Vaults
Click two corners of a room and a vault springs from its walls. A barrel arcs across the room; a groin is two barrels crossing; a cloister rises from all four sides. Set its rise, its thickness and what it is cast or laid in.
Three vaults
Each built by the editor over a room. Switch between them, and between the 3D model and the plan, in the bar above.

Barrel vault
An arc extruded along the room. Masonry, 1200 mm rise.

Groin vault
Two barrels crossing, the higher of the two. Masonry, 1300 mm rise.

Cloister vault
Rising from all four walls, the lower of two barrels. Concrete, 1300 mm rise.
Every property, and what it does
Select a vault and these are its rows.
Vault
The vault's form, size and material.
| Field | What it does | Values |
|---|---|---|
| Form | A barrel is an arc extruded along its length; a groin vault is the higher of two barrels crossing, a cloister vault the lower. | Barrel vault, Groin vault, Cloister vault |
| Rise | How high the crown stands above the springing. Half the span is a semicircle. | Millimetres |
| Thickness | The shell's thickness. A barrel's is the arc's own; a vault carries it vertically. | Millimetres |
| Spans across | Which way a barrel arcs. Left unset, it arcs across the shorter side. | X, Y |
| Made of | What the shell is cast or laid in. | Concrete, Masonry, Timber |
Where it springs
The height the curve starts from.
| Field | What it does | Values |
|---|---|---|
| Springs at | Where it springs, above the storey's floor. Clear it to spring from the wall head. | Millimetres, or the wall head |
Derived
Read from the vault as it is.
| Field | What it does | Values |
|---|---|---|
| Span x length | The vault's span and length. | Metres |
| Springs and crowns at | Both heights, above the plan's datum. | Metres |
| Covered area | The area under the vault. | Square metres |
| Volume | The volume of the shell. | Cubic metres |
How the Shell tool works
Open the Shell tool
In the editor, open Build and choose Shell, or type SHELL (VAULT).
Click two corners
Click two opposite corners of the rectangle the vault covers. It springs from the storey's wall head as a barrel.
Choose its form
Its panel makes it a groin or a cloister vault, and sets which way a barrel spans.
Size it
Set its rise, its thickness, where it springs and what it is made of.
Vault questions, answered.
Which vaults can I build?
Barrel vaults, groin vaults where two barrels cross, and cloister vaults rising from all four sides.
How high does a vault rise?
As high as its Rise says, above the springing. A rise of half the span makes a semicircular barrel.
Where does a vault start?
From the wall head by default. Springs at can set its own height above the floor.
Read on
- Roofs docs: Hipped, gabled, shed and flat roofs.
- Wall Design: The walls a vault springs from.
- Columns: Classical, timber, steel and masonry columns.