Question about file size when saving

[drdesignz]

This morning I saved a Revit model I am working on. In Windows Explorer I can see that the size of the file is ~25mb. Shortly after I saved my model, I did a "File > Save As..." and changed the file name to include today's date so that I could have a backup copy of my model. In Explorer I can see this file has a size of ~15mb, which is about 60% of the original size. I've opened each file separately and I haven't noticed any differences so far. So, I guess my question is, where did 40% of my file go and what was it?

[mholzer]

You must have compacted the file. Under File - Save As - Options button you can check compact file. I have noticed that it will significantly decrease the file size so a 40% decrease sounds reasonable. I'm not quite sure what compacting the file eliminates, perhaps someone else has a better explanation.

[drdesignz]

You must have compacted the file....

Actually, this option is not checked. I wonder if it is ignored and compacted anyway, because checking this option did not make the file any smaller than not having it checked.

[djn]

I have noticed that when you save a file as a new central file, it seems to do an automatic compact of the file, because you file size will decrease just as if you you had compacted the central file.

[G_J]

When you perform a "save as" Revit will rebuild the project "database" and remove any redundant space that has been allocated to elements and element defenitions that may no longer exist.

It would be advisable to perform a "save as" on a file at key stages throughout the project i.e. Prelim, Tender, and Construction as part of file maintenance.

It will help reduce the number of 'crashes' (if you get any) and also help model performance.


Regards