Auto Dims SC v5

A pyRevit script for automatic dimensioning of structural elements (walls, pylons, and structural columns) relative to grids in Revit.

What It Does

Select grids and structural elements with a box selection — the script automatically creates dimensions based on the spatial relationship between each element and its nearest grid:

Scenario	Result
Grid passes through element	Edge→Grid→Edge snap chain (row 1) + Edge→Edge overall (row 2)
Grid coincides with element edge	Grid→Edge dimension (row 1)
Grid is outside element	Grid→Edge→Edge single chain (row 1)

Additionally, the script creates grid-to-grid dimension chains (pairwise + overall) positioned near the grid bubbles.

Features

• Box selection workflow — select grids and elements in one go, press Enter
• Automatic side detection — dimensions are placed on the side closest to the nearest parallel grid; X and Y dimensions follow the same diagonal to avoid overlap
• Collision prevention — occupied zones are tracked so dimension lines don't stack on top of each other
• Element collision avoidance — dimension lines route around other walls/columns in the path
• Small text displacement — tight dimension values are nudged outward for readability
• Failure handling — Revit "not parallel" and similar errors are auto-resolved without dialogs
• Family instance support — correct reference conversion from symbol to instance geometry for columns

Usage

1. Open a plan view in Revit
2. Click the Auto Dims SC v5 button in pyRevit
3. Box-select grids and elements (walls, structural columns)
4. Press Enter

Settings

Configurable constants at the top of the script:

Parameter	Default	Description
OFFSET_1_MM	800	Row 1 offset from element (mm)
OFFSET_2_MM	1400	Row 2 offset from element (mm)
OFFSET_CHAIN_1_MM	1500	Grid chain offset from bubble (mm)
OFFSET_CHAIN_GAP_MM	700	Gap between pairwise and overall grid chains (mm)
ZERO_TOL_MM	5	Tolerance for "grid on edge" detection (mm)
INTERSECT_TOL_MM	50	Tolerance for "grid intersects element" detection (mm)
MAX_SNAP_DIST_MM	10000	Max distance to snap to a grid (mm)
DEBUG	True	Print detailed log to pyRevit output

Requirements

• Revit 2020+
• pyRevit 4.8+

Installation

Copy auto_dims_v5.py into your pyRevit extension under a pushbutton bundle, e.g.:

YourExtension.extension/
  YourTab.tab/
    YourPanel.panel/
      AutoDims.pushbutton/
        script.py          ← rename the file to script.py
        icon.png           ← optional icon

Reload pyRevit and the button will appear.

License

MIT