Creating sloping roofs How to create gable, cross-gabled, dormer, hip and other complex sloped roofs with slabs Amritha Krishnan

Sloping roofs can be created using the Draw tool to draw the footprint of each face and editing it to create the slope. Simple sloping roofs are created by splitting a roof face and editing it. Complex sloped roofs are created in sections, each section representing a unidirectional slope.

Creating a simple gable roof

In plan or 3D view, draw the footprint of the gable. Select the mass, and in Object Properties, change the type to Slab. A slab is created with 150mm thickness.

Use the Split Face tool to split the top face of the slab. Hover along the width of the slab to locate its midpoint. Click to start the split. Hover along the opposite width to locate the midpoint and click to place the split line.

Using the Move tool, double click on the splitting edge and move it up by the required roof height. You can repeat the same with the bottom face to create a sloping soffit, or leave it as it is for a solid soffit.

Creating a gable roof in editable sections

Open the plan view of the Storey you want to create the roof on. Draw the footprint of the gable. Select the mass, and in Object Properties, change the type to Slab. Using the Move tool, double click one of the long edges of the footprint to reduce the width to half. Create a copy of the slab and place the two slabs end to end along the width. Flip one of the copies along the axis parallel to the slab length.

Go to 3D view. Using the Move tool, double click one of the top long edges and move it up by the required height to create the slope. Both copies are edited. Move the corresponding bottom edge by the same distance to create sloping soffit.

The gable roof is created. You can move the front and back faces of either slab to increase gable extents.

Adjusting overhangs on sloping roofs

To increase or decrease overhang of the sloping roof, use the Move tool and double click on the eave face. You can move the face outward or in to change the overhang distance from the wall. Corresponding copies of the sloped slab are also updated.

Ridges and valleys of a cross-gabled roof

Start by creating two gables perpendicular to each other (or at any other angle to each other). Use the Move tool to double click and move the vertical face of one of the gables. Use the snap indicators to extend the gable upto the intersection of the two gables. Repeat this with the other gable.

Select the 4 parts of the cross-gable, and in Object Properties, click on Make Unique. Now you can edit each component independently, without affecting the others. Use the Move tool to double click and align the edges.

Typical intersections and dormer roofs

Create each component of the roof like a standard gable roof, and align the dormer components along the long edge of the primary gable. Double click and Move the top vertical edge of the dormer to the gable. A snap indicator is displayed when the dormer edge intersects the gable edge. The dormer is created.

You can further move the eave face of the dormer in or move the eave face of the primary gable out.

Creating a hipped roof

Create a standard gable roof and edit it in plan to create a triangular space for the hip component. Draw the hip component and tag it as a slab. In 3D, move the vertical edge of the slab (or the 2 vertices) and snap to the gable edge. The hipped face is created.

Did this answer your question?