REVIT 2025, strict rebar spacing

[hugo_gouge3BDY9]

Hello everyone,

I’d like to raise an important point regarding the management of rebar spacing in Revit, which can have real-world implications on projects, especially during the construction phase.

When using rebar distributions with a predefined spacing (e 20 cm), Revit offers three placement methods:

• Maximum spacing
• Number with spacing
• Minimum clear spacing

The "Maximum spacing" mode is very convenient because it automatically adapts to the geometry of the host. For example, if the shape of a slab changes, the distribution dynamically follows, which is highly efficient : 

👉 Issue: The actual spacing between bars is not strictly the one defined. If you set 20 cm, Revit automatically adjusts to optimize the distribution, which can result in an actual spacing of 19.3 cm, for example : 

Here’s an example when forcing the 20 cm spacing by switching to the "Fixed number with spacing" mode:

This can be problematic if rebars are tagged with a 20 cm spacing when that’s not the case in reality. On site, this may lead to overconsumption of steel or layout errors.

The "Number with spacing" mode, on the other hand, strictly respects the requested spacing (e.g., 20 cm remains 20 cm).

👉 Issue: This mode is not dynamic. It doesn’t adapt to changes in the host geometry, and it’s not possible to modify the distribution using grips, which limits its usefulness in an automated BIM workflow : 

So my question is: 

Is there a way to set a strict maximum spacing while retaining the flexibility of the "Maximum spacing" mode?
Or, how do you handle this situation in your projects? Were you aware of the difference between the displayed spacing and the actual spacing?

Thanks in advance for your feedback and for sharing your experiences!

[jay_colcombe · Accepted solution]

I would primarily use Maximum Spacing and Labels and Tags to define the Spacing output and assume this is read as is in construction.

If needed to be more specific I would lay them out this way to get to desired number then use Number with Spacing and Modify Bar to move the Last Bar into position but obviously is more time and labour intensive.

There are Third party add-ins which do allow a exact spacing and a runout at the end but come at an additional cost.

There is a proposal in development for more control over the spacing which may be the answer you are looking for exactly.

Revit - Structure Roadmap - AEC Tech Drop