Learning how to create a roof in Revit trips up most beginners, though not because the command is hard. Drawing a roof is almost identical to drawing a floor.
The difficulty is that you do not set the roof form directly. You declare two things only: the outline, and which edges of it slope. Revit works out the ridges, the valleys and the apex. Clear the slope mark on one edge and the whole form changes, including places far from that edge.
So the method runs against hand-drawing habits: do not draw the shape you want and describe it back. Declare the outline and the slopes correctly, then check the result in a 3D view.
This article works through Chapter 9 of the Institute's textbook Autodesk Revit 2027 for Architectural Documentation, ordered the way you actually work so you can follow along. Screenshots come from Revit 2027, English interface. To learn the documentation stage in full, see the Revit Architecture course.
Five steps to build a pitched roof
The next four sections set out how to create a roof in Revit in the order you click. The Roof button sits on the Architecture tab, Build panel. Its drop-down holds six items in two groups: three ways to build a roof above, three roof details below.
| Item | What it does |
|---|---|
| Roof by Footprint | Sketch the outline in plan, then set the slope per edge. This covers nine roofs in ten |
| Roof by Extrusion | Draw the roof profile in elevation and extrude it. For curved and vaulted roofs |
| Roof by Face | A roof taking the face of a mass |
| Roof: Soffit | The underside panel of an overhanging roof |
| Roof: Fascia | A fascia running along a roof edge |
| Roof: Gutter | A gutter running along a roof edge |
Autodesk documents the first method on its Create a Roof by Footprint page. What follows works that way.
Step 1 — set the slope unit before anything else
Do this first, because it affects every slope figure in the file. Revit reports slope in degrees, while many offices work in per cent or in ratios.
Go to Manage › Project Units.
| No. | Part | What it does |
|---|---|---|
| 1 | The Discipline field | Set to Common. Each discipline keeps its own units, and everything architectural lives in this group |
| 2 | The Slope row | Reading 12.35 degrees, so slope is currently in degrees. Click the Format cell on this row |
| No. | Part | What it does |
|---|---|---|
| 1 | The Units field | Currently Degrees. This is the one to change |
| 2 | The Rounding field | Decimal places. Two is more than a roof slope needs; one is enough |
The Units list offers more than ten formats. Three see real use: Percentage for flat roofs and gutters, 1 : Ratio for steep pitches, and Rise / 1000 millimeters for site work. Once changed, every slope figure in the file converts at once, including labels already placed.
Steps 2 to 5 — sketch the outline, set the slopes, then check
Called from the lowest level, Roof by Footprint asks a question before letting you draw.
It asks whether to move the roof up to another level. The answer is almost always Yes, since a roof at ground level is meaningless. The ribbon then switches to outline sketch mode.
| Panel | What it does |
|---|---|
| Mode | The red cross cancels, the green tick finishes |
| Draw | Boundary Line, Slope Arrow, the geometry gallery and the Pick Lines, Pick Walls buttons |
| Slope | One button, Define Slope — it decides whether the edge you draw carries a slope |
| Create Roof | Extend Into Wall and Overhang, the projection beyond the wall |
| Work Plane | Rarely needed for a footprint roof |
| Tools | Align Eaves levels the eaves. The other two light up once an edge is selected |
Set Overhang first, then click Pick Walls and select the perimeter walls. Define Slope is on by default, so every edge you create carries a slope.
| No. | Part | What it does |
|---|---|---|
| 1 | The triangle mark | Wherever it appears, that edge carries a slope |
| 2 | The slope angle | The selected edge also reports its angle. The default is 36.87 degrees |
That 36.87 is not arbitrary: it is the imperial 9 in 12 pitch. Change it on your first roof.
The next step decides the roof form, and it is where the surprises happen.
The reason lies in how Revit solves it: it does not assemble the sloping faces one by one, but solves the whole outline at once. Clear the slope on the two gable ends and four surfaces become two, meeting along one straight ridge.
Select an outline edge and look at its own Properties.
| No. | Part | What it does |
|---|---|---|
| 1 | Defines Roof Slope | The checkbox deciding whether this edge slopes. The 2027 release puts it here rather than on the Options Bar |
| 2 | Slope | The angle for this edge alone. Change it here per edge, not for the whole roof |
The palette also holds Overhang for this edge, Plate Offset From Base, and Extend into wall. Click the green tick, then select the finished roof.
| No. | Part | What it does |
|---|---|---|
| 1 | Constraints | Base Level is the eaves level. Leave Cutoff Level as None; setting one truncates the roof above it, which suits dormers |
| 2 | Construction | Rafter Cut controls how the eaves are cut. Maximum Ridge Height is greyed out because Revit derives it — read it when the building has a height limit |
| 3 | Dimensions | Slope and Thickness. Slope shows a figure only when every sloping edge shares one angle |
To change the slope combination after the roof exists, select it and click Edit Footprint, then toggle Defines Roof Slope per edge. There is no need to delete and start again.
Layer build-up and tile materials
A Generic roof has no material, so a section shows only two plain lines. The build-up is defined in Edit Assembly, opened from the Structure row of Type Properties.
| No. | Part | What it does |
|---|---|---|
| 1 | Summary row | Total thickness 225.0, marked Default. The thermal figures read zero because the Structure layer has no real material yet |
| 2 | The layer table | Six columns: Function, Priority, Material, Thickness, Wraps and Variable |
The Variable column matters for flat roofs: with it, the roof can take falls from the shape editing tools exactly as a floor does.
Materials go in the Material column. Each material carries two patterns, and mixing them up is a very common mistake.
A tiled roof build-up here usually runs to four layers: tiles, battens, counter-battens and a reinforced concrete slab. Keep a few such types in the office template.
| No. | Part | What it is |
|---|---|---|
| 1 | The tiled surface | A material carrying a tile pattern, visible at Fine detail |
| 2 | Purlins and fascia | The timbers under the eaves. They are separate elements, modelled as beams or in-place components |
| 3 | Gable and mouldings | Built with Wall: Sweep |
One note from practice: this sample roof was built with the Floor command, not Roof — a very common habit locally. Revit allows it and quantities still schedule, but the element belongs to Floors.
Curved, flat and glazed roofs
Curved and vaulted roofs cannot be described by an outline and an angle. You draw the roof profile itself and let Revit extrude it, using Roof by Extrusion. That needs a vertical plane to draw on, so Revit asks for a work plane first.
| No. | Part | What it does |
|---|---|---|
| 1 | Current Work Plane | Name reads none and the buttons below are greyed — no plane has been chosen |
| 2 | Specify a new Work Plane | Three routes: pick by name, pick an existing plane, or pick a line and use the plane it was sketched in |
The sequence runs to five steps:
- Draw a reference plane at the gable and give it a name.
- Open an elevation or section that sees that plane.
- Run Roof by Extrusion and choose the named plane in the Work Plane dialog.
- Draw a curve or a chain of lines describing the roof profile — it need not close.
- Finish, then adjust both extrusion ends with the arrows or through Extrusion Start and Extrusion End.
A roof built this way has no slope constraint, so to reshape it click Edit Profile.
Flat roofs are rarely flat: they carry a fall of one to two per cent to the outlets. That is far too small to declare as an edge slope. The correct method is five steps:
- Duplicate the roof type, open Edit Assembly and tick the Variable column for the top layer.
- Pick the walls for the outline, turn off Define Slope on all four edges, and finish.
- Select the roof, click Add Point on the Shape Editing panel and click at the outlet.
- Click Modify Sub Elements, select that point, type a negative height and press Enter.
- Check in section that the top surface really falls towards the outlet.
Build a perimeter gutter as a separate dropped panel 300 to 500 wide, and a parapet as a low wall 300 to 600 high with Base Constraint at roof level. Do not carve the gutter out of the main slab — quantities come out wrong.
Glazed roofs have no command of their own, because one really is a gridded frame like a curtain wall. Three routes: draw a curtain wall and set Cross-Section to Slanted; build a Generic roof and apply a Curtain System to its top face; or pick a type from the Sloped Glazing family while drawing. The last is quickest — type Sloped into the Type Selector search.
Attaching walls, fascias and gutters
How high a gable wall is built is decided by the roof. Drawing walls to equal height and trimming them by hand is two-dimensional thinking.
| Item | What it does |
|---|---|
| Attach Top | Attaches the wall top to an element above. Click the button, then click the roof |
| Detach Top/Base | Releases the constraint and returns the wall to its Properties height |
| Wall Opening | Cuts a rectangular opening in a wall |
Select one or several walls, click Attach Top, then click the roof. The tops cut to the underside at once, however it slopes. Afterwards Top is Attached switches on and Unconnected Height greys out — which is why typing a height into it does nothing.
The last three Roof menu items all sweep a profile along a chosen edge: Fascia is the fascia board, Gutter the gutter, Soffit the underside panel. Placing one runs to five steps:
- Run Roof: Fascia or Roof: Gutter.
- Pick a type in the Type Selector, or duplicate one and change its Profile.
- Click each roof edge in turn. Revit joins consecutive runs and mitres the corners.
- Click Restart Fascia to begin a new run that does not join the previous one.
- Check the mitres in 3D, and the profile on a section through the eaves.
The two fields used most are Vertical Profile Offset and Horizontal Profile Offset, because a gutter almost never sits exactly on the roof edge.
The shape of a fascia or gutter cannot be changed by a number: the whole type has a single field that decides its form, Profile. For a U-shaped gutter you build a profile family and select it there.
Try it: build a pitched roof in ten steps
The exercise comes from Chapter 9 of the textbook.
- Open Manage › Project Units and switch the Slope Format to per cent. Note the default slope figure afterwards.
- Open the attic floor plan. Run Architecture › Roof › Roof by Footprint.
- In the Lowest Level Notice, choose the roof level and click Yes.
- Set Overhang to 600 on the Create Roof panel, click Pick Walls and select the four perimeter walls.
- Select the two gable edges and clear Defines Roof Slope. Watch the triangle marks disappear.
- Select the other two edges and set the slope to 30 per cent. Click the green tick.
- Open a 3D view: is it a gable roof or a hip roof, and why?
- Select the roof, note Maximum Ridge Height and compare it with the height allowed.
- Duplicate the roof type as
M-NGOI-150, add a Finish 1 layer 20 thick with a tile material, and give that material a Surface Pattern. - Select the attic walls, click Attach Top and click the roof. Check Top is Attached on one wall.
Then add the roof details using the five steps above: a Fascia-Flat 19 x 286mm on the four lower edges with Vertical Profile Offset at minus 50, and a gutter along the two low edges.
Three common problems
These three turn up on almost every first project, and none is a software fault — all three are settings.
| Problem | Cause and fix |
|---|---|
| The plan does not show the whole roof | The roof sits above the view's cut plane and is trimmed away. This is a View Range matter; the quick answer is a dedicated roof plan |
| Slope units are not what you wanted | Revit reports slope in degrees. Change it at Manage › Project Units › Slope, as in step 1 |
| The roof does not close against the walls | Walls built to equal height either poke through the roof or fall short. Fix it with Attach Top, not by editing each wall's height |
Frequently asked questions
Why does clearing one edge change the whole roof?
Because Revit solves the form for the entire outline at once rather than assembling faces. The combination of sloping edges decides the roof type, not any single edge.
What differs between a tiled roof and a metal-sheet roof?
The form is built the same way. What differs is the layer build-up and the material on the top layer. To see tile courses on an elevation, edit the material's Surface Pattern, not its Cut Pattern.
Does a flat roof need an edge slope?
No. A one to two per cent fall is far too small to declare at the outline. Build it flat, then add falls with Add Point and Modify Sub Elements, provided the type has a layer with Variable ticked.
Changing the height of an attached wall does nothing. Why?
Once a wall is attached, Unconnected Height has no effect. Click Detach Top/Base first, change the height, then attach it again.
Related articles
- How to draw stairs in Revit — the next element in the set
- How to create a Revit family — build your own gutter profile
- Export Revit drawings to CAD and PDF — take the roof plan into the set
- A Revit learning path for beginners — the order to learn elements in