Zones are calculation instruments. They represent rooms and other definable areas/volumes in the project.
They behave like polygons with a couple exceptions. The editing palette is the same. The construction methods are different. There is no rectangle or rotated rectangle. They can be drawn as polylines, though the button doesn't look like the typical pac-man. The typical polyline palette is available.
Zones are naturally attracted to walls. They can be magic-wanded onto rooms without the spacebar. You can also designate any 2D elements except fills as 'Zone Boundary', which causes the Zone tool to treat them like walls. You can also do a conventional magic-wand under the polygon construction method.
If you need two zones in one space, such as a kitchen and breakfast room, draw a line, designated as Zone Boundary, between the spaces. Use the +Z Zones layer. If you don't draw this boundary, updating the zones will cause the multiple zones to each occupy the whole space.
There is a 'Reference Line' construction method which makes zones detect reference lines instead of wall edges. Not recommended at this time.
The height and elevation settings for zone are unusual. The 'Level' dimension is to the current story rather than project zero. Accordingly, it is usually zero. The 'Height' dimension is absolute, like with a door or window. Zones are inherently 3D, but you can use a zero height. (Example: a terrace.)
Zones have a 'Zone Number' field in addition to regular ID field. The number increments as zones are placed, but the numbers need not be unique, so you must check for duplicates yourself. Our room number format is '000', where the first digit is the story and the other digits are the room. The regular ID field can be ignored for now.
Zone Stamps: Zones can have a special object associated with them called a Zone Stamp. These objects can be scripted to display the room name and other info, to do calculations about the zone, and to hold descriptive data about the zone. More on this later. Stamps can be moved with the cursor.
Zone Categories: Zones can be assigned to user-defined categories to organize them. We have categories for Rooms, Porches/Decks, Garages, Closets, and Circulation. The colors are bound to the categories. Zone stamps are also assigned by category. Categories are attributes and are stored with the project (like fills, materials, etc), and can be modified at Options | Zone Categories.
Display Options: There are two zone-related display options.
'Zone Polygons' controls if and how the actual polygons are displayed. 'Hide color' hides them completely. 'Over' and 'Under the Fills' allows fill elements to show on top of zones, or not. In practice, you will never edit floor fills and zones at the same time, so the Over/Under choice is not important. 'Hide Color' is usually on, unless you are working on the zones themselves.
'Zone Stamps' gives a simple show/hide choice. In practice, the stamps always show and the display of zones is controlled by layer. I.e., I can't imagine a case where I would want to see the polygons but not the stamps.
Updating Zones: As walls and other zone boundaries move around, the zones do not automatically update. There are updated using the 'Update Zones' palette on the Tools Menu. Select the zones and click 'Update selected zones'. Select all is recommended; there is no harm in updating a zone that hasn't actually changed, assuming you have boundaries around them, see above. Make sure your zones are current before doing any listing of them.
Trimming zones: Zones are 3D elements. They represent space, not just area. Accordingly, they can be trimmed by other elements so they better represent the shape of a room. Zones are trimmed with the Trim Zones command on the Edit menu. Zones can be trimmed top or bottom, like walls. They can be trimmed by slabs and beams in addition to roofs.
Why trim zones? For volumetric and surface area calculations. Someday. For the time being, you can skip it.
By default, the display of zones in 3D is off. You can turn it on at Image | Elements to Show in 3D.
That's all for now.
See Also:
Archicad User Guide 1, pg. 195
Room Name Zone Stamp JAM9
Floor Areas