Drawing a curtain wall in Revit starts with something that puzzles most newcomers: there is no tool called curtain wall. You still run Wall, and simply pick a type belonging to the Curtain Wall family.
This article runs from the three layers of the system through to a finished elevation with the right panels and framing. To learn modelling and documentation end to end, see the Revit Architecture course.
A curtain wall in Revit is a wall type, not a separate tool
A curtain wall inherits everything an ordinary wall has: Base Constraint, Top Constraint, Unconnected Height. It is drawn and joined the same way too, as covered in how to draw walls in Revit.
The difference is inside: that wall is divided into cells by a grid. Each cell holds a panel, and each grid line can carry a mullion.
Getting these three straight before you start avoids most of the trouble later. Edit the wrong layer and the result is never what you wanted, and this is exactly where beginners get stuck.
The other three tools of the system sit together on the Architecture tab, Build panel.
| Tool | What it is for |
|---|---|
| Curtain System | Builds a framed system on the faces of a mass. For glazed roofs, louvers and curved surfaces |
| Curtain Grid | Adds grid lines to a curtain wall that already exists |
| Mullion | Places mullions on grid lines |
All three only mean anything once a curtain wall exists to work on.
The three curtain wall types and the constraints
Run the Wall tool and type Curtain into the Type Selector search box.
| Type | What it is |
|---|---|
| _Not Defined | No grid rule, no mullion rule. It draws as one continuous panel that you divide yourself |
| M_Exterior Glazing | Exterior glazing with a spacing rule already declared |
| M_Storefront | Shopfront glazing, a different rule, with mullions already set on the borders |
Autodesk documentation refers to a type called Curtain Wall 1, on About Curtain Walls. The Metric template of the 2027 release carries no such name; the equivalent here is _Not Defined. Do not waste time hunting for it.
| No. | Part | What it does |
|---|---|---|
| 1 | Constraints group | Base Constraint, Top Constraint and Unconnected Height decide how far the wall runs |
| 2 | Cross-Section | Set to Vertical. Switch it to Slanted for a leaning elevation |
On a real project you nearly always change Top Constraint from Unconnected to a level. A wall tied to a level grows when the storey grows; one left on Unconnected Height stays put and ends up short or too tall.
A curtain wall also has Room Bounding on by default, so it encloses rooms like a normal wall. For a small glazed opening inside a masonry wall, turn on Automatically Embed in the type and the curtain wall cuts its own hole in the host.
Grid layout: the five Layout options
The grid is not drawn by hand to begin with. It comes from the rule declared in Type Properties.
| No. | Part | What it does |
|---|---|---|
| 1 | Construction group | Function, Automatically Embed, Curtain Panel and Join Condition |
| 2 | Vertical Grid group | Layout, Spacing and Adjust for Mullion Size, the rule for the vertical direction |
| 3 | Horizontal Grid group | The same three boxes for the horizontal direction |
The Layout box is the most important control in the whole system.
| Option | What it does |
|---|---|
| None | No automatic division; add each line yourself with Curtain Grid |
| Fixed Distance | Divides at exactly the Spacing value, measured from the edge set in Justification. The last cell is usually short |
| Fixed Number | Divides into exactly the Number of cells. All equal, and they change width as the wall changes length |
| Maximum Spacing | Divides evenly so that no cell is wider than the figure given |
| Minimum Spacing | Divides evenly so that no cell is narrower than the figure given |
This is the point worth dwelling on. Drawings usually quote a round mullion spacing, 1200 or 1500 for instance. If the wall length is not a multiple of that figure, Fixed Distance leaves a narrow sliver at the far end, and it looks wrong.
The professional answer is Maximum Spacing. Enter 1500 and Revit divides evenly so that every cell matches and none exceeds 1500. The elevation comes out balanced while the glass size limit still holds.
| No. | Part | What it does |
|---|---|---|
| 1 | Vertical Grid | The Number box is how many vertical lines Revit worked out. It is greyed because it is a result, not an input |
| 2 | Horizontal Grid | The horizontal line count, with Justification measuring from the start of the wall |
| 3 | Dimensions | Length and Area of the whole wall, useful for cross-checking the cell count |
Add and edit grid lines with the Curtain Grid tool
The rule declared in the type is rarely right first time. Openings, columns and wider bays all need a line moved by hand.
| Option | What it does |
|---|---|
| All Segments | The new line runs the full height or width, crossing every cell. The one used most |
| One Segment | The line sits inside a single cell, for dividing one place only |
| All Except Picked | Runs right across but skips the cells you click, for leaving one large bay |
Autodesk sets out the three on Curtain Grid Placement Options. On the 2027 release the All Segments label is drawn clipped, so only the tail of the word shows. It is a display fault; the button works correctly.
A line added by hand remembers an absolute position, while a line born of the rule moves as the wall lengthens. So declare the rule for the bulk of the wall, then add the few special lines by hand.
To hold a hand-placed line in position, select it and click the padlock that appears beside it. A locked line stays put when the wall changes size, and that is how an opening keeps its place.
Revit mullion: set it in the type or place it by hand
Mullions arrive two ways: declared in the type so that every grid line carries one, or placed segment by segment with the Mullion tool. The first is fast, the second exact.
| Option | What it does |
|---|---|
| Grid Line | Places on a whole grid line, edge to edge |
| Grid Line Segment | Places on one segment of a line, that is one side of one cell |
| All Grid Lines | Places on every grid line in one click. The quickest way to start |
The Type Selector for the Mullion tool holds six families: three straight sections and three corner sections for where two curtain walls meet.
| No. | Part | What it does |
|---|---|---|
| 1 | Construction group | Profile is the section, Position the orientation, Thickness the depth measured perpendicular to the glass |
| 2 | Width on side 1 and 2 | The width either side of the grid line; added together they give the face width |
Those two separate widths repay attention. A real aluminium mullion is rarely symmetrical about the grid line, so declaring different widths each side describes what is actually built.
The supplied mullions are solid rectangles. Real aluminium sections are hollow, with grooves and glazing beads. For a correct section drawing, build your own profile and pick it in the Profile box, using the family workflow in how to create a Revit family.
Curtain panel: what fills each cell, and how to select one
The Curtain Panel box in Type Properties decides what fills every cell.
| Value | What it is |
|---|---|
| None | An empty cell with nothing in it. The default in the Metric template |
| System Panel : Glazed | Glass, the value a real curtain wall needs |
| System Panel : Solid | A solid panel, for cladding you cannot see through |
| Empty System Panel : Empty | A declared empty cell, unlike None in that it still schedules |
| Basic Wall types | Fills the cell with a real piece of wall, for a masonry base or stone cladding |
One thing to know before blaming the software: the Metric template leaves both the Curtain Panel box and all six Mullion Type boxes empty. A wall drawn with M_Exterior Glazing is therefore a bare grid with no glass and no framing. You have to declare them yourself.
Selecting a single panel has a trick to it. Clicking in the middle of a cell selects the whole wall. To get the panel, hover over the cell and press Tab twice, watching the status bar to see what is highlighted. That selection technique is covered in how to copy in Revit.
Panel size is a figure to check before issue. Insulated glass units are best kept under roughly 2.5 square metres each, and a panel schedule shows at once which cells are oversized.
A door in a curtain wall, and Revit louvers
A door in a curtain wall is not an ordinary door family. An ordinary door cuts a hole in a wall and sits in it, but a curtain wall has nothing to cut because it is already an open grid. Try it and the cursor shows the forbidden sign.
The correct method is to swap a panel for a door family made for curtain walls, following Add a Door to a Curtain Wall.
- Hover over the cell, press Tab until the status bar reads Curtain Panels, then click to select it.
- Click the pin icon to unpin that panel.
- Open the Type Selector and pick the curtain wall door family you loaded.
- Adjust the two grid lines either side to the door size, then lock them.
Placing ordinary doors and building door types is covered in how to add doors in Revit.
Louvers go the other way: they are quick to build from the curtain wall system itself.
The common approach for housing starts by duplicating _Not Defined. Set Vertical Grid Layout to Maximum Spacing at the blade spacing, and Horizontal Grid Layout to None. Set Curtain Panel to Empty System Panel : Empty, then set Vertical Mullions Interior Type to a section matching the blade. The mullions become the louvers.
Try it: a glazed elevation and a louver screen
A thirty minute exercise. Work on a model that already has walls and levels.
- Open the ground floor plan and delete about 6000 of front wall.
- Run Wall, type Curtain into the search box and pick M_Exterior Glazing.
- Click Edit Type then Duplicate, and name it
VK-1200-2400. - Set Vertical Grid Layout to Maximum Spacing at 1200, and Horizontal Grid Layout to Fixed Distance at 2400.
- In the same dialog set Curtain Panel to System Panel : Glazed and all six Mullion Type boxes to a rectangular section. Click OK.
- Draw the curtain wall into the gap, setting Base and Top Constraint to two levels rather than an Unconnected Height.
- Select the wall and note the two Number values for Vertical Grid and Horizontal Grid.
- In an elevation, use Curtain Grid with All Segments to add a vertical line making a 900 wide door bay, then lock that line.
- Hover over a cell, press Tab twice until the status bar reads Curtain Panels, select the panel and note Width, Height and Area.
- Duplicate
_Not DefinedasLAM-DUNG-150, set Maximum Spacing to 150 and Curtain Panel to Empty, then draw a louver screen 300 clear of the wall.
Steps 7 and 9 check each other: the panel width must match the spacing, and the panel area must equal the two sides multiplied.
Frequently asked questions
I drew a curtain wall but there is no glass in it. Why?
The Metric template leaves the Curtain Panel box and all six Mullion Type boxes empty, so the wall is a bare grid. Open Edit Type, set Curtain Panel to System Panel : Glazed and fill in the Mullion Type boxes.
Clicking only selects the whole wall, never a panel. What do I do?
Hover over the cell and press Tab. The order at any point is grid line, then wall, then panel. Read the status bar to see what is currently highlighted.
Should I use Fixed Distance or Maximum Spacing?
Maximum Spacing gives a more balanced elevation because every cell matches. Fixed Distance holds the exact spacing but leaves a narrow cell at the far end whenever the length does not divide evenly.
Why did my mullions disappear when I changed the wall type?
Mullions placed by hand belong to the old wall. Changing type rebuilds the grid to the new rule and those mullions go with it. Settle the type first, then place mullions.
Related articles
- How to draw walls in Revit — a curtain wall inherits every wall constraint
- How to add doors in Revit — ordinary doors, quite unlike curtain wall doors
- How to create a Revit family — building your own mullion profile
- How to copy in Revit — selecting with the Tab key and repeating elements