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Model in place in Revit: building, joining and cutting solids

Model in place in Revit 2027: the two dialogs before you draw, what the category choice settles, and three ways to combine solids with join, cut and voids.

  • Dr. Nguyen Manh Tuan
  • 9 min read
The category choice settles how the form displays, how it schedules and how it hides Photo: Diagram by the Institute of Information Technology in Civil Engineering

Working model in place in Revit means building a solid inside the project itself, with no separate library file. It suits shapes that occur exactly once: a curved reception desk, a piece of façade decoration, a planter built on site.

This article runs from the two dialogs that appear before you draw, through to joining and carving solids. To learn modelling and documentation end to end, see the Revit Architecture course.

An in-place family in Revit: when it is the right choice

The rule fits in a sentence: anything that will be reused belongs in its own .rfa file; anything that occurs only once in this project belongs in place.

An in-place solid cannot travel to another project, and using many of them makes the file heavy. Building .rfa families is covered in how to create a family in Revit, including the five form tools shared by both environments.

The tool sits on the Architecture tab, Build panel, button Component, item Model In-Place.

The Revit family category: the first dialog and three consequences

Click Model In-Place and Revit asks two questions before letting you draw. Do not click through them: the first settles three things that are hard to change later.

The Family Category and Parameters dialog Photo: The search box, the category list and the category's own parameter table
No.ComponentWhat it means
1Category search boxType a few letters to filter. Type Generic and Generic Models appears at once
2Category listAir Terminals, Casework, Ceilings, Columns, Doors and dozens more
3Family Parameters tableParameters belonging to the chosen category. For Generic Models the table is empty

The three consequences of that choice:

ConsequenceWhy
How it displaysEvery category carries its own conventions for line, colour and which views it appears in
How it schedulesSchedules filter by category. A form left as Generic Models never reaches the joinery schedule — see schedules in Revit
How it hidesVisibility/Graphics switches by category — see hiding and showing elements in Revit

When unsure, pick the category that genuinely fits rather than defaulting to Generic Models. A planter belongs in Planting or Site; a bar counter belongs in Casework.

The Name dialog and the Create tab

The Name dialog Photo: The second dialog asks for a name, prefilled from the chosen category

The second dialog asks for a name. Give it a meaningful one here, because that name appears in the Project Browser and in schedules.

The Create tab of the in-place editor Photo: The Create tab while building in place, with In-Place Editor at the far right

The ribbon is reduced to the Create tab. The six panels below are the ones this article uses; the rest are Select, Control and Connectors, which belong to services components.

PanelWhat it holds
PropertiesTwo small buttons: reopen the category dialog, and open Family Types
FormsFive solid form tools plus Void Forms for negative geometry
ModelModel Line, Component, Model Text, Opening, Model Group
DatumReference Line and Reference Plane — the framework shapes lock onto
Work PlaneSet, Show, Viewer. Click Set before drawing if the profile belongs on another plane
In-Place EditorFinish Model ends and commits the solid; Cancel Model discards it

The project locks while you build in place

The In-Place Editor panel Photo: The Finish Model and Cancel Model buttons

While an in-place solid is being built, the whole project is locked, exactly as when sketching a floor boundary. Walls cannot be selected and other tools will not open. Only Finish Model or Cancel Model releases it.

This confuses people regularly: they assume Revit has frozen when the command simply needs finishing. The tell is that the ribbon is reduced to the Create tab with the In-Place Editor panel lit.

What each form tool needs drawn first

The commonest mistake is running a tool and then not knowing what to draw. This table says how many profiles each one needs, and on which plane.

ToolWhat to draw first
ExtrusionOne closed profile on the work plane. Height goes in the Depth box
BlendTwo closed profiles drawn in turn: Base, then Top
RevolveOne closed profile and an axis line. The axis must share the profile's plane and must not cross it
SweepA path and a profile. Draw the path first; Revit then raises a perpendicular plane for the profile
Swept BlendA path and two profiles, one at each end

Every profile must be closed and non-self-intersecting. An open loop raises an error on the tick. Two nested loops make the inner one a hole — not a fault, but the quickest way to make an opening.

Each tool and the four-step Extrusion sequence are covered in how to create a family in Revit, since the same tools serve both environments.

Revit join geometry: merging several solids into one

A real component is rarely a single solid. It is usually several solids merged, with a few places carved away.

The Join menu Photo: Join, Unjoin and Switch Join Order
ItemWhat it does
Join GeometryClick the first solid, then the second. The two become one
Unjoin GeometrySeparates two joined solids
Switch Join OrderReverses the join, for when a material reads the wrong way round

Joining removes the visible edge between the solids in section, and quantities count once instead of twice. Autodesk documents the tool on Join Geometry, noting that it also works between host elements and in-place families.

Join order changes the final shape: joining A to B differs from B to A in which solid wins where two materials meet. If the result looks wrong, use Switch Join Order.

Revit cut geometry and void forms: two ways to carve

The Cut menu Photo: Cut Geometry and Uncut Geometry
ItemWhat it does
Cut GeometryClick the solid being cut first, then the solid doing the cutting
Uncut GeometryRemoves the cut and restores the solid
Join, cut or build a void Photo: Three ways to combine and carve solids, each for a different situation

Void Forms is the tidiest route when the opening is known in advance. Build one with the same five tools, simply clicking Void Forms first. A void is invisible in the project; it leaves only the cut it makes. Autodesk sets out the sequence on Create a Void Form.

One detail many people miss: a void cuts only geometry that already existed when it was made. To make it cut solids created afterwards, assign them with Cut Geometry, as Cut Geometry states plainly.

Never patch a badly drawn solid with a void. Correcting the solid is always tidier; voids belong to real openings such as a service hole or a recess.

When a cut or join refuses to run, Autodesk lists the usual messages and their causes on Cut or Join Geometry Fails.

Try it: build a reception desk in place

A thirty-minute exercise. It runs through model in place in Revit end to end; work on a model that already has walls and a floor.

  1. Go to Architecture, Component, and choose Model In-Place.
  2. In the category dialog, type Casework and select it. Note what the Family Parameters table holds.
  3. Name the solid RECEPTION-DESK and click OK.
  4. Try clicking a wall in the project. Note what happens and explain why.
  5. Click Extrusion, check the work plane, draw a closed rectangle, set Depth to 900 and click the tick.
  6. Build a second Extrusion overlapping part of the first.
  7. On Modify, Geometry panel, run Join Geometry on the two. Compare the section before and after.
  8. Build one more small solid and use Cut Geometry to carve it into the main one. Click the solid being cut first.
  9. Click Finish Model. Select the finished solid and read its category in Properties.
  10. Open a Casework schedule and check whether the solid appears.

Steps 4 and 10 are the two worth doing carefully: one shows the project lock, the other shows what the category choice really costs.

Frequently asked questions

When should I build in place rather than make a family?

Build in place for anything that occurs once in this project. Make an .rfa family for anything reused, or anything needing parameters to change size.

I cannot select walls while building a solid. Is Revit stuck?

No. The project is locked while an in-place solid is open. Click Finish Model or Cancel Model to leave.

How do I change a category I chose by mistake?

Select the solid, click Edit In-Place, then reopen the category dialog from the Properties panel. Better to choose correctly at the start, since a change drags display and scheduling with it.

Why does my void not cut a solid I just built?

A void cuts only what existed when it was created. For later solids, assign them explicitly with Cut Geometry.

About the author

Dr. Nguyen Manh Tuan — BIM lecturer at the Institute of Information Technology in Civil Engineering – Hanoi University of Civil Engineering