Groups - Again

[ajayholland]

Colleagues,

I've joined with a company that has recently switched to Revit. We have several projects that include residential or hotel towers from 20 to 40+ stories.

Our imperitives include "model everything" when possible - meaning to fill all floors with guestrooms, suites, etc., and to keep everything in a single file, although this may change with Version 9.

Nearly everyone on staff is shy of using Revit groups, as they have proven to be problematic in the past. The results of a forum search were too voluminous to comprehend. For those who have real experience in this area (successful or not) please share any guidelines that have been developed, or provide links to previous posts on the subject.

Thanks in advance for sharing any information.

~AJH

[sbrown]

For hotel units, place the interior partitions, doors and corridor walls and doors in the group. Leave the exterior wall out and the party wall out. Then in your unit blow ups add the other "stuff". There is no need to have the furniture, plumbing etc in the group. Add it to one group so you can have your typical floor plans ie, floors 3-20 show all the furn and fixtures. but the actual floors 4-20 only have walls and doors.
You may add balconies to the groups if the match exactly.

[hand471037]

Don't have anything within the Group referencing or hosted by things outside the group (even though you can).

[sbrown]

I was leaving the office when I posted. I want to make it clear what I do.

on the typical floor plan(overall) I use a groups that have all the "stuff" in them.
Then on the rest of the floors I duplicate the group and delete everything but the walls/doors, etc. Then as long as the origin point is set you can select all the instances of the various groups and swap them with the "lite" version or the 'full" version as needed.

[Rols]

Don't have anything within the Group referencing or hosted by things outside the group (even though you can).

This is a good one. I would include even floor hosted families with this. I know, it sounds silly, but here's a little scenario:

We thought we were smart by using floor hosted cabinet families in our condo unit groups instead of wall hosted. These groups were copied around the building and on several different levels. Everything is sailing along until some putz for some reason or another erases one of the floors. Now, not all of our groups are identical any more, since some of the groups are now missing cabinets, which were floor hosted, and...after many error messages, you have to remake your groups (long story short).

The best practice is to use Generic Model families. If, for some reason, you later decide that you really want that family to be hosted, you can nest a generic model family into a hosted family, but not the other way around.

[Rols]

I was leaving the office when I posted. I want to make it clear what I do.

on the typical floor plan(overall) I use a groups that have all the "stuff" in them.
Then on the rest of the floors I duplicate the group and delete everything but the walls/doors, etc. Then as long as the origin point is set you can select all the instances of the various groups and swap them with the "lite" version or the 'full" version as needed.

Excellent tip! I'm trying that one tomorrow!

As for best practices, Scott mentions a critically important point. That is the origin point. When you creat a group, a very benign looking symbol which sorta looks like the old UCS icon from Acad, appears at the center of the group. This is the group's origin point (0,0,0 in Acad-speak). It's very important that you drag this origin to the intersection of 2 grids or reference planes to "lock" a groups relative location.

When you don't do this, Revit places the origin at the enter of the group by default. You then copy your group through the building. Then, weeks later, you edit the group and move a wall or something, which changes the extents of the group, which changes the center, which moves the origin, which causes one of the copied groups to make a unique wall cleanup, which causes non-uniform groups, which, finally causes all sorts of errors.

[dgraue]

Good point Rols. Non-uniform groups get to be frustrating later in the project when they appear as units are are adjusted in design development.

[mschroeder]

My points relate to condo / hotel projects only.

Manage groups aggressively:

1. Designate a point person to manage unit groups.
2. Always name your groups.
3. Never nest groups within groups.
4. Delete unused groups.
5. Don't put ceilings in your unit group. (and disassociate ceiling sketch from walls)
6. Disallow end joins on walls that join with walls outside of the group.
7. Set explicit height for all walls within groups. (don't use top constraint with level above)


This is a start... :|