  /L3/A/bed2	Bedroom-2	bedroom	7.68 m2
  /L3/A/wet	Bathroom-block	wet	7.68 m2
  /L3/A/hall	Entry	hall	2.56 m2
  /L3/corridor	Internal-corridor	corridor	25.60 m2
  Subtotal 87.04 m2
Total 87.04 m2 (indoor floor area)
By zone (counted aggregation):
  /L3/A	Type-A	61.44 m2
  ldk: 33.28 m2
  bedroom: 17.92 m2
  wet: 7.68 m2
  hall: 2.56 m2
  corridor: 25.60 m2
By use: exclusive 61.44 m2 (70.6%) / common 25.60 m2 (29.4%)

The By zone line is the dwelling's area, and the exclusive/common split falls out without another line of source. use:exclusive is inherited by every space under the zone.

Whether you can walk from the corridor to each room is koyu doors's answer.

$ npx tsx src/cli.ts doors unit.muro /L3/A/bed1 /L3/corridor
3 doors — /L3/A/bed1 → /L3/A/ldk → /L3/A/hall → /L3/corridor

What changes when you subdivide​

  • Daylight scope does not follow the type. Only daylight:1 decides what is judged. If the dwelling carried daylight:1 before the split, move that declaration onto the rooms — otherwise the daylight judgement disappears the moment you subdivide. Which rooms are in scope is the designer's decision, not something the words ldk or bedroom settle. The procedure is in Open windows and pass the daylight check.
  • The by-type breakdown in stats gets finer. What was one unit becomes ldk, bedroom, wet and hall. Only the by-zone line absorbs the change of grain.
  • Grains may be mixed. Subdivide some dwellings and leave others whole. The bundled examples/tower/typical.muro takes type A down to rooms and leaves B through F as single unit spaces.

When the sizes and the order are what you know​

If what is settled is the size and the order of the rooms rather than their positions, write a band instead of regions. A band expands into ordinary spaces at read time, so everything after this — the zone parent, the boundaries, the openings, the checks — is unchanged.

band X X1+3200..X2+3200 Y1+4000..Y2
  space /L3..L10/A/wet  wet  w:4800 name:Bathroom-block
  space /L3..L10/A/hall hall w:1600 name:Entry

Give every member a size and the total is reconciled against the band's width at read time — a free arithmetic check on your typing. The grammar is in band.

Next​