Room Area Calculations?

[bskripac]

I have a floor plan where I am trying to do some Natural Ventilation calculations and the operable opening area for the windows must be at least 4% of the floor area of the room served. I have been able to create a calculated value in my schedule titled "Operable Window" that will show the area by using a simply formula (Area*.04).
This is my workaround because what I really want to do is have a parameter in the Room Tag calculate this value/percentage of the area. I started by trying to create it as a Shared Parameter and add it to the Room Tag, but it does not appear that you can add Shared Parameters into the Room Tags. Plus I could not find where the Area value was to assign a percentage parameter to it. Is this even possible?

[greg.mcdowell]

If I'm reading you right you'll need to create a schedule with a Project Parameter to perform the calculation and with a Shared Parameter that you will use to manually enter the calculated value.

If you set these two next to each other in the schedule and format them so they generate a total you'll find that it's really pretty easy to copy the values manually. Totaling the columns allows you to see fairly easily if you've made a mistake... both numbers should be the same (though occasionally rounding does get in the way.

[robert.manna]

I'll back Greg up on this one. Even though rooms are objects, there is no way to write forumalas into the room family in the same way that you could write a calculation formula for any family created in the family editor. Thus you're forced to do all your calculations in a schedule, then, as Greg described transcribe the info back into a parameter in order to have the information show up graphically in a view. I actually don't find the manual transcription process as annoying as I thought it would be as sometimes I need to manually override what Revit comes up with for a value, and its a good way to check through the numbers and make sure everything is playing as expected.

Another option would be to make use of mass families, but this would only work well if all your rooms were rectangles....

-R

[bskripac]

Thanks for the help, that worked out well. I did have one little hiccup when inserting the Shared Parameter into the schedule. After selecting the new shared parameter that I created I noticed that there was a check box in the lower left corner call the "Add to all elements in the category" that was unchecked. I left it unchecked and loaded it into the project and realized that I could not enter any values in the scheduled field. I deleted the shared parameter and went back through the process and this time checked the "Add to all elements in the category" and things worked out just fine. Any idea what that variable is actually doing?

[robert.manna]

As you discovered, if its not checked, it doesn't get added to all the actual objects, rather it just shows up in the schedule... I'm not exactly sure when you wouldn't want to add it to all elements, but if you were dealing with an actual family, and not room objects (which are their own beast in some ways) it might make a difference. It may also be something that rolled over from what either the MEP or Structural folks have had to do on their end....

-R

[bskripac]

Thanks lot for your help Robert, I will know for next time that the "Add to all elements in the category" needs to be checked. I appreciate your help.