Reduce file size with purge unused

- [Instructor] In this video I want to talk about a pretty simple command Purge Unused. Now the use of this command got a very specific, and straightforward purpose. Any time your file starts to grow in size, and contains a lot of elements that are no longer being used by the project team you can use this tool to help clean things up. Now there's a few reasons why you might want to do that. The most obvious is to try and reduce file size within your projects, and sometimes folks become particularly concerned with the sizes of the projects, and there's lots of reasons for that.

Takes longer to open. Takes longer to save. Takes longer to backup. Takes longer to transmit it to other folks. So if we can reduce the file size then we can assist with that, but I would caution you to not use file size as the only measure of project health. File size is just one of many things that can affect project health, and there are other things that are, frankly, way more dramatic. So, yes, try and keep your file size at a reasonable size, but a reasonable size is going to be different for every project depending on the needs of that team.

But let's go ahead, and look at what we can do, techniques we can use, to try, and eliminate things that are no longer needed in a project, and, therefore, help reduce the file size. And the most obvious tool for that is, on the Manage tab, and it's called Purge Unused. Now this is very specifically Purge Unused meaning that, if you look at this note down at the bottom here, only items that are not in use, or have no dependencies may be deleted. So, not in use is pretty obvious, right? So only things that are not being used anywhere in the project.

So, for example, I'll just expand a category here like the Doors category, and there's a revolving door in this project. And you can see here that that is currently checked. That tells us that that revolving door family can be completely purged. We are not using that family at all, and it allows us to purge the family, and its type. Now, right below that we've got Single-Flush which is in use so notice that that checkbox is grayed out. We can't check it, however, if we expand it all of these types could be purged.

So not only does Purge Unused allow you to purge the family, but it actually allows you to reach in, and purge individual types. So if there's a certain size that you know you'll never use in this project you could eliminate that. Like maybe I don't want the 30 by 80, but I do want the 30 by 84. So I could just go through, and check, and uncheck various items in that way. So that's how you can kind of see what it's actually going to purge, and what it means by dependencies is a little bit more subtle. So dependencies means when one item is actually inside of another item.

So we can nest families inside of one another, and we can nest families inside of other types of objects. So, for example, if we scroll down here, and look at the Furniture category there is a chair called Breuer chair, and that's not even here on the list. It can't be purged at all because if we expand this family here this one is using that chair. So before you would be able to purge that chair you would have to actually purge this family that contains that chair.

That's what we mean by a dependency. Another example is down here under Groups. I've got this group here called Queen, and at first you may be thinking well I wonder what that is, right? So, let me cancel out of here, and let's show you what the Queen is. So, if I'll scroll down, under Groups, Model, expand that out, and let's just take Queen here, drag it, and drop it into the file, and I'll just sort of place it out there. And zoom in, and it is quite literally a Queen bed arrangement like for a hotel.

Now this is a restaurant project so there's a pretty good chance that we don't need to lay out queen bed arrangements here in the restaurant. Now, if part of this project does include a hotel then maybe it's appropriate to have this here. So, by all means, don't purge it, but what maybe happened was somebody on the project team said well I need this chair for the waiting area, and I need this desk, and chair here for the back of office. So I remember I used those on a previous project. I'll just go copy, and paste them over here, and often that's how a lot of stuff accumulates in the project is people just copy, and paste them from other locations, and then they forget to get rid of them when they're done.

So, if I wanted to purge the queen beds, or the nightstands those options are not offered to me here under Furniture because they are being used. They are dependent on that group, and notice now the group is not even listed because I've placed it in. So I've actually gone backwards here, and I've now placed an instance in the model, and that eliminates all of those things from the list. Nightstands, queen beds, and so on. So, if I cancel this, and I delete this then under Purge Unused, under Furniture it will start to include more items now, but I still need to purge that group in order to fully purge all of those items if I no longer wanted them.

So keep that in mind. That's what dependencies means. So what that means is let's say that I wanted to just purge everything, okay? Maybe it's the end of the project. I want to archive this thing. Down here at the bottom it says there are 653 items to be purged. So I'll click OK, and I've just eliminated 653 items. That's a lot of stuff to delete without being sure, but, hey, I'm confident, right? Go back to Purge Unused, and notice that there's still 167 more items that need to be purged.

Why? Well, of those first 650 some of those had these 167 as dependencies. So until you purge the parent level thing you can't get to the dependencies. So I'll click OK again, and (chuckling) guess what? There's still 38 items that were dependent on the previous 167. So I'll OK again, and, finally, I get to a status of zero, and now I've fully purged the project. Now you might be patting yourself on the back here, and saying okay, great. Now my project is nice, and lean, and clean, and so forth, but if I go to Component, and I'm interested in that Viper chair, or the bed, you know.

Maybe there is a hotel component to this. Now notice those items aren't in the list anymore, or if I go to the Door command, and I'm interested in that revolving door. Notice those items aren't in the list, and not only that there's only one Single-Flush door. So, you know, maybe I go to a first floor plan here, and I want to do some dimensioning. So I go to Annotate, and I click on Dimension. There's only one Dimension type on the list here. Now, you might be looking at that going well that's odd.

I'm sure there was other kinds of dimensions, right? So that's an example of where somebody was too aggressive with the purging. So I'm going to use the dropdown here, and undo those three levels of purge, and just show you that, you know, when we purged there were quite a few dimension styles before purging, and after purging there was only one. So you definitely can be too aggressive if you're not careful. So I would encourage you to instead of just blindly clicking Purge Unused, and OK I would consider this quantity, and ask yourself am I really comfortable deleting 653 items? And, if not, click Check None, and then start moving down through the various categories to figure out which items you are comfortable purging, and which ones you want to keep for the future of this project.

There may be several things here that we want to maintain. So, back to Furniture, maybe I don't need the queen bed. So I could safely purge the bed. I could safely purge the nightstand. I could safely purge the wardrobe, but maybe I want to keep all the other stuff for the future. I might need some of those things, and so I'll go ahead, and click OK there. Now, sometimes it will show you the family, but only some of the types. We saw that with the door, right? So it's not showing us the door that we are using, the one size that we are using, but it's offering all the others, and I see the same thing here under Furniture.

Now if you're sure you don't ever need the 84 inch diameter table then you could purge that one type if you wanted to, but just keep in mind that that means that later if you decide you do want that size it's not on the list here, okay? So you'd have to bring that back in. You'd have to find it somewhere else, and bring that back into your project. Now, despite the fact that Purge Unused has all these options here it's actually not as comprehensive as it seems. So one place that Purge Unused ignores is your list of line styles.

So if you go to Line Styles, and expand the categories here's all the line styles in my project. Now there are several line styles here that have this A dash naming convention. Now those used to be layers in a DWG file that was previously in this project, and somebody's deleted the DWG file, but they didn't realize that all these line types got created here in the project. Well another place where you're going to see that sort of leftover stuff is on Materials, and when you bring in CAD files they will create these render materials that just have names, and colors.

So that's another place that kind of gets polluted, let's say, by DWG files. You might get line styles. You might get text types. You might get dimension types. So a lot of different things. Now, the materials will be included in the Purge Unused, but the line styles won't. So, again, if I just purge everything, and I go look at line styles notice that all of those layer names are still there. So if you think you're purging everything sometimes you're not. So not only do you want to think about Purge Unused carefully from the point of view of overdoing it, and purging too much it's also not quite as comprehensive as it implies.

So, once again, I'll click Cancel. I'll undo the purge, and then how would we get rid of these line styles? Well, these you have to just delete right here in this dialog using the Delete button. It'll warn you. You can say yes, and, if you want, you can hold the Shift key down, and select several, and delete them all at once. So that's the way you would delete items like that. Now it turns out that you can selectively delete other things in your Revit project as well. So the last thing that I want to share with you here is not using the Purge Unused command at all, but, instead, using the Project Browser.

So if we go down to the Families branch of the Project Browser, and look at each category. Each family is listed here beneath its category. So let's go back to our Furniture category, and I've already undone the previous purging so the bed is back, okay? And it currently contains that queen bed. Well, if I just select that family, and press Delete it will actually remove that family. However, it's warning me that that bed standard is actually in use somewhere in the project.

So the nice thing about this way is you get this little warning, and I can click Cancel, and investigate. Well because I undid all the previous purges that means my queen bed group is still here. If I delete that first, then go up, and try to delete the bed it will not complain. Now, if I delete something that is in use, like this dining table round with chairs, I'll get the warning again that we just talked about, but if I go ahead, and click OK this time notice that I will be deleting several elements from my project.

So, (chuckling) if you see something like that that might make you think twice, and go hmm, maybe I ought to undo that. Probably didn't want to delete all the dining seating. So those are a couple different ways that you can attempt to eliminate items that are no longer necessary within your project. Purge Unused is great because you can select several things, and purge them all in one step, but it also is potentially a little bit dangerous because you can overdo it. So I would encourage you that even though it's tempting to just go ahead, and click OK to go through all of those various checkboxes, and look carefully to make sure that you're not purging things that you'll regret later, and then you have to go, and find them, and import them back in.