Wall Trickery

[Brandon_Pike]

As I was chugging away at my model today I came across a rather aggravating little trick within a wall's type properties. Maybe some of you know this already, maybe some don't but you learn something new everyday. Apparently within the wall's type properties, if your wall is set to a "Foundation" function you can't use a level above as the "Top Constraint."

Example: I can't have a 12" Concrete basement wall (with a "foundation" function) using the First Floor Level as a top constraint. You will get the "Top Constraint is invalid for the Level" error message, and boy is it aggravating! It must use the Basement Floor Level. Now I can offset it until my heart's desire but it can't associate with a level above.

Just a random factoid for the day!

[tomnewsom]

I just created a Foundation function wall on my 7th floor, with top constraint as 8th floor and got no complaints...

[Brandon_Pike]

Hmm... that's interesting. Are you using 2011? I only run into this issue when I create a new wall. It looks like it only happens if I set the constraints before I place the wall. I can change the constraints after that fact, though.

[david_peterson]

Just like columns and walls, you will need model from top down. You can go back and adjust later.

[Steve_Stafford]

While placing the wall Revit resists what he describes in the original post. After the wall is placed it can be altered in the Properties Palette. A foundation wall only offers a Depth option unlike columns with offer a height/depth toggle to determine which way the column should be placed.

Got a minute? Long standing design/developer assumption, first/ground floors are designed first and a foundation is worked out by "sketching" over the first/ground floor. Drawing the foundation wall "down" from the ground level makes sense but View Range needs to be adjusted first to make it work.

Long ago I was told the developers were told the Architects design with structure above in mind while Structural Engineers design with the structure beneath them in mind. When they heard this it was interpreted that columns and walls etc should grow down when placed. Columns didn't always have the Height/Depth option, they added it to help resolve the fact that Structural Engineers usually want to place columns on a level and have them grow up too!

[david_peterson]

Absolutely.
It does depend though. Have a basement? We start there. At least that the way I've always gone with it. Kind of like construction I go from the ground up. Of course footings are always placed after wall and columns. But I may be different coming from an ACA background.
The column thing was my biggest complaint. To set the building, you really want to look at the lowest level and place a column from bottom to top. Plus the roof is usually the last thing that gets set. Seems like I'm always waiting for the Mechanical guys to tell my how big that penthouse needs to be

[Brandon_Pike]

Yeah, that assumption sounds correct. It's funny now that that I think about it; the differences in mind sets between architects and engineers. But I suppose that goes along with our line of work. Architects are concerned with how the structural elements above will affect their design, while engineers are concerned with how the structure on the current level will be supported below.

[david_peterson]

Archies look up at the ceiling design and say "Wow that looks great".
Structurals stand and the floor and wonder "Hey, what holds this up"