Xrev API Tools: Increase Productivity!



Thursday, December 06, 2007

In Place families when should I use these?

In place families trip up a lot of new revit users. Sometimes its just so quick & easy to create a family on the fly in the project.

Unfortunately though they have some real negatives. For instance they typical have a big hit on your file size especially when you start making them reference surrounding geometry in the project. Also, one of the worst things you can do in Revit is start copying around the in-place families in the project...

Many new users don't realise that unlike a normal family all the copies are actually completely new families. That is, changing one, will NOT update all the others. If it repeats it needs to be an external family.

So what in-place families do I create?

Generally the only things I'll model in place occassionally are floors, stairs & ramps. Modelling monolithic stairs and ramps as floors is a great idea as you can then attach walls to them and get those connections to floors correct. This is also because of the current limitations of the stairs & ramps.

I prefer to model complex floors as in-place purely because they don't adjust when you move walls, causing sketches to occassionaly become invalid and delete your floor. This also gives you absolute control over footings, and various beams through the slab.

Another trick is with High-Rise buildings where you have complex floors that are typical over a number of levels.
  1. I'll model the first one in-place,
  2. Then whilst still in edit family mode, copy all the geometry and paste aligned into a new external generic model family and save it as say "Floors 3-9".
  3. I then switch back to the project and delete the inplace family i just made.
  4. I create a new in-place Floor family called "Level 3 Floor" and load the generic model family "Floors 3-9" into it and place it on level 3.
  5. Then finish the family.
  6. Revit then understands that this family is a floor allowing you to attach walls to it.
  7. You can then copy and paste by level to levels 4-9 and rename in the inplace families as per the level they are apply to. Yes we did just copy and inplace family, but because its contents is purely an external family there is no real overhead in doing this. Plus if we make a change to that generic model and reload it, it will update all of our floors!
Let me know if you'd like me to post any other examples...


Anonymous said...

Great! Could we get this to work when the structural consultant owns the slabs and the architect owns the walls? Architecture would have to make their own floors that structural could turn off. Am I on track here? Is there any way to avoid this?

Anonymous said...

Thanks for the tips. Questions: What about complicated ceilings? We have a couple that are laden with soffits and other height changes.
And walls: are there any dangers with making in-place family walls?


Chris said...

There are no dangers as such other than never to copy around in place families around your model as they are not like normal families. Each instance you copy is actually a new family.

Remember that if you do model a ceiling or wall inplace you'd need to model each layer of the element as a solid.

However, unless you have complex double curved ceilings you should be able to create complicated ceilings using the basic tools (ie: use special wall types for bulkheads etc).

As for the 1st question. Sorry for the late response. I just wouldn't monitor the floors in question and as such these floors would need to be manually monitored and co-ordinated. I would need to test this, unfortunately I don't have a copy of revit structure to do so...


carl c said...

Could you explain a bit more what the advantages are of doing the floors like this?

You suggest using an external generic family (containing the floor model) referenced into an in-place floor family. Why is this better than using an external floor family and bringing it in directly?

In the post, you mention that in-place floor families "don't adjust when you move walls...This also gives you absolute control over footings/beams through the slab." Just looking for a bit more to understand the distinction.


Chris said...

Hi Carl,

To answer your first question. It must be done this way as you cannot create an external family that is of the floor category. Floors are system families (roofs, walls, ceilings) which cannot exist outside of a project. This method is required to trick revit into using the generic model and having it behave as a floor.

For your second question, I find that quite often floors and ceilings try to be a little to smart when you adjust walls around the building and end up doing something you don't want them to...

As the in-place version is not associative the walls you decide when it adjusts. Yes this has its good points and bad points, but for high rise projects with repeating floors I find it invaluable.


Anonymous said...

I would like to get some advice on how to make the view reference tag on the ribbon tool bar active.
I created a match line to show the reference in between view but I had
no luck coz my view reference tool bar was grade out. Please advice.


Chris said...

The view reference tool will enable in a view that has dependent views. Select the view and use duplicate as dependent...