Phasing: Roof Demolition

Revit’s built-in Phasing capabilities are quite easy to understand, especially if one remembers that phasing works according to a timeline. Whatever happened in the past, is existing, and whatever will happen in the future, will be a new construction. The example we will use will be of an existing building with the addition of a new entrance area.

The building already exists, so we need to select all geometry and change its phase to Existing

I have made a few changes to the graphic override filters for the projects phases, to make the New Construction phase’s Cut- and Projection lines thicker, and the Existing phase’s line colour lighter. The Demolished phase has also been changed to Red Dashed lines with a light red solid fill.  Typically one would have a separate view for the Existing phase and another separate view for the new construction phase, but for the purpose of this exercise, I will change the current view’s phase to new construction. When the new entrance area walls are drawn, it will adopt the phase of the current view (Thus, new construction).

Demolishing a portion of roof is quite different to the methodology of demolishing any other element in Revit. We will need an existing roof structure, a new roof structure, as well as an exact match to the portion of roof to be demolished. We will go through the latter steps below.

When we create the new entrance area roof, we will need to join the two roofs together via the Join/Unjoin Roof command, found in the Modify tab, Geometry Panel, Join/Unjoin Roof command.

In order for this roof demolition method to work correctly, as well as be graphically represented on plan in the correct way, we need to edit the existing roof’s boundary, to exclude the roof portion that should be demolished.

The roof portion that needs to be demolished should be drawn as a separate roof. Once the roof has been created, the Phase Created parameter must be set to Existing, and the Phase Demolished, to New Construction.

The images below shows what one will see in a wireframe mode.

We will demolish the section of wall in the new entrance area by using the Split Elements command, and setting the demolished wall’s Phase Demolished to New Construction.

The images below will indicate what building elements will be seen at which Phase Filter Status.