# AutoFit

Source: https://meptools.com/tools/plant-room-studio/docs/autofit/

**AutoFit** places equipment in the room for you, respecting clearances, maintenance access, and
escape routes for the code and date you choose. It's an alternative or complement to placing
equipment by hand — see [Equipment](/tools/plant-room-studio/docs/equipment) for manual placement.

Open it from the **Auto** group in the ribbon (the **AutoFit** verb). Like every non-Select verb,
it's disabled until a room exists — see [The workspace & ribbon](/tools/plant-room-studio/docs/interface).

![AutoFit's Setup tab with the doors table and equipment details](./_assets/autofit-setup.png)

## Setting up

The first time you open AutoFit on a project, press **Set up AutoFit** to initialize it with a
default rule profile and today's date (you can change both right away). The panel then shows
the **AutoFit method** switch and **Run AutoFit** at the top, with three tabs beneath:
**Setup**, **Constraints**, and **Result**.

### Setup tab

- **Code / standard** — the rule profile AutoFit checks against (for example "BS 7671:2026
  (draft)", "NFPA 70 NEC 2023 (draft)", or the draft base profile).
- **Rule date** — the edition of the standard in force on this date is applied.
- **Doors** — a table of every door in the room. Tick **Escape route** for each door AutoFit may
  route an escape path through (it never assumes a door is an exit on its own), and **Prefer for
  access** for doors maintenance and removal routes should favor.
- **Equipment details** — per equipment class, the **Voltage**, **Condition**, and **Type** the
  chosen standard needs to pick the right clearances.

**Run AutoFit** stays disabled until Setup is complete. If it's missing something, a warning
appears under the button — for example that you need to tick at least one escape-route door, or
fill in equipment details.

### Constraints tab

- **Required aisles** — **Draw aisle**, or pin one AutoFit chose on a previous run, and set its
  **Aisle width (mm)** and purpose: **Access** (people must be able to walk it to service equipment),
  **Removal** (equipment must be able to be carried out along it), and/or **Escape route** (it's
  part of an escape path).
- **Keep-out zones** — **Mark keep-out zone**; nothing will be placed inside it.

With nothing pinned the tab says "Nothing pinned — AutoFit chooses aisles itself."

Drawing an aisle or keep-out zone works like the other draw tools: **Enter** commits, **Esc**
cancels. Pressing Enter or Esc while typing in a Setup or Constraints field only affects that
field — it does not end or cancel an in-progress draw.

## Choosing a method

AutoFit offers two placement methods, picked with the **AutoFit method** switch at the top of
the panel:

| Method           | What it does                                                                                                                                                 |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Route Search** | Works out a route to every machine before it commits. Most thorough check; can take several minutes in a busy room.                                          |
| **Aisle Grid**   | Sets out the aisles first, then fills the bays between them. Fast. Needs the room's main walls square to the grid — use Route Search for a room at an angle. |

## Running

Press **Run AutoFit**. A progress overlay names the current stage and the elapsed time, with a
**Cancel** button. When it finishes, an **AutoFit result** dialog reports **Accepted N
placements**, **Parked N placements** and the turning-bay parking count. A run that finishes
only partially lists the items it could not place with a reason and offers **Apply placed items
only**, leaving the rest where they were.

**Locked equipment is never moved by AutoFit.** Tick **Lock equipment** in an item's inspector
(see [Equipment](/tools/plant-room-studio/docs/equipment)) to hold it fixed before you run.

**AutoFit removes equipment groups and adjacency relations to run**, because neither is honoured
by the placement engine — see [Equipment groups](/tools/plant-room-studio/docs/groups). **Undo**
restores them afterward.

## Reading the result

![AutoFit's Result tab with the scorecard and unit list](./_assets/autofit-result.png)

The **Result** tab shows a scorecard — counts of **reachable**, **warning**, **blocked**, and
**not assessed** units — plus a per-unit list you can filter by status and drill into. A status
line says whether the cached result still matches the document ("Result from last run · up to
date") or is stale because something changed since ("walls," "equipment," "aisles and doors,"
"settings," or "removal settings").

A room with doors on a wall that runs at an angle has a known limit: AutoFit can anchor such a
door, but it can't yet build usable floor space right up to an angled wall, so the door may open
onto nothing it can route through. Move the door onto a wall that runs straight along one of the
two floor axes, or square off that part of the room outline.

## See also

- [Equipment](/tools/plant-room-studio/docs/equipment) — the removal, voltage, and condition
  fields AutoFit's rule profiles read.
- [Equipment groups](/tools/plant-room-studio/docs/groups) — what a run does to groups.
- [Clearance validation](/tools/plant-room-studio/docs/validation) — the always-on validator,
  separate from AutoFit's own result.