Dear Community members,
This month’s tip is inspired by a question from user @Bregt on the forum. The question asks how to easily model a waved railing. @Ricardo Lopez shared a nice and tidy solution that uses only Archicad’s Railing tool.
The challenge
The default use of the Railing Tool produces regular Rails—straight or curved—but won’t directly follow a wave pattern. The challenge is to create a Rail that matches a repetitive wave, staying parametric and editable from start to finish.
The solution
@Ricardo Lopez's method focuses on defining a repetitive wave pattern using empty/blank Horizontal Rails and adjusting the Top Offset of multiple Inner Posts.
Step 1: Build the wave pattern using Horizontal Rails and Inner Posts
Add hidden Horizontal Rails
- Start by adding several Horizontal Rails in the Rail Settings.
- In this example, the wave peak is at 100 cm (top Rail) and the trough/baseline at 90 cm (lowest Rail).
- Add intermediate Rails at 90 cm, 93 cm, 96 cm, 98 cm, and 100 cm to give you enough vertical steps for a smooth wave.
Tip: Set the first Rail as hidden, and the additional Rails will inherit the same setting, so you only need to configure the “hidden” behavior once.
Place Inner Posts at consistent intervals and set their Top Offsets relative to the hidden Rails
- Place the first Inner Post at the beginning of the Segment, with Distance from Previous = 0, so the pattern starts exactly at the start of the wave.
- For each Inner Post you add, set its Top Offset right away, so it aligns with one of your hidden Rails. For example, the first post is offset to Rail 1 (90 cm, baseline); the next post to Rail 2 (93 cm), then 96 cm, 98 cm, up to 100 cm (the peak), and then back down in reverse order.
- Then place the next Inner Post, for example, 8 cm away from the first.
- Continue adding Inner Posts along the Segment, always using the same spacing (e.g. 8 cm) so the wave remains smooth and consistent, until you reach the end of one full wave period.
Tip: Once you add the first Inner Post, set its dimensions and material. All following posts will adopt these properties—saving you time.
Wave pattern repeats automatically:
Remember, you only need to establish one wave Segment—the pattern will replicate along the entire railing automatically.
Step 2: Add visible Rails if needed
Add one or more visible Horizontal Rails (for example, at 100 cm as a top rail or at 60 cm as a middle support rail) to visually tie the posts together.
Step 3: Preview and refine
Switch to the 3D view and check the smoothness of the wave and repeating pattern.
- If the wave looks too “stepped,” reduce the Distance from Previous (e.g. from 8 cm down to 6 cm) and/or add more intermediate Rails.
- If it looks overly dense, increase spacing for fewer posts.
The result
You now have an editable, patterned fence.
Once the first wave Segment is set up, the rest of the railing is just repetition. Adjust the spacing and heights until the wave looks right for your design and save the setup as a favorite if you plan to reuse it. If you try this approach on other custom profiles, share your results and tips with the Community!
We’re looking for the next Community Tip! Share your best ideas for everyday challenges and get a chance to be featured in the Insights blog’s coolest series. 😉
Finally, here’s the link to the original forum discussion where you can leave kudos to @Ricardo Lopez for his helpful answer.
