> ## Documentation Index
> Fetch the complete documentation index at: https://docs.loft.build/llms.txt
> Use this file to discover all available pages before exploring further.

# Roomline

```loft theme={"theme":{"light":"github-light","dark":"github-dark"},"languages":{"custom":["/languages/loft.json","/languages/loft-fragment.json"]}}
roomline from (grid.A, grid.1) to (grid.A, grid.3)
```

A room separation line (decision 69): typeless, zero width. It bounds rooms and projects one datum, the line itself; no element measures from it.

**Placement:** the line grammar, exactly as a wall's — `from … to …` and the optional carrier clause — and nothing else.

## Parameters

| Word                                  | Accepts                                  | Required            | Meaning                                                                                                                                                                                                                                                                              |
| ------------------------------------- | ---------------------------------------- | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `from`<br />`from (grid.A, grid.1)`   | line (direction z) or plane (normal xy)  | instance · required | where the line starts: a plan point, or a plane it runs from on a carrier placement<br />with a carrier clause — the `along`, `left` and `right` rows, read after `to` — `from` and `to` name the planes the line runs between; the clause's offset is a length inside it, not a row |
| `to`<br />`to (grid.B, grid.1)`       | line (direction z) or plane (normal xy)  | instance · required | where the line ends: a plan point, or a plane it runs to on a carrier placement                                                                                                                                                                                                      |
| `along`<br />`along grid.A`           | plane (normal xy) or line (direction xy) | instance · optional | the datum the line rides — it runs in that plane, or follows that line, between `from` and `to`                                                                                                                                                                                      |
| `left`<br />`at 9' left of grid.B`    | plane (normal xy)                        | instance · optional | the datum the offset measures from, on the left of travel<br />spelled `left of`, with the offset before it: `at <offset> left of <datum>`                                                                                                                                           |
| `right`<br />`at 4' right of wall.W2` | plane (normal xy)                        | instance · optional | the datum the offset measures from, on the right of travel<br />spelled `right of`, with the offset before it: `at <offset> right of <datum>`                                                                                                                                        |

### Reserved

| Word         | Rung     | Meaning                                 | Arrives with                                                                                                     |
| ------------ | -------- | --------------------------------------- | ---------------------------------------------------------------------------------------------------------------- |
| `phase`      | instance | the phase this element is created in    | the phasing era — phases are an ordered list declared in their own file, and a view looks at the model as of one |
| `demolished` | instance | the phase this element is demolished in | the phasing era — phases are an ordered list declared in their own file, and a view looks at the model as of one |

## Datums

| Datum                   | Shape | Status | Resolution | Rule                                                                                                                                                                                                                                                               |
| ----------------------- | ----- | ------ | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| *(the separation line)* | plane | core   | intrinsic  | The zero-width line itself, placed exactly as a wall's line is (decision 69): a bare carrier is its core face on the declared side, a grid is the gridline, extents join at a crossing wall's centerline. A room boundary, never a plane an element measures from. |

## Roles

None — this category draws no parts of its own.