Para Control

What it does

Para Control is a parameter manager. In a project it lists every project parameter binding (shared and non-shared) as one row, with its type, group, instance/type setting, vary-by-group setting and bound categories. In the family editor it lists the family's parameters, the way the Family Types dialog does. You edit rows in place, stage new parameters, duplicates, renames and deletions, and nothing touches the model until you click Apply.

It also exports the parameter list to Excel and imports edits back, and — in projects — scans loaded tags and titleblocks for shared parameters the project is missing.

Before you start

• Where: AECOtools ribbon ▸ Utils panel ▸ Para Control. The window title reads ParaControl in a project, or ParaControl — Family: <family name> in the family editor.
• Revit versions: Revit 2024, 2025, 2026 and 2027.
• Licence: Para Control is a free tool — it stays enabled even when AECOtools is not licensed.
• Open document: a project or a family must be open and active. The tool picks its mode from the active document.
• Project vs family: projects show Vary by Group and Categories columns and the Scan Missing button; families don't have these (family parameters have no categories or group variation).
• Shared parameter file: not needed to review or edit existing parameters, or to create brand-new ones. You do need Revit's shared parameter file set (Manage ▸ Shared Parameters, or Select file… inside Add Parameter) to add a parameter From shared parameter file or to add parameters found by Scan Missing.

Quick start

1. Open the project or family and click Para Control.
2. Use the filter drop-down and Search box (top right) to find the parameters you want.
3. Edit cells directly — Group Under, Instance/Type, Vary by Group, or Edit… in Categories. Changed rows turn orange.
4. Tick rows and use the toolbar — Add Parameter, Duplicate, Rename…, Delete — to stage more changes.
5. Click Apply, read the summary and warnings, and confirm with Yes.
6. The grid reloads from the model. Click Close when done.

The parameter grid

One row per parameter. Rows are sorted by name; click a column header to sort by that column.

Row colours

• Orange — the row has staged changes (edits, a new parameter, a pending rename).
• Red — the row is staged for deletion.
• Grey drop-downs — built-in family parameters; their group and instance/type can't be changed.

Filter and search

The filter drop-down offers All, Shared, Project (or Family in a family — non-shared parameters), Instance, Type and Modified (rows with unapplied changes). Search matches the parameter name, the type of parameter, the category summary, the GUID (paste one in to find it), the shared parameter file name and the creator. The status line at the bottom shows visible of total parameters | modified | checked | the shared parameter files searched.

Which shared parameter file?

A model stores a shared parameter's GUID, name, type and group — and nothing else. It does not record which file the parameter came from, and Revit itself remembers only one shared parameter file at a time (Manage → Shared Parameters). So the Shared Parameter File column is answered by looking each GUID up in the files you tell it about:

• Revit's active shared parameter file is always searched.
• SP Files… adds more files, or folders of them (subfolders included, .txt only) — point it at your office's standards folder and the column fills in for every parameter in the model.
• The list is saved per user in %LocalAppData%\AECOtools\runtime\state\ParaControl\sp-search.json, and files are read directly, so your active shared parameter file is never changed by the search.
• name.txt (+1) means the same GUID is defined in more than one searched file; hover to see them all.

Right-click a row for Copy GUID, Copy name + GUID, Copy shared parameter file path and Show shared parameter file in Explorer. Both columns are included in the Excel Export, along with Created By and Last Changed By.

Export to SP file

The other direction: take parameters that exist in this model (or family) and write them into a shared parameter file, so a model that has drifted ahead of the office file can be brought back in line. Tick the rows, click Export to SP file, and:

• Shared parameter file starts at Revit's active one; Browse… picks another. Revit can only write to its active file, so ParaControl points it at the target for the write and puts your setting back afterwards.
• Put them in group lists the groups already in that file, and Create new… adds one (created when you export).
• The list underneath shows exactly what will happen before you commit: ✓ will be written, — will be skipped, with the reason.

Each definition keeps its existing GUID, so the file entry and the parameter in the model stay the same parameter — that's the whole point of exporting rather than re-creating. Rows are skipped automatically when:

• the GUID is already in that file (nothing to do);
• the file already holds a different parameter with the same name — Revit refuses two definitions with one name, whatever group they're in. Rename one of them first;
• the parameter isn't shared (a plain project parameter, a plain family parameter or a built-in has no GUID to write);
• the row is staged — new, renamed or marked for deletion. Apply it first, because a rename gives the parameter a new GUID.

Visible and user-modifiable are written as Yes; a model doesn't record either, nor the tooltip, so they can't be carried over. The write happens straight away — Undo doesn't reverse it — and the Shared Parameter File column refreshes to show the file the parameters now live in.

What isn't recorded: shared parameter files hold GUID, name, data type, group, visible, tooltip, user-modifiable and hide-when-no-value — no author and no dates. In a workshared model the parameter element is owned like any other element, which is where Created By / Last Changed By come from; there is still no date. The nearest thing to "when" is the shared parameter file's own modified date in Explorer.

The category picker

• Only categories that accept bound parameters are listed. Type in the box at the top to filter; All / None tick or clear the visible categories.
• Set — pick a saved category set to apply it (it replaces the current ticks). Save… saves the current ticks under a name; Delete removes the selected set.
• Sets are saved per user by category name, so a set saved in one model works in any other: %LocalAppData%\AECOtools\runtime\state\ParaControl\category-sets.json.
• OK stages the new categories on the row; Cancel leaves it unchanged.

Toolbar actions

Every action stages changes in the grid. Nothing is written to the model until Apply.

The naming dialog (Rename and Duplicate)

Both Rename… and Duplicate open the same dialog, so a batch of parameters can be renamed in one pass instead of one at a time.

They apply in that order: name → find/replace → prefix → suffix, and the result is trimmed of surrounding spaces.

The Preview table shows every row's Current name and New name as you type, with a note on anything that can't proceed:

• unchanged — nothing to do for that row; it is simply left alone.
• same as another row — two rows would end up with the same name.
• name already in use — another parameter in the model has it. (For Duplicate, that includes the row being copied, which is why a copy must be named differently.)
• empty name — the fields have cleared the name entirely.

The action button stays disabled until every row is clean and at least one name actually changes. Rows that can't be renamed at all — built-in parameters, and shared parameters in a family — are listed in the dialog's warning instead of being silently dropped.

Excel import

• Columns are found by header name, so order and extra columns don't matter. Parameter Name is required. Also read: GUID, Type of Parameter, Group Under, Instance/Type (Instance or Type), Vary by Group (Yes, True or 1 = yes) and Categories (names separated by ; or ,). Kind and Discipline are export-only.
• Rows are matched to the grid by GUID first, then by name (not case-sensitive).
• A matched row can update its Group Under, Instance/Type, Vary by Group and Categories. Import can't rename a parameter or change its type. Built-in rows are skipped.
• An unmatched row is offered as Create — it needs a Type of Parameter label Para Control recognises and, in a project, at least one valid category. Blank Group Under means Data; blank Instance/Type means Instance.
• Unknown group names keep the current group; unknown category names are skipped with a warning.

Scan Missing options

In a family

• What's listed: all family parameters, including Built-in ones (as the Family Types dialog shows them). Built-in rows are read-only — no rename, delete, regroup or instance/type change — but you can Duplicate them to get an editable copy.
• Instance/Type switches in place without losing values.
• Rename is a real in-place rename for family (non-shared) parameters — values, formulas and label bindings are kept. Shared parameters can't be renamed, because their name lives in the shared parameter file; delete and add a different shared parameter instead.
• Add Parameter ▸ New family parameter creates a genuine family parameter (not shared). From shared parameter file adds the picked shared parameter.
• Duplicate creates a plain family parameter. If you choose to copy values, a source formula is copied; if there is no formula (or it can't be applied), the value is copied for each family type.
• Import creates family parameters for unmatched rows; categories and Vary by Group are ignored.
• No Categories, Vary by Group or Scan Missing, and no check for view filters or schedules on delete.

Shared parameters

• Reading: From shared parameter file lists every definition in Revit's active shared parameter file. If none is set, or the file can't be read, that option is disabled — use Select file… to browse to a .txt shared parameter file. This changes Revit's active shared parameter file, exactly as Manage ▸ Shared Parameters does, and the setting stays after you close the tool.
• Picking a definition binds it with its existing GUID, so it matches tags and other models that use the same definition.
• New definitions in a project: the Revit API can't create non-shared project parameters, so New definition, Duplicate, Rename… and Import Create all make a shared-backed parameter with a new GUID. The definition is written to a temporary file (group AECOtools ParaControl) that is deleted straight afterwards, and your active shared parameter file is restored — your own shared parameter file is not changed, and the new definition won't appear in it.
• Scan Missing is the exception: it keeps the same GUID the tag uses, and writes any definition not already in your active shared parameter file into it (in the SP file group you chose) on Apply.
• GUIDs are shown on hover over the Parameter Name, exported in the GUID column, and used first when matching imported rows.

Results and undo

• Apply first checks that every new or edited project parameter has at least one category, then shows Apply staged changes? with a count of edits, renames, new parameters and deletions, plus warnings:
  • ⚠ Instance/Type switch wipes stored values for: (projects)
  • ⚠ Deleted parameters still referenced by: view filters and schedules using a parameter you're deleting (projects)
• Everything is committed as one entry in Revit's Undo list: ParaControl: Apply Changes. Use Revit's Undo straight after closing Para Control to reverse the whole Apply.
• If a row fails, the others still apply and a message lists succeeded and problem(s). If Apply fails outright, it's rolled back and nothing changes.
• After Apply the grid reloads from the model, so staged rows show their real state.
• Close with unapplied changes asks Discard pending changes?

Troubleshooting