Back-Saving from ARCHICAD 19 to ARCHICAD 18
ARCHICAD 19 can back‐save project files to ARCHICAD 18 format only. When you back-save a project, an alert will warn you that elements and information that are not supported by the older version will be discarded.
Backward Compatibility for Library Parts
When back‐saving your ARCHICAD 19 project to version 18, any library parts that were revised for 19 will be automatically replaced by their original counterparts in version 18.
If the object in ARCHICAD 19 acquired additional parameters or functions compared to the version in ARCHICAD 18, those new features will be lost when you back‐save the object to ARCHICAD 18.
See also Labels, below.
Elements with multiple labels will retain only one single associative label in the back-saved project - the first label that was placed in Floor Plan view.
The other labels will still be there, but they will be independent (no longer associated to the element).
Moreover, most of the new Symbol Labels created for ARCHICAD 19 are not backward-compatible. If you back-save an ARCHICAD 19 project (which contains AC 19 Symbol Labels) and open it in ARCHICAD 18, most of the Labels will be shown as missing library parts, and all of them will be independent.
Dimension Texts
•Multi-line dimension texts in AC19 will be displayed in a single line in AC18, with no text loss. A paragraph symbol will indicate where the line break used to be. Re-opening the older-version file in AC19 will recreate the multi-line text.
•Dimension texts will retain their positions.
Guide Lines
Guide Lines placed in the AC19 project will be lost when back-saved to AC18.