Hello snti,
You are able to export all elements dimensions into IFC export translator.
There are some viewer which can export all informations you need into IFC by an xls for example.
Do you try to open an IFC with a text editor ?
You will se how this kind of file is made, it is a good way to understand how to use it.
Have a great day,
Christophe - FRANCEArchicad Designer and Teacher
Archicad 15 to 27 FRA FULL
OS 13 Ventura - MacBook Pro M2 max- 32Go RAM
"Quality is never an accident ; it's always the result of an intelligent effort" John Ruskin