Cannot Change Any Dimensions

[BugFinder]

Hi,

I am having great difficulty woking out why I cannot change dimensions.

I come from a CAD background, both 2D and 3D so I'm I know what I need to do but not how to actually do it in Revit....

A typical example is shown below.  I have a curtain wall 2078 in length which I need to change.  My first attempt was to try and get my temporary dimensions visible so I hovered over this section of the wall, tabbed away and selected the wall but there were no dimensions.  So, my thinking was that if there are no dimensions maybe I need to add one; so off to the Annotate tab and linear dimension and the result of which you see below.

If I try to change this dimension, I get the dialog box you see here.  My understanding of this is that it is saying you  can fudge the display to make it say what you want but not actually do want I need which is to change the geometry to a chosen length.

Presumably this is because it is being driven from somewhere else?  If this is the case, I cannot find where.

Could someone assist with this please?

Thanks

[ToanDN]

You need to select a witness element then you will be able to type in the new value for the dimension to move the element.

[BugFinder]

I cannot find the witness element - which bit is it

I've tabbing around on the element in the screen cast below and also connected bits but cannot see anything like what you have by way of a dimension showing.

Thanks for your help.

Screencast will be displayed here after you click Post.

47caf742-f60d-467d-bd09-173fcc6258dc

[ToanDN]

Witness elements are the elements you picked to create the dimension. For example, if you placed a dimension between two walls then the two walls are witness elements.  Maybe the proper terms is 'host elements'.

[barthbradley]

Note that the Dimension needs to be unlocked in order to use. 

...are you trying to do this in Elevation with a Wall? Won't work. Change the wall height through its Instance Parameters.  

... Try Disallow Join and see if that frees up the Temporary Dimension.

[barthbradley · Accepted solution]

[BugFinder]

Thanks this seemed to do the trick.

Not sure why my screencast in my last post didn't show though....

Thanks