Revit 2027 reworked rebar. So what does REBO do?

1What changed for rebar in Revit 2027

These are the rebar items listed in Autodesk's official "What's New in Revit 2027" documentation. All of them have shipped; none of the rebar items is marked as a Tech Preview.

The Autodesk blog describes this as "when the host member changes, the rebar changes with it, and placement, splicing and spacing update automatically according to rules." Rebar that follows its host when the member changes, and copying rebar to similar members (Propagate Rebar, 2023), already existed. 2027 extends what follows to curved members and to longitudinal bars that follow ties. The "rules" here are the spacing formulas and splice rules the user enters. The release materials do not say that splice positions or development lengths are decided according to any country's reinforcement standard. Splicing has been in Revit since the 2025 version, and the lap length is either entered directly by the user or set as a user-defined multiple of the bar diameter.

This is also what users have long asked for. "Automatic rebar splitting", posted on Revit Ideas in 2017, received 86 votes and is now marked "Implemented". Its author wrote that "lap splice lengths differ for every bar diameter" and that splitting splices by hand took two weeks. On "Rebar automation like steel connections" (2022), a comment reads that "automation in precast and rebar has not progressed as much as hoped." Right after 2027 shipped, a post on Reddit r/Revit was titled "WOWOW FINALLY AUTODESK LOOKED AT THE REBAR".

2How far have rebar tools inside Revit come

This article looks only at the options for teams that use Revit. Standalone BIM platforms such as Tekla and ALLPLAN handle everything from modeling to fabrication data within their own ecosystems, so they are left out of the comparison. Below is what we confirmed from official pages for Revit's built-in features and for add-ins that run on Revit.

Inside Revit, Autodesk keeps strengthening the placement tools, while add-ins take on settings-based batch creation and drawings. The standards add-ins promote in their public materials are mostly European and US. We found no Revit add-in that states in public materials that it has Korean reinforcement standards (KCI, KSEA) built in.

3Placing the bars versus setting the conditions

Rebar automation has two layers. One is Auto-placing: creating rebar and putting it in 3D space. Most of the products in the table above work in this area. The other is Auto Configuration: deciding splice position, length and type, development method, cover thickness and order length according to the conditions.

Auto Configuration is not finished just by loading a code. Even under the same standard, which zone to stagger splices in and what length to cut stock bars to for ordering are judgments that mix site practice and experience. If those judgments stay in people's hands, the results change every time the person in charge changes, and the difference stays in the quantity sheet.

4What REBO does

REBO reads a Revit structural model, recognizes columns, beams, walls, slabs and foundations, and creates rebar according to KCI and KSEA. It does not stop at placing bars: it decides splice position and splice type, development, cover and order length according to the conditions. Once reinforcement is finalized, rebar quantities are recalculated straight away, and the results can be checked in Revit schedules. Each bar keeps its shape, length and quantity as Revit properties.

On a real building, reading 778 members and creating 67,360 bars took 9 minutes 13 seconds (internal measurement, including writing to the Revit model). Everything happens in Revit, with no switching between tools.

REBO was developed from scratch on Revit. The decision logic draws on the know-how of ChangSoft Global engineers who have planned and developed automatic reinforcement software for nearly 20 years.

5After REBO comes RV: review from the same quantity sheet

Revit 2027 puts rebar weight into schedules automatically. Add-ins also promote automated schedules and drawings. What public materials describe stops at schedules inside the model. In practice, quantities become an issue after that. When the design moves from R01 to R02, you have to answer which member's rebar increased and why, and whether this job is heavier or lighter than similar buildings the company has done.

RV is ChangSoft Global's web service: drag and drop the quantity sheets REBO produces, and they build up as your company's structural track record. Using REBO and RV together makes the following possible.

5.1See design changes member by member

Compare up to four revisions side by side in 3D. Additions show in green, changes in orange and deletions in red. Differences are calculated automatically from the total down to floor, member and member ID. Cases where the concrete shape is unchanged but only the rebar changed are flagged separately as "reinforcement condition change". Pick an item in the change list and the 3D view highlights that member; pick a member in 3D and it is found in the list.

5.2Change history stays as numbers

Concrete, formwork and rebar trends build up per revision as graphs, with the reason for each change recorded. Quantity comparison reports go straight out as Word or PDF. Even when staff change, the record of how the quantities reached today's values remains.

5.3Company baseline and reconciliation with 2D takeoff

Projects of the same use and structural type are grouped and member medians are shown, so you can see at once how far a new project departs from the company baseline. Put an estimator's 2D takeoff and the BIM quantities in the same table and the differences come out from the total down to member and floor; attach a reason to each line and issue it as a reconciliation report.

Because quantity sheets judged by REBO with the same rules build up, differences between revisions can be read as "differences caused by design changes", not "differences caused by different rules". Source files are not uploaded: quantity sheets are parsed in the browser and only numeric records are stored. RV is currently in beta and free until November 30, 2026.

6What works now and what comes in later versions

v1.0 does not replace shop drawings. Drawings are planned for v3.0. Overseas standards (ACI, Eurocode) are also on the roadmap. v2.0 and v3.0 are plans, and the schedule may change.

7Summary

With Revit 2027, the tools for placing rebar have improved further. Revit add-ins are also expanding settings-based creation and drawings. The questions left on Korean sites are who decides splices, development, cover and order lengths to KCI and KSEA, and how, and how to compare the resulting quantities across revisions and projects. REBO handles the first question inside Revit, and RV handles the second with the same quantity sheet. With a two-week trial, you can try it on your own Revit structural model. Product details are on the REBO product page.