> ## 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.

# Level

```loft theme={"theme":{"light":"github-light","dark":"github-dark"},"languages":{"custom":["/languages/loft.json","/languages/loft-fragment.json"]}}
level L1 elev 0' height 10'-0"
```

Grids, levels, and (reserved) refplanes don't *project* datums — they **are** datums, declared directly (in carrier terms: a carrier with no recipe). Levels: plane, normal ẑ.

A level has three facts (decision 83): `elev`; `above` — the level above it, worked out from the elevations when unwritten, written (`above <level>`, `above none`) when the next level up by elevation isn't the one; and `height`, worked out from `above` when unwritten (the topmost level repeats the story below). A story height is a fact about the building, stated once — a deliberate divergence from Revit, where a level is only a plane and top-of-story is repeated on every element. Elements with a base default to their level's base and top (the file's `level` statement, or the unit's one level); `base <level> [± offset]` (revit-parity: Base Constraint + Base Offset) and `height`/`top` override per instance — `top above` reaching the file's next level up. A level has `above`; an element has `top`.

**Placement:** an elevation — `elev 0'`; every ẑ slot references the level by its id.

## Parameters

| Word                          | Accepts           | Required                                                                                                                                                                                                        | Meaning                                                        |
| ----------------------------- | ----------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------- |
| `elev`<br />`elev 0'`         | plane (normal z)  | instance · required                                                                                                                                                                                             | the level's elevation                                          |
| `above`<br />`above level.L2` | a level or `none` | instance · one of: `above` · `height` (default: the next level up by elevation)<br />**practice** — decision 83 — written only when the next level up by elevation isn't the one, or at the top (`above none`)  | the level above this one — the story reaches it                |
| `height`<br />`height 10'-0"` | length            | instance · one of: `above` · `height` (default: the next level up by elevation)<br />**practice** — decision 83 — a story height is a fact about the building, stated once; a sole level with no story is D0526 | the story (defaults from the level above, or below at the top) |

### Reserved

| Word    | Rung     | Meaning                                                                        | Arrives with                                                                              |
| ------- | -------- | ------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------- |
| `stack` | instance | which sequence of levels this one belongs to — `above` then defaults within it | a real interleaved-sequence model (a garage's 8' levels beside the podium's 10' ones)     |
| `label` | instance | what the tag prints when it is not the id                                      | a bubble or tag printing text other than the id — the grid's bubble is the one that ships |

## Datums

| Datum               | Shape | Status | Resolution | Rule                                                                                                                                                                                                                    |
| ------------------- | ----- | ------ | ---------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| *(the level plane)* | plane | core   | intrinsic  | ẑ = `elev`, normal ẑ. Referenced as `level.<id>` in every ẑ slot (`base level.L1`, `top level.L2 + 3'`, `of level.L1`); the level projects no accessor words yet (`level.L1.top` waits on the handoff's ruling 7).      |
| *(the story)*       | —     | core   | —          | The height to the level above: `height` when written; `above`'s elevation minus this one's when not; the story below, borrowed, at the top of the building. Elements with a base default to their level's base and top. |

## Roles

None — this category draws no parts of its own.