AutoFit — MEP Tools
Let the tool place your equipment automatically, following code-driven clearance and access rules.
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 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.
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) 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. Undo restores them afterward.
Reading the result
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 — the removal, voltage, and condition fields AutoFit's rule profiles read.
- Equipment groups — what a run does to groups.
- Clearance validation — the always-on validator, separate from AutoFit's own result.