Curved Curtain Wall Panels in Revit

Curved curtain walls are one of those things that pop up occasionally in an architectural project. If you are willing to live with a modified basic wall, HyunWoo Kim has a wonderful solution using wall sweeps. I had built a custom curved curtain panel family for a client a couple of years back and I recall the effort being a confusing mess of trigonometric functions. So when another client asked for pointers on building a curved curtain panel family, I decided to revisit the family and see if I could re-create the one I had built earlier (in Revit 2013). What I ended up with was a pleasantly clarified version without any of the trigonometric functions to muddy the waters.

Key Technique

The premise for this family is that Reference Lines can have variable radii and objects hosted on reference lines will move with these lines. This property makes it convenient to host forms on reference lines and have them move when the reference lines are moved. This is perhaps the only way (I know of) to have forms swing to varying angles.

Goals

Steps

1. Arc & Radius Parameters:

I used the Curtain Panel Template and the first step was to draw a simple arc between the left and right reference plane. I locked all the automatic constraint options. I believe that this locked the ends of the arc to the Front/Back reference plane.

The next step was to create a Radius parameter. More specifically, I designated the reference line as being the outer face of glass in the panel that I was creating.

2.  Vertical Mullion Host Work-plane Reference Lines:

Reference lines can host geometry on their work-planes and move the geometry when the line moves. I will use this property to host the vertical mullions of the panel and rotate the vertical mullions based on the radius of the curved panel. I drew two reference lines using the 'Chain' option while making sure I snapped to the intersections at either end of the panel and the center of the arc reference line in the middle.

3. Build the Curved Panel:

Now its time for the geometry I'm using the extrusion with the pick line tool in the sketch mode. I like the pick line option because it automatically makes associations (locks) with the object you are picking. In this case, I can be fairly certain that the outer face of the glass panel will follow the arced reference line. I've also set up three more parameters to control the thickness of the panel and the offset of the panel from the edges.  (See inset screen-shot from the Type Properties dialog).

4. Vertical Mullions:

The image above has two parts to it: the first is setting the reference plane as the active work-plane. The second step (lower right) is to actually draw the mullion extrusion sketch profile. The second part consists of hooking up dimensions of the mullions to parameters (lower left). This step could be accomplished with a sweep and profiles, but it would end up being way more expensive. At this point it is a good idea to flex the family to make sure nothing is broken.

5. Horizontal Mullions: 

For the horizontal mullions I decided to go with swept profiles.This is convenient if you need to change the profiles later. I hooked up the profile family with type parameters so that the types can be varied within the parent curtain panel family.

I created the sweeps using the top and bottom edges of the curved glass panel.

And that is it! One can add all sorts of features and variations to the panel, but this is the basic framework for building a curved curtain wall panel.

The files related to this project can be downloaded from my google drive here.