VRT — vertical-boundary diagnostics

Adjacency between storeys is not declared. It is derived from overlap in plan, and the default is a floor. Only the exceptions are written, and there are three.

type:	Meaning	Passage
stair	A stair — the storeys are joined by steps	Passable without a door
shaft	A lift or services shaft — the space is continuous	Impassable to people
void	A void — there is no floor here	Impassable to people

A boundary carrying one of these is a vertical boundary. It has no segment in plan, so it receives none of the horizontal checks — segments, openings, segs. Instead these six ask whether it stands up as a relation between storeys.

Code	severity	One line
VRT01	error	A vertical boundary needs a region and a level on both sides
VRT02	error	A vertical boundary spans one step between adjacent levels
VRT03	error	The spaces of a vertical boundary do not overlap in plan
VRT04	warning	The space above a void boundary is not type:void
VRT05	warning	An opening on a vertical boundary is not interpreted
VRT06	warning	A seg on a vertical boundary is not interpreted

A boundary across storeys that forgot its type: is not a vertical boundary at all, and BND03 says so. How to get a code is on Reading a diagnostic.

Every wrong example below exits 1 under koyu check --strict, producing exactly one instance of that code.

VRT01 — a vertical boundary needs a region and a level on both sides

error

grid X 0 3600
grid Y 0 4000
level L1 0 h:2400 slab:150
space /L1/a room X1..X2 Y1..Y2
space /out exterior
boundary /L1/a /out type:stair

A stair boundary is written between spaces that have both a region and a level

Cause — a vertical relation says "this part of the plan connects up and down", so unless both sides have a region and a level the position is undetermined. The partner is an exterior (no region), or a space whose level could not be determined.

Fix — make both sides real spaces with a region and a level. To write an exterior stair, stand up a stair space on each storey — one facing an exterior with open / air:1 if it is semi-outdoor — and draw type:stair between them.

Note — a boundary that drew this diagnostic receives no further check. With the premise gone, neither level adjacency (VRT02) nor overlap in plan (VRT03) can be asked.

VRT02 — a vertical boundary spans one step between adjacent levels

error

grid X 0 3600
grid Y 0 4000
level L1 0 h:2400 slab:200
level L2 3000 h:2400 slab:200
level L3 6000 h:2400 slab:200
space /L1/a room X1..X2 Y1..Y2
space /L3/a room X1..X2 Y1..Y2
boundary /L1/a /L3/a type:stair

A stair boundary is written between adjacent levels: /L1/a | /L3/a

Cause — one vertical boundary spans exactly one step between levels adjacent in z order. The example is L1 and L3, skipping L2 in between. Adjacency is decided by z, not by the order of names.

Fix — write one per step (/L1/a | /L2/a and /L2/a | /L3/a). A shaft or stair enclosure running the whole height can be declared at once with a single stack line.

grid X 0 3600
grid Y 0 4000
level L1 0 h:2400 slab:200
level L2 3000 h:2400 slab:200
level L3 6000 h:2400 slab:200
space /L1/ev shaft X1..X2 Y1..Y2
space /L2/ev shaft X1..X2 Y1..Y2
space /L3/ev shaft X1..X2 Y1..Y2
stack ev L1..L3 type:shaft

stack expands into one vertical boundary per step, so the line stays a single line however many storeys there are.

VRT03 — the spaces of a vertical boundary do not overlap in plan

error

grid X 0 3600 7200
grid Y 0 4000
level L1 0 h:2400 slab:200
level L2 3000 h:2400 slab:200
space /L1/a room X1..X2 Y1..Y2
space /L2/b room X2..X3 Y1..Y2
boundary /L1/a /L2/b type:stair

The spaces of a stair boundary do not overlap in plan: /L1/a | /L2/b

Cause — to connect up and down they must overlap in plan. The layouts of the stair or shaft differ between the storeys.

Fix — align the rectangles on both storeys. If the design shifts the stair per storey, insert a landing space in the range where they overlap.

VRT04 — the space above a void boundary is not type:void

warning

grid X 0 3600
grid Y 0 4000
level L1 0 h:2400 slab:200
level L2 3000 h:2400 slab:200
space /L1/a room X1..X2 Y1..Y2
space /L2/a room X1..X2 Y1..Y2
boundary /L1/a /L2/a type:void

The space above a void boundary is expected to be type:void: /L2/a

Cause — a type:void boundary says "there is no floor here". If the space sitting above it stays an ordinary room, it is counted as floor area despite having no floor.

Fix — make the type of the space above void.

space /L2/a void X1..X2 Y1..Y2 name:リビング上部

A void space is not counted in floor area and shows in koyu stats as void (not counted as floor area).

Note — above and below are decided by z. Whichever side you write first on the boundary, the one that is higher is the one checked.

VRT05 — an opening on a vertical boundary is not interpreted

warning

grid X 0 3600
grid Y 0 4000
level L1 0 h:2400 slab:200
level L2 3000 h:2400 slab:200
space /L1/a room X1..X2 Y1..Y2
space /L2/a room X1..X2 Y1..Y2
boundary /L1/a /L2/a type:stair
  door w:800

A door on a vertical boundary is not interpreted

Cause — an opening rides on a wall centerline segment, and a vertical boundary has no segment. Written, it affects neither daylight nor passage nor the drawing. A stair is passable without a door, and adding one does not raise the count in koyu doors.

Fix — delete the opening line. If there really is a door at the entrance to the stair, it is a door on the horizontal boundary between the stair space and the adjoining room.

Note — what is reproached is the opening's own line. The diagnostic's line points at the door line, not at the boundary line, and three openings produce three diagnostics.

VRT06 — a seg on a vertical boundary is not interpreted

warning

grid X 0 3600
grid Y 0 4000
level L1 0 h:2400 slab:200
level L2 3000 h:2400 slab:200
space /L1/a room X1..X2 Y1..Y2
space /L2/a room X1..X2 Y1..Y2
boundary /L1/a /L2/a type:stair
  seg w:800 spec:X

A seg on a vertical boundary is not interpreted

Cause — a seg names an interval of a boundary segment, and a vertical boundary has none. Neither a change of wall specification nor anything in koyu plan follows from it.

Fix — delete the seg line. To write the specification of a shaft's wall, that is a seg on the horizontal boundary between the shaft space and the adjoining room.

Note — as with VRT05, the diagnostic points at the seg's own line, and several declarations produce several diagnostics.