How to Add a Dimension

The Dimension tool places a single callout dimension between two points on the plan — the classic architectural dim with extension lines, an offset distance, a precision step, and an optional locked value. It's an annotation, which means it stacks with the rest of your annotations (text, leader text), it carries its own color and font size, and it can be brought to the front or sent to the back from the canvas context menu.

Compared to the Tape Measure tool's Dimension line mode (which drops a tape dim), the Dimension tool is the slower, more committed primitive — it has rounded precision, a value lock, and a configurable offset between the measured segment and the dim line itself. Use it when the callout matters on the printed sheet.

Open the tool

• Desktop: the Dimension button (straighten icon) lives in the annotation stack in the left toolbar, alongside the Text and Leader Text buttons.
• Mobile: the three annotation buttons collapse to one icon. Long-press the annotation icon and pick Dimension from the menu.

Place a dimension

1. Activate the Dimension tool.
2. Click the first point. The point snaps to nearby wall endpoints, fixture corners, tape dim endpoints, measurement marks, or guides — see Endpoint snapping and hover for the snap behaviour.
3. Click the second point. The dim commits — a measured line is drawn between the two points, with extension lines going out from each endpoint to the dim line offset (default 200 mm ≈ 8 inches above the measured segment), and a distance label centred between the extension lines.
4. The dim becomes part of the project's annotations and the new selection.

A near-zero-length click pair (the same point twice) is rejected — the tool refuses to commit a dim shorter than a couple of millimetres so a mis-click doesn't drop an invisible artefact.

What the dim looks like

A placed dimension has four parts:

• Two extension lines going from each measured endpoint outward to the dim-line offset.
• The dim line itself, drawn parallel to the measured segment at the offset distance.
• End markers — architectural ticks (the default arch style) or engineering arrows (eng style).
• The distance label, centred along the dim line and using the project's unit-system display.

You can hide the extension lines per dim via the entity panel's Show extension lines toggle.

Adjust the dim after placement

Select the dim (click it in Select tool, or tap on mobile) and the right-rail entity panel (desktop) or property sheet (mobile) shows the dim's properties:

• Precision — the rounding step for the displayed value. The default is 1" (25.4 mm), which matches typical residential field measurement. Other choices include 1/16", 1/8", 1/4", 1/2", and 1" for imperial; metric precision is set by the project's unit system.
• Dim style — Architectural (ticks) or Engineering (arrows). The end markers change to match.
• Show extension lines — toggle the perpendicular extension lines on or off.
• Offset distance — how far the dim line sits from the measured segment, in mm. Larger offsets clear the dim away from busy geometry; smaller offsets keep it tight to the segment.
• Font size and Color — same shape as the other annotations.
• Lock value — see below.

Lock value

The Lock value switch on a placed dim stops the displayed value from recomputing when either endpoint moves. Off (the default), the dim measures the live distance between its endpoints — drag an endpoint, the label updates.

When you toggle Lock value ON, the current rounded value is captured. From that point on, dragging either endpoint will move the visuals (the extension lines, the dim line, the label position), but the displayed number stays whatever was locked in.

Use Lock value when you want a callout that asserts a target dimension on the printed sheet — "this opening should be 32 inches" — and the underlying geometry is a placeholder you'll tighten up later. Use Lock value off when you want the callout to reflect what's actually drawn.

Toggling Lock value back OFF restores live measurement.

Dimension vs Tape Dim — which one?

You want	Reach for
A standard architectural callout with extension lines and offset	Dimension (this tool)
Lock value to assert a target on the printed sheet	Dimension (this tool)
A direct line + label between two points, no extension lines	Tape Dim (Tape Measure → Dimension line)
A quick ad-hoc measurement	Tape Measure with a mark mode
The fastest "permanent measurement" workflow	Tape Dim — fewer clicks, fewer fields

The Dimension tool and Tape Dim cover the same job from the user's side ("permanent measurement"). Tape Dim is favoured for new dim-line work; Dimension stays available because it carries Lock value and the offset stepper.

Cancel mid-placement

• Switch tools — pressing the Select tool (or any other tool) after the first click clears the pending dim. This is the reliable cancel in v1.
• Click far away — clicking a second point well off the canvas is also fine; just delete the resulting dim from the entity panel if it commits somewhere awkward.

Tips

• The default offset distance of 200 mm (about 8 inches) sits the dim line a comfortable distance off the measured segment on a typical residential plan. Bump it up to clear busy geometry, or pull it tight (50 mm) when you're labelling a thin detail.
• Architectural ticks read better at small scales; engineering arrows read better at large scales. Pick whichever matches the other dims on the same sheet.
• A locked-value dim shows the locked number even when the geometry says otherwise — useful as a callout, dangerous as a measurement. Don't lock the value on a dim you'll use to verify a fit-up later.
• The dim is an annotation, so it lives in the Annotations layer. Hiding annotations hides every Dimension entity at once. Tape Dims are NOT controlled by the annotations layer — they have their own behaviour, covered in Show or hide dimensions.