Roof Instance Properties

Modify instance properties to change an individual roof's work plane, base level, slope, and more.

To change instance properties, select the element and change its properties on the Properties palette.

Name Description
Constraints
Work Plane The work plane with which an extruded roof is associated.
Base Level Sets the level for the footprint or extruded roof.
Room Bounding If selected, it means the roof is part of a room boundary. If not selected, it means the roof is not part of a room boundary. This property is read-only before creating a roof. After you draw the roof, you can select it and then modify this property.
Related to Mass Indicates the element was created from a mass element. This is a read-only value.
Base Offset From Level Sets the height of the roof above or below the level where it is being sketched. This property is enabled only when creating a roof by footprint.
Cutoff Level Specifies a level above which all footprint roof geometry will be not shown. Roofs cut in this manner can be combined with another roof to form Dutch Hip, Mansard, or other roof styles.
Cutoff Offset Height of the cutoff above or below the level specified in Up to Level.
Extrusion Start Sets the start point of the extrusion. For example, if you pick the outer edge of the wall during creation of the extrusion, the start point starts the extrusion to some point traveling out from the outer edge of the wall. This parameter is only enabled for extruded roofs.
Extrusion End Sets the end point of the extrusion. For example, if you pick the outer edge of the wall during creation of the extrusion, the end point ends the extrusion at some point out from the outer edge of the wall. This parameter is only enabled for extruded roofs.
Reference Level The reference level for the roof. The default is the highest level in the project. This parameter is only enabled for extruded roofs.
Level Offset Raises or lowers the roof from the reference level. This parameter is only enabled for extruded roofs.
Construction
Fascia Depth The length of the lines defining the fascia.
Rafter Cut Defines the rafter cut on an eave. See Creating a Plumb Cut, Two-Cut Plumb, or Two-Cut Square Eave.
Rafter or Truss This property is a switch for the Plate Offset from Base property. If you choose Rafter, the Plate Offset from Base is measured from the inside of the wall. If you choose Truss, the Plate Offset from Base is measured from the outside of the wall. To see the effects of this property more clearly, set a value for Plate Offset from Base other than 0. (See Roof Boundary Line Properties.)

This property only affects roofs created by picking walls.

Maximum Ridge Height The maximum height of the top of the roof above the base level of the building. You can set a maximum allowable ridge height using the Max Ridge Height tool. This is a read-only value. This property is enabled only when creating a roof by footprint.
Dimensions
Slope Changes the value of the slope-defining line to the specified value, without the need to edit the sketch. The parameter initially displays a value if there is a slope-defining line. If there is no slope-defining line, the parameter is blank and disabled.
Thickness Indicates the thickness of the roof.

This is typically a read-only value, unless a shape edit has been applied and its type contains a variable layer. When the value is writable, it can be used to set a uniform thickness of the roof. The entry can be blank if the thickness varies.

See Variable Layer Thickness for Roofs and Structural Floors.

Volume The volume of the roof. This is a read-only value.
Area The area of the roof. This is a read-only value.
Identity Data
Comments Comments about a particular roof.
Mark A label applied to a roof. Usually a numeric value. This value must be unique for each roof in a project. Revit issues a warning if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.
Phasing
Phase Created The phase when the roof was created.
Phase Demolished The phase when the roof was demolished.