# How can I prevent Dynamo from placing new families at each run? **URL:** \ **Category:** Revit\ **Created:** [February 2, 2018, 1:41pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730 "2018-02-02T13:41:32Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![robertobatista](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@robertobatista](https://forum.dynamobim.com/u/robertobatista)\ **Post date:** [February 2, 2018, 1:41pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/1 "2018-02-02T13:41:32Z")
I’ve have placed several families in the project environment and I’m able to update the families or their locations without any problems as longs as long as I stay in the same session. If I close the script or it loses “connection” which sometimes happens when you open a new family, family template or project file and return to the project where dynamo was pointed too in the first place, Dynamo will place new families over the already existing families when I run the same script. This means that i’m unable to update anything in the project environment without first having to delete all placed families before I run the script. How can I prevent Dynamo from placing new families over the already existing families? ---
**Author:** ![PauLtus](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/paultus/32/48502_2.png) [@PauLtus](https://forum.dynamobim.com/u/PauLtus)\ **Post date:** [February 2, 2018, 1:50pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/2 "2018-02-02T13:50:32Z")
That’s really dependent on how you’re placing them currently. ---
**Author:** ![robertobatista](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@robertobatista](https://forum.dynamobim.com/u/robertobatista)\ **Post date:** [February 2, 2018, 1:59pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/3 "2018-02-02T13:59:19Z")
In this recent project, I have adaptive component panels placed on a points generated in Dynamo. I have walls created based on curves in Dynamo. I have roofs also created trough curves either selected in Revit or created in Dynamo. And I have several line based families. The first time I placed the families, everything went as expected. As soon as I closed that Dynamo session and reopen it and rerun the script, it places new family instances. If i’m not mistaken, new roof instances are not placed if there is an existing floor which was placed previously by Dynamo in a different session. ---
**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\ **Post date:** [February 2, 2018, 2:20pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/4 "2018-02-02T14:20:37Z")
This is expected behavior. Dynamo runs every node from scratch each time you open the file. Using some list management to drop the entire dataset early in the graph before closing, then undoing in Revit should keep the Revit work, and make it so you don’t re-create the stuff you just made the next time you open the file. ---
**Author:** ![Michael\_Kirschner2](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/michael_kirschner2/32/75576_2.png) [@Michael\_Kirschner2](https://forum.dynamobim.com/u/Michael_Kirschner2)\ **Post date:** [February 2, 2018, 2:25pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/5 "2018-02-02T14:25:03Z")
I would actually say this is not expected behavior, element rebinding should work when opening a dynamo file you have saved (thats why we save giant amounts of element binding data into the dyn file) so if it’s not working please report a bug. ---
**Author:** ![Thomas\_Vogt](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/thomas_vogt/32/40849_2.png) [@Thomas\_Vogt](https://forum.dynamobim.com/u/Thomas_Vogt)\ **Post date:** [February 2, 2018, 3:04pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/6 "2018-02-02T15:04:02Z")
also discussed here: [Running Dynamo and keeping objects created](https://forum.dynamobim.com/t/running-dynamo-and-keeping-objects-created/13302/5) ---
**Author:** ![robertobatista](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@robertobatista](https://forum.dynamobim.com/u/robertobatista)\ **Post date:** [February 2, 2018, 4:47pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/7 "2018-02-02T16:47:14Z")
So basically Dynamo should not recreate elements when the file is opened and rerun. If it does, it’s probably a bug, right? ---
**Author:** ![Michael\_Kirschner2](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/michael_kirschner2/32/75576_2.png) [@Michael\_Kirschner2](https://forum.dynamobim.com/u/Michael_Kirschner2)\ **Post date:** [February 2, 2018, 4:59pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/8 "2018-02-02T16:59:20Z")
yes, though there are types that Dynamo cannot reassociate because the revit API has no facility to update them, I think import instances are one of those cases. I know there are also some issues with nested custom nodes. ---
**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\ **Post date:** [February 3, 2018, 1:49am UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/9 "2018-02-03T01:49:37Z")
Can you share your graph? ---
**Author:** ![robertobatista](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@robertobatista](https://forum.dynamobim.com/u/robertobatista)\ **Post date:** [February 5, 2018, 1:29pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/10 "2018-02-05T13:29:30Z")
[curtain\_wall.dyn](https://forum.dynamobim.com/uploads/short-url/d4KOdb9rlrRCXnY8l0t6ig800rt.dyn) (515.1 KB) ---
**Author:** ![robertobatista](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@robertobatista](https://forum.dynamobim.com/u/robertobatista)\ **Post date:** [February 5, 2018, 1:34pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/11 "2018-02-05T13:34:08Z")
I had a similar issue with adaptive components in an AC family sometime ago. Every time I ran the script, new adaptive components where added. > [@How to update adaptive components without dynamo placing a new set of components](https://forum.dynamobim.com/t/how-to-update-adaptive-components-without-dynamo-placing-a-new-set-of-components/16714): > > I’ve create a script to place adaptive components on points. I’ve selected the edges of a generic model to use as a framework for the point. When I change the height of the generic model the framework adjusts as expected, however it places new adaptive components families on the updated framework alongside the previously placed AC’s. Every time I run the script or set dynamo on automatic and change the height parameter, a set of new components are placed. Is there node or a workflow to simply ad… ---
**Author:** ![Joseph\_Peel](https://avatars.discourse-cdn.com/v4/letter/j/ce73a5/32.png) [@Joseph\_Peel](https://forum.dynamobim.com/u/Joseph_Peel)\ **Post date:** [February 5, 2018, 3:40pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/12 "2018-02-05T15:40:22Z")
It would definitely be nice to be able to turn this on and off in dynamo, but you can also try running with Dynamo Player. I recently used the player to repeatedly place stuff in a model on different levels and the previous runs where not undone. ---
**Author:** ![cnealy](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/cnealy/32/41186_2.png) [@cnealy](https://forum.dynamobim.com/u/cnealy)\ **Post date:** [February 6, 2018, 7:24pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/13 "2018-02-06T19:24:03Z")
@Joseph_Peel I found this to be the case as well - Dynamo player was the way to go without closing and reopening Dynamo after each run/ ---
**Author:** ![solamour](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/solamour/32/153516_2.png) [@solamour](https://forum.dynamobim.com/u/solamour)\ **Post date:** [February 7, 2018, 12:00pm UTC](https://forum.dynamobim.com/t/how-can-i-prevent-dynamo-from-placing-new-families-at-each-run/18730/14 "2018-02-07T12:00:05Z")
You can also use **dummy transactions** as showcased by @Paolo_Emilio_Serra1 at the following link: [Detach Revit Output from Dynamo Graph](https://knowledge.autodesk.com/community/screencast/ba44d555-b421-4931-84d4-6ea14fc3e180)