OPN — opening diagnostics

An opening (door, window and the rest) rides on a segment of a boundary. The segment is derived from the layout of the spaces, so with no segment there is nowhere to put it, and with several segments there is no telling which. These eight catch the placement, and the consistency of what was placed.

There are two idioms for position.

• A ratio — at:0.5 is a proportion of the segment length. It is clamped automatically to fit the segment.
• A grid reference — at:X2+450 is an absolute position. It means "put it there", so it is not clamped, and errors if it does not fit.

Omitted, it is at:0.5 (the middle). at points at the opening's center.

Code	severity	One line
OPN01	error	The wrong axis for hinge
OPN02	error	The openings overlap
OPN03	warning	An opening on an open boundary has no effect on passage
OPN04	error	There is no boundary segment on which to place the opening
OPN05	error	There is more than one boundary segment — ambiguous
OPN06	error	The opening is wider than the boundary segment
OPN07	error	The wrong axis for an explicit opening position
OPN08	error	An explicit opening position runs off the segment

A seg follows the same placement rules, and SEG04–SEG08 correspond one to one with OPN04–OPN08. An opening on a vertical boundary (stair, shaft, void) is not interpreted, which VRT05 says. How to get a code is on Reading a diagnostic.

An opening that could not be placed receives no further check. One that failed on any of OPN04–OPN08 is not examined for its hinge axis (OPN01), and drops out of the population for overlap (OPN02). You cannot ask the direction or the distance of something that has no position.

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

OPN01 — the wrong axis for hinge

error

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
boundary /L1/a /L1/b t:120
  door w:800 hinge:E

hinge:E: a vertical segment takes N/S

Cause — hinge says which end the hinge is at. It only means something as a compass along the segment. The two rooms here sit east and west, so the edge they share is a vertical segment running north–south, whose ends are N and S.

Fix — for a vertical segment (running north–south) use hinge:N or hinge:S; for a horizontal one (running east–west) use hinge:W or hinge:E. Omitted, it takes the starting end of the segment.

OPN02 — the openings overlap

error

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
boundary /L1/a /L1/b t:120
  door w:2000 at:0.4
  door w:2000 at:0.6

Openings overlap (door and door — center to center 800mm < the required 2000mm)

Cause — two openings on the same segment cut into each other. The required center-to-center distance is (w₁ + w₂) / 2, and the message prints both the measured and the required value.

Fix — look at the numbers in the message and move the ats apart, or narrow the widths. A ratio at is a proportion of the segment length, so the shorter the segment the smaller the real distance for the same difference in ratio. To be certain, write an absolute position with a grid reference (at:X2+900).

Note — what is checked is openings riding on the same segment. Openings on different edges (separated by edge:) are never compared, however close their coordinates.

OPN03 — an opening on an open boundary has no effect on passage

warning

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
boundary /L1/a /L1/b type:open
  door w:800

A door on an open boundary has no effect on passage (it is always passable)

Cause — open declares that there is nothing there. It is always passable to begin with, so adding a door changes nothing about passability. It is not counted by koyu doors either.

Fix — if you want the door counted (that is, a real door exists), make the boundary a wall (the default — write no type:) and put the door on it. If it is merely an opening, delete the door line.

Note — the warning does not stop the opening being checked for placement and overlap. A door on an open boundary that is wider than the segment produces OPN03 and OPN06 side by side.

OPN04 — there is no boundary segment on which to place the opening

error

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
boundary /L1/a /L1/b t:120
  door w:800 edge:N

No boundary segment can hold the door (/L1/a | /L1/b)

Cause — there is no segment where the opening's edge: narrowed to. The two rooms here sit east and west, so their shared edge is on E (seen from the a side) and there is nothing on N. The same code also appears when the boundary itself has no segment — arriving together with BND04 / BND06.

Fix — correct the compass of edge:. It is read from the rectangle of the space written first: N=+Y, S=−Y, E=+X, W=−X. X is east-positive and Y is north-positive. On a boundary with only one segment, edge: is unnecessary.

OPN05 — there is more than one boundary segment

error

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
space /out exterior
boundary /L1/a /out t:150
  door w:800
boundary /L1/b /out t:150

There is more than one boundary segment; pick an edge with edge:N/E/S/W (/L1/a | /out)

Cause — a boundary with the outside (/out and other spaces with no region) is all that remains of the room's perimeter not touching another room, and it usually splits across several edges. Where on that boundary the door goes is not settled. You may as well remember it as: placing an opening on an external wall always needs edge:.

Fix — select the side with edge:. The compass is read from the rectangle of the space written first (here /L1/a): N=+Y, S=−Y, E=+X, W=−X. To put the entrance on the south, door w:900 edge:S.

Note — the same happens between two interior rooms when an L-shaped space splits their shared edge in two. Faced with ambiguity, this check refuses rather than guesses.

OPN06 — the opening is wider than the boundary segment

error

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
boundary /L1/a /L1/b t:120
  door w:5000

The door width 5000 exceeds the boundary segment length 4000

Cause — the width is longer than the wall. The message prints the segment's real length, so you can reconcile it against the layout right there. When using an asset reference (door SD1), the width may be coming from the asset.

Fix — narrow the w, or widen the layout. To override an asset's width for one instance, write w: on the instance — the instance beats the asset.

OPN07 — the wrong axis for an explicit opening position

error

grid X 0 3600
grid Y 0 4000 8000
level L1 0 h:2400 slab:150
space /L1/a room X1..X2 Y1..Y2
space /L1/b room X1..X2 Y2..Y3
boundary /L1/a /L1/b t:120
  door w:800 at:Y1+2000

The door position Y1+2000 is on the wrong axis: a horizontal segment takes an X grid line

Cause — when writing a position as a grid reference, it is only a position if it is on the axis along the segment. The two rooms here sit north and south, so their shared edge is a horizontal segment running east–west, and a position on it is measured on the X axis.

Fix — a horizontal segment (running east–west) takes at:X…; a vertical one (running north–south) takes at:Y…. When unsure: two rooms side by side east–west share a vertical segment (Y axis); two rooms north and south share a horizontal one (X axis).

The message names the expected axis, not the one you wrote — this branch is only reached when the two disagree, so the written axis is always the opposite of the expected one.

Note — a grid reference cannot be used on a diagonal segment. On a boundary drawn with line at an angle, a grid reference does not fix a position uniquely. The same OPN07 comes out with the body The door position X2+450 cannot be used on a diagonal segment (write it as a ratio, at:0..1). Write a ratio.

OPN08 — an explicit opening position runs off the segment

error

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
boundary /L1/a /L1/b t:120
  door w:900 at:Y1+200

At Y1+200 the door (width 900) runs off the boundary segment (segment 0-4000mm, center allowed 450-3550mm)

Cause — when at is a grid reference it is not clamped. A ratio (at:0.5 and the like) is pushed back automatically to fit the segment, but a grid reference is an instruction to put it there, so if it does not fit it errors rather than moving silently. at points at the opening's center, so it must be at least w/2 inside from the end.

Fix — bring at within the "center allowed" range in the message. Here that is at:Y1+450 or more. If you only want it flush to one end, write the ratio at:0 and it is clamped hard against the end.