The two-line answer
- An AoI (Area of Interest) tells detection where to look. It changes what gets found.
- A zone tells reporting how to split what was found. It changes nothing about detection.
Both are coloured polygons on the same canvas, both are drawn from the same sidebar dropdown, and both have lock and show/hide toggles. That is where the resemblance ends. This is a common source of confusion, and drawing the wrong one costs either a missed count or an export with a single undivided column.
What an AoI does
An AoI marks the part of the drawing that matters — the floor plan itself, not the title block, key or notes. When a drawing has AoIs on it, image detection only looks inside them, so symbols in the legend block are not counted as instances and clutter around the border is never searched.
Things to know about AoIs:
- Drawing an AoI locks the AoI set automatically, so it cannot be nudged while you work. Use Unlock AoIs if you need to adjust one.
- With the Auto hide AoIs preference on (the default), the first takeoff you start on a drawing locks and hides its AoIs so they stay out of the way.
- AoIs never appear as columns in the Excel export. In a PNG or PDF image export they are drawn only if they are shown on the canvas.
- A drawing does not need an AoI. Without one, detection searches the whole sheet.
See Areas of Interest.
What a zone does
A zone is a named region — a room, floor or phase — that the sidebar, the cross-drawing summary and the Excel workbook use to break your totals down. Markers are attributed to it by position: Detection and Count markers by the centre of their box, Linear and Area markers by clipping to the polygon. Anything outside every zone goes to Uncategorized.
Zones have no effect on detection whatsoever. You can draw them before or after counting, and reshape them at any time; the breakdown updates instantly.
See Creating and editing zones.
Side by side
| AoI | Zone | |
|---|---|---|
| Purpose | Limit where detection searches | Split totals by location |
| Affects what is detected | Yes | No |
| Affects the sidebar | No | Yes — Zones view groups markers under each zone |
| Affects the Excel export | No | Yes — one column per zone, plus Uncategorized |
| Typical count per drawing | One, or a few | Many — one per room or area |
| Default name | AoI 1, AoI 2… | Zone 1, Zone 2… |
| Colour | One shared colour, set in User Preferences | Each zone steps through the preset palette; editable per zone |
| Drawn with | New in the AoIs section | New in the Zones section |
| Locks itself after drawing | Yes | No — lock manually |
| Auto-hides when you start a takeoff | Yes, if the preference is on | No |
| Templates | AoI templates | Zone templates |
The third item in the menu: legends
The dropdown is titled AoIs, Legends & Zones because it also holds Legends — rectangles you draw around the drawing's symbol key. A legend rectangle is neither an AoI nor a zone: it tells Auto Detect Symbols (scan drawing) where the named, once-only symbols are, so the scan can enumerate them by their legend code and leave the key's own copy out of the count. See Drawing a legend.
The fourth section, Services , is about grouping marker groups in the sidebar rather than about the canvas. See Marker Services.
Which to draw
| You want to… | Draw |
|---|---|
| Stop the legend or title block being counted | An AoI |
| Speed up image detection on a large sheet | An AoI around the plan |
| See how many of each symbol are in each room | Zones |
| Split the export by floor, phase or fire compartment | Zones |
| Both of the above | An AoI and zones — they can overlap freely |
| Help the whole-drawing scan find named symbols | A legend rectangle |
Both on one drawing
A typical lighting layout uses all three:
- One legend rectangle around the key, so the scan can read symbol codes.
- One AoI around the floor plan, excluding the key, notes and border.
- A zone per room, drawn inside the AoI, so the export reports each room separately.
They overlap on the canvas and do not interfere with each other. Lock the AoI and the legend once detection is done; leave the zones unlocked until the layout is agreed.
Common mistakes
- Drawing a zone to keep the legend out. The zone changes nothing about detection; the legend symbols are still counted. Draw an AoI, or a legend rectangle, instead.
- Drawing an AoI per room and expecting per-room totals. AoIs do not appear in Zones view or the export. Draw zones.
- Forgetting zones until export time. Easy to spot: the workbook shows a single Total Quant column and no zone columns. Zones can be added to a finished takeoff and the export re-run.
- Renaming AoIs and zones to the same names. They are separate lists; a name on one has no link to the other.
Next steps
- Creating and editing zones — draw and manage zones.
- Areas of Interest — draw and manage AoIs.
- Drawing a legend — legend rectangles for the whole-drawing scan.
- Zones view — what zones look like in the sidebar.
- Zone templates — reuse a zone layout across drawings.