Intersect interior wall at exterior wall corner

[Anonymous]

I've searched all over this forum and all over the internet and I cannot find the answer. I am a drafting teacher planning on teaching ArchiCAD soon in my class. I am also brand new to ArchiCAD.

In the picture below I can get the interior wall to attach to the exterior wall in the middle of the exterior wall. But I am having trouble attaching the interior wall at the exterior wall corner.[/img]

[Rod Jurich]

You have your reference line on the external face of the wall.
I have always placed the reference line to the internal wall face so that your situation always cleans up.

[Barry Kelly]

As Rod said it is all to do with the reference lines.
If you turn off the "Clean wall and beam intersections" option you will find that the corner of your external wall doesn't actually exist as the walls are really only as long as their reference lines.
Therefore your internal wall at the corner is not actually touching any other wall and will not trim.
The wall midway along the external wall is touching so it does trim.

So move your reference lines of the internal walls to the inside as Rod suggests.
It is an extra step as generally you will model those walls using the external dimensions (unless you use an offset) so you have to place them and then move the reference lines.
But you only have to do it at these corner intersections.

There is a similar post here that may explain it a little more.

http://archicad-talk.graphisoft.com/viewtopic.php?p=181165

I am sure there are others.

I recall others using columns in the corners (there are posts about that somewhere) but I think this may only work for single skin walls and not multi-skin as you have used here - but I could be wrong.

Barry.

[Anonymous]

That works. Thanks for the help!

[Erich]

FWIW columns can be used with multi-skin walls as well.

[Anonymous]

Barry,
Because of this issue, I've been wondering whether to model all walls with the reference line location set to be 'core inside' as the default. Given your comment that normally we'd model the outside perimeter, can you remind me why?
Off the top of my head, I can only think of the convenience of conforming to standard brick module dimensions.

[Barry Kelly]

Brick coursing or not generally it is the external of the building that I know the dimensions for or I need a particular setback from a site boundary so again it is the external of the wall that I know the position for.
Module or coursing lengths is another reason as you mention.

It is possible to place a wall and then move the reference line if need be so if a problem does arise it can be fixed - but I only worry about it when it becomes a problem.

Barry.

[Anonymous]

Yes, setbacks is a significant one. Good point. Thanks Barry.