Before asking which button to press, a detailer has to answer three numbers: how thick the bar is, how far its outer face sits from the edge of the concrete, and what radius it bends on. Those three numbers come from the code, not from the software.
Rebar settings in Revit are simply those three numbers copied into the model, in three different places on the Concrete tab of Revit 2027. Get them in first and every bar you place afterwards lands correctly and the schedule returns buildable figures. Skip them and you will be editing hundreds of bars member by member. For the full modelling and documentation workflow, the Institute runs a Revit Structure course.
How thick is the concrete cover before Revit even matters
Concrete cover is the distance from the face of the concrete to the outer face of the outermost bar. It keeps the steel from corroding and lets the bar bond to the concrete. TCVN 5574:2018, the Vietnamese code for concrete structures, gives minimum values by service condition, not by member name. A beam indoors and a beam outdoors take different values.
| Value | Service condition of the building structure |
|---|---|
| 20 mm | Inside a covered space with normal or low humidity, not above 75 % |
| 25 mm | Inside a covered space with raised humidity above 75 %, with no extra protection |
| 30 mm | Outdoors, with no extra protection |
| 40 mm | In the ground with no extra protection, and in footings cast on a blinding layer |
Those values are for main reinforcement. The code adds three adjustments. Precast members take 5 mm less. Secondary reinforcement takes 5 mm less than the main steel requires. And in every case the cover is never less than the bar diameter and never less than 10 mm.
The first two rules explain the 15 mm that keeps turning up in housing drawings: it is the cover to secondary steel in a dry room, that is 20 mm less 5 mm. The third rule is where software bites. Revit stores one fixed value per named cover and never compares it with the bar diameter.
Rebar settings in Revit are three jobs and one unit check
The three jobs are declaring the set of bar diameters, declaring the list of cover values, and fixing the general settings for rounding and presentation. They live in three different places, and only two of them are on the Concrete tab.
Step 1 — Check the project units before entering any number
Type UN to open Project Units. Set Discipline to Common and read the Length row: Vietnamese documents work in millimetres. Then switch Discipline to Structural.
The Structural page carries its own Bar Diameter plus five Reinforcement rows. The model used here keeps the four length rows in millimetres, Reinforcement Area in cm² and Reinforcement Volume in cm³. Get this wrong and every later entry is read in the wrong unit. Units are covered in the article on the Revit structural template.
Step 2 — Open the Concrete tab and read the two panels you need
In the 2027 release every reinforcement tool sits on the Concrete tab, not on the Structure tab. That is the first thing people used to older releases go looking for in the wrong place.
The Reinforcement panel holds seven buttons: Rebar, Path, Morphed, Area, Fabric Area, Fabric Sheet and Cover. The Settings panel next to it holds two, and those are the two dialogs to open before the first bar goes in.
The file you need to follow along
You need a model that already contains real concrete members, because cover is assigned to the faces of a member. The model here is a four-storey concrete building whose beams are M_Concrete-Rectangular Beam at 220x400 and 300x500. You also need one view that cuts through a member. Newcomers should read what Revit Structure is and structural columns in Revit first.
Bar diameters: the Rebar Bar Types of the project
Each diameter is a type in the Rebar Bar system family. The type decides the nominal diameter, the bend diameters and which hooks are available.
Step 3 — Find the diameters in the Project Browser
In the Project Browser, type into the Search box and open Families ▸ Structural Rebar ▸ Rebar Bar.
The sample project declares exactly six types: Ø6, Ø8, Ø10, Ø12, Ø16, Ø18. Naming a type after its diameter means the name tells you everything. To find out which type a placed bar belongs to, hover over it.
Step 4 — Read the Type Properties of one bar type
Double-click a type in the Project Browser and Revit opens Type Properties.
| Type parameter | Value read on the Ø8 type, and what it does |
|---|---|
| Deformation | Plain, a smooth bar. The other value is Deformed for ribbed bar |
| Bar Mass per Unit Length | 0.394 kg/m. The basis for every weight in the schedule |
| Model Bar Diameter | 8.0 mm. The diameter drawn in the 3D model |
| Bar Diameter | 8.0 mm. The nominal diameter used for calculation |
| Standard Bend Diameter | 12.0 mm. The bend diameter for ordinary bends |
| Standard Hook Bend Diameter | 12.0 mm. The bend diameter at a hook |
| Stirrup/Tie Bend Diameter | 12.0 mm. The bend diameter for stirrups and ties |
| Maximum Bend Radius | 18000.0. The largest bend radius allowed |
Step 5 — Duplicate a type to add a diameter
If a diameter is missing, do not hunt for another family. Click Duplicate, name the type after the diameter, click OK, then edit Model Bar Diameter and Bar Diameter.
Declare the whole working set once in the office template: Ø6, Ø8, Ø10, Ø12, Ø14, Ø16, Ø18, Ø20, Ø22, Ø25. Do it once and no later project has to repeat it.
Step 6 — Set the three bend diameters to the code in force
Standard Bend Diameter, Standard Hook Bend Diameter and Stirrup/Tie Bend Diameter are exactly where national codes differ. The installed content carries foreign values, so they have to be edited. On the Ø8 type of the sample model all three read 12.0 mm.
Step 7 — Set hook lengths in the Rebar Hook Lengths dialog
Still in Type Properties, click Edit on the Hook Lengths row.
The table has five columns: Rebar Hook Type, Auto Calculation, Hook Length, Tangent Length and Offset Length. The seismic tie hook Stirrup/Tie Seismic on the Ø8 type reads Hook Length 62.1 mm and Tangent Length 66.6 mm. Clear the Auto Calculation box and the length cell opens for typing.
Step 8 — Declare the steel material and the mass per metre
Material decides which row of the material takeoff the bar lands in, so do not leave the default. Bar Mass per Unit Length drives the whole steel weight schedule. One wrong digit here is a wrong tonnage for the building.
Declaring concrete cover and assigning it face by face
Step 9 — Open Rebar Cover Settings and add the values you need
Click Cover Settings on the Settings panel of the Concrete tab.
The dialog is only a list of named values. The sample model declares four rows: 15 for slabs, 40 for footings and ground beams, 50 for footings cast straight on soil, plus the Rebar Cover 1 row at 25.0 mm that Revit creates. Click Add and name the new row after its number.
Step 10 — Assign cover face by face with the Cover command
Declaring the list is only half the job. The other half is assigning a value to each face of each member. Click Cover on the Reinforcement panel and the ribbon switches to the Modify | Edit Rebar Cover contextual tab.
The status bar prompts Select Element or Face for Rebar Cover. The order comes from Autodesk's page Adjust the Rebar Cover for a Host: click Pick Elements or Pick Faces, select the member or the face, then choose a value from the Cover settings list.
Step 11 — Read the three Rebar Cover rows back in Properties
Select a concrete member and scroll the Properties palette down to the Structural group.
Rebar Cover - Top Face, Rebar Cover - Bottom Face and Rebar Cover - Other Faces show that cover belongs to a face, not to a member. The beam shown carries Rebar Cover 1 at 25 mm on the bottom and other faces, while the top row is greyed out. When a row is greyed, assign it with the Cover command instead.
Reinforcement Settings: rounding and presentation
Step 12 — Open Reinforcement Settings and read the six pages
Click Reinforcement Settings, also on the Settings panel.
The six pages are General, Reinforcement rounding, Reinforcement presentation, Area Reinforcement, Path Reinforcement and Varying Rebar Set. The General page carries three check boxes, described on Autodesk's General Reinforcement Settings page.
Step 13 — Fix how bar lengths are rounded
This is the page that matters most for buildable documents.
The sample model ticks Use reinforcement rounding and sets both Bar length and Bar segment length to Nearest with a 10 mm increment. Steel is not cut to the millimetre on site, so rounding to a multiple of 10 mm gives a schedule the site can work from. The effect shows up on a real bar straight away.
A Ø8 stirrup set in beam DX1.1 reads Bar Length 1351.4 mm with the rounded 1350 mm next to it. Segment A of 54.1 mm shows 50 mm alongside. The whole set reads Total Bar Length 12150 mm and Reinforcement Mass 4.79 kg. Fix the rounding before the first bar goes in, because changing it later moves the entire schedule.
Step 14 — Choose the default presentation of a bar set
The Reinforcement presentation page carries two boxes.
Both boxes read Show All, meaning every bar in a set is drawn. On a beam with thirty stirrups that makes the drawing dense. Many offices show only the first and last bar and annotate the spacing instead. An individual set can still be changed with the Presentation panel.
Step 15 — Save the result as an office template
These three jobs cost the most effort yet come out the same on every project of a kind. Once they are done on an empty file, save it as a template. From here the file is ready for reinforcement in revit, starting with beam reinforcement.
When Revit will not play along
| What you see | Why | What to do |
|---|---|---|
| All seven Reinforcement buttons are greyed | You are on a sheet, which holds no members | Open a plan, a section or a 3D view |
| Only Fabric Sheet is greyed | You are in a 3D view | Switch to a structural plan and start the command again |
| Rebar Cover - Top Face is greyed | That face cannot be edited from the Properties palette | Use the Cover command, click Pick Faces and pick the face |
| Bar lengths in the schedule carry tenths of a millimetre | Use reinforcement rounding is not ticked | Tick it and set Nearest with a 10 mm increment |
| The drawing is choked with stirrup lines | Rebar Set in view is on Show All | Change it on the Reinforcement presentation page, or per set on the Presentation panel |
| A bar lands in the wrong layer | No cover value has been assigned to that face | Assign it on the three Rebar Cover rows, or with the Cover command |
Six things people get wrong
| What you hear | What the 2027 release actually does | |
|---|---|---|
| Reinforcement tools live on the Structure tab | The 2027 release gathers them on the Concrete tab, in the Reinforcement and Settings panels | |
| Pick Elements and Pick Faces are on the Options Bar | Both sit on the Mode panel of the Modify \ | Edit Rebar Cover tab |
| Cover is assigned once for the whole member | It is assigned per face: Top Face, Bottom Face and Other Faces are separate | |
| Revit compares the cover with the bar diameter | Rebar Cover Settings stores one value per name; the check is yours to make | |
| The bar properties read Reinforcement Weight | Release 2027.2 reads Reinforcement Mass, beside Reinforcement Volume | |
| Rounding can be changed at any time | Lengths already generated change with it, and the schedule follows |
In short, rebar settings in revit come down to three dialogs and one unit check: Rebar Bar Types for diameters, Rebar Cover Settings for cover, Reinforcement Settings for rounding and presentation. Do all three, save the template, and the rest is placing bars.
Frequently asked questions
Is this a one-off job for every project?
Yes, if you save it as a template. The diameters, the cover list and the rounding are the same across housing projects of a kind.
Where does the 15 mm cover in Vietnamese drawings come from?
It is the cover to secondary reinforcement in a dry room: 20 mm from the table less the 5 mm adjustment allowed by TCVN 5574:2018.
How is Bar Diameter different from Model Bar Diameter?
Bar Diameter is the nominal diameter used for calculation and scheduling. Model Bar Diameter is the diameter drawn in the 3D model.
Do I have to declare every diameter up front?
No, a type can be added at any time with Duplicate. But declaring the working set up front stops the detailer having to break off mid-job.
Does rounding to 10 mm distort the quantities?
It shifts them, but towards what is actually ordered, since steel is not cut to the millimetre. The exact value still shows next to the rounded one.