How to create a roof plan with Architect 3D

Written for Architect 3D 26 for Windows. The Mac edition has similar tools, though some menu names differ.

A roof plan is a scaled drawing of a building seen from above, showing each roof plane and what sits on it: vents, chimneys, skylights, dormers. It is one of the drawings usually asked for with a planning or building permit application; exactly what it must show depends on where you build.

Draw the walls of every floor first. The roof is built on them.

Step 1: Choose how to build the roof

All the roof tools are on the Roof tab. Pick the method that fits your floor plan.

Option 1: a predefined roof shape (regular floor plans)

Click the first roof tool on the Roof tab and choose one of the predefined shapes, such as gable or hip, from its drop-down menu. Then drag the roof over the plan.

Option 2: the freehand roof tools (irregular plans)

For an irregular footprint or unusual roof sections, use the Freehand Roof tool and outline the roof shape on the plan. The Four-Point and Three-Point Freehand Roof tools in the same toolset draw a rectangular or triangular section attached to a wall. Every section you draw this way can be edited on its own: pitch, elevation, overhang and shape.

Option 3: the automatic roof (any plan)

1. Move the pointer over the outer walls until the perimeter is highlighted, then click it. It turns yellow and its properties appear on the Properties tab.
2. Click Options to open the automatic roof options. Set the roof pitch (as a ratio or an angle), the soffit depth and the framing settings, then click OK.
3. Click Build Roof.

If the option to generate panels automatically when the walls change is ticked, the roof updates itself when you move or resize the perimeter walls.

Step 2: Roof each floor, then add dormers and skylights

If the building has more than one level, define the roofs for each floor separately: for example the main roof on the upper floor and a porch or single-storey wing on the ground floor.

Then add the details. The Dormer tool adds a dormer with its window to an existing roof plane, Dormer Cutout cuts the matching opening, and the Skylight tool places a roof window directly on a roof panel.

Step 3: Show every roof on one drawing

1. Select the roof elements on the upper floor.
2. On the Edit menu, choose Copy to Floor (Paste to Floor in some earlier versions) and pick the ground floor.
3. View the ground floor: all the roof planes now appear on one plan. That is your roof plan.

Tip: do this step in a copy of your project (File > Save As), so your working model keeps a single set of roofs. Add dimensions and notes with the text and dimension tools before you print.