Tuesday, September 12, 2006

Head & Sill Height Behavior

Did you model a rough opening height for your window that has say a sloping sill and now your head height is not accurate in your schedule? This is why.

We've recently discovered that the Head Height instance parameter in a door or window family is calculated from Sill Height + Height (easy right? wrong). It's not the Default Sill Height parameter as you would expect but rather the lowest point of your geometry that defines the Sill Height Revit uses to calculate Head Height (Head Height = 2'-8" + 4'-0" but should be 3'-0" + 4'-0") .

Raise or lower the lowest point of your door or window opening 4 inches and load it into your project file. Everything may look fine until you go to the window's properties and notice the head and sill height are just plain wrong. They will also schedule wrong unless you do the following.

To resolve this set the Defines Origin parameter for the Sill reference plane to TRUE. (red flag: be sure and check head and sill heights in your window schedule before plotting if you do decide to use these parameters). Thanks to Steve Stafford for resolving this issue.

2 comments:

Unknown said...

Ancient post, yes, but this simple explanation saved me much time and sanity to get my sill and head height parameters to correlate as I intended them to be. Thank you.

Peter2010 said...

What's the benefit of this default setup? Why not just make the sill ht. a normal parameter for user to create and control. This issue is all over the internet when one google it. It's confusing. I've tried to make the sill ht. a type but it keeps showing up as an instance even if the instance is delete in the family??!!!!!