Project Phases & Phased Design

Project Phases & Phased Design


Many projects, whether new construction orrenovations,are designed and constructed in distinct phases. These phases can represent either the time periods themselves or the state of the project at specific points in time.

In this lesson, you explore two applications of project phases and phased design:

  • Using project phases to organize the information in a building model based on the project phases during which different portions will be constructed.
  • Using project phases to coordinate the elements in a renovation project and display accurate views of the as-built conditions, demolition work, and proposed new design.

By defining project phases and using phase-based filters to determine the information presented in model views, the building modelcan be used to facilitate design and visualization at each of the stages in the project life-cycle.

Modeling Phased Projects in Revit

Phases are distinct, separate time periods or “milestones” within a project. Every project includes at least one phase, and by default, Revitsoftware defines two phases (named Existing and New Construction) in new projects. The project team can rename these phases or add as many phases as needed to accurately describe the project.

All elements in the building model have two properties that control the time periods during which the element is considered to be present—Phase Created and Phase Demolished. In project phases before the Phase Created or after the Phase Demolished, the element is ignored and will not be displayed in model views.

The visibility of model elements is any view is determined by a combination of the Phase property for that view and a Phase Filter that determines how elements will be displayed based on their creation and demolition state relative to the current phase. Every element is assigned a status relative to the phase of the current view:

  • New—if the element was created in the phase of the current view.
  • Existing—if the element was created in an earlier phase and continues to exist in the current phase.
  • Demolished—if the element was created in an earlier phase and demolished in the current phase.
  • Temporary—if the element was created and demolished during the current phase.

Phase filters control the appearance of elements based this phase-based status by specifying how elements of each status should be displayed:

  • By Category - The display settings in Visibility and graphics for that view will be used to display any objects in that Phase Status.
  • Not Displayed – Any object that is that Phase Status will not display in the view
  • Overridden – Any object that is that Phase Status will use the Graphic override that is set on the Graphic Overrides tab of the Phases dialog.

This phase information and phase filters are commonly used to create phase-specific views of the building model that present or hide the model elements in a way that is most appropriate for that project phase. The following table illustrates one scheme for using phases and phase filters to create views for specific project uses.

View Phase
Phase Filter
Used for:
Phase 1
Show Previous + New
Anything created before Phase 1 Items created in Phase 1
Anything demolished in Phase 1 Any temporary items created and demolished in Phase 1
Views of proposed design at end of Phase 1
Phase 2
Show Previous + New
Anything created before Phase 2 Items created in Phase 2
Anything demolished in Phase 2 Any temporary items created and demolished in Phase 2
Views of proposed design at end of Phase 2
Phase 2
Show Previous + Demo
Anything created before Phase 2 Objects demolished in Phase 2
Objects created in Phase 2
Views showing demolition between Phases 1 and 2
Phase 2
Show New
Only items created in Phase 2
Anything created before Phase 2
Views showing new elements added in Phase 2

Phased New Construction

Many projects consisting of several buildings are designed and constructed using a phased process that divides the work into manageable packages based on the planned construction sequence.  For these projects, it is often useful to assign the building model elements to distinct phases, so views can be filtered to show the elements relevant to a specific phase.

By setting the phase property and phase filters for each model view and schedule, we can control the appearance of building model information and create phase-specific project documentation. This approach simplifies the management of complex building models and assists in the preparation of construction documents by allowing designers to focus on a single phase at a time.

Phased Renovations

Another common design situation is which project phasing can be very useful is renovations or retrofits of an existing structures. Renovations are typically modeled using two phases:

  • Existing—which is used to model the existing as-built conditions.
  • New Construction—which is used to model the proposed design.

Demolition is typically not modeled as a separate phase.  Rather, it is better practice to indicate the building elements to be demolished by setting the Phase Demolished property for these elements to the New Construction phase. Demolition plans can then be created by using a phase filter to display and highlight the elements to be demolished.

An important consideration to keep in mind while modeling renovation projects is that building elements can only be created or demolished between phases. When only a portion of a building element should be demolished, it is often helpful to split that element into individual parts, so that each segment can be treated separately.

Building elements created in prior phases should not be edited, stretched, reshaped, or deleted, because these operations will change their appearance in all phases. This limitation mirrors the physical reality of how objects can change between phases—you can typically create new objects and demolish existing ones, but physical elements typically cannot be stretched to a new configuration.

Learning Objectives

After completing this lesson, you will be able to:

  • Appreciate the importance of deciding in early stages how many phases they need, what to name them, and how to order them
  • Appreciate the method of setting up individual views to showonly the desired phases and to generate temporal snapshots of the project.
  • Understand how to attribute phases properties –phase created and phase demolished – to objects and to attribute phase and phase filters to views
  • Explore how to model elements in the correct phase filtered view to correspond with the phase you are editing or adding to.
  • Appreciate techniques of modeling that accurately represent, in the practical construction terms, how they change through the project.


Phased New Construction

In this exercise, you will learn how to:

  • Enable phases and define the necessary phases for a given project.
  • Set up phase-specific views with phase filters applied in order to accurately represent the state of project at any given time.
  • Assign phase properties of model elements to properly represent when each structure will be built relative to the others.
  • Adjust graphics overrides for phase filters to display as desired.

Figure 2.2.1. Setting the phase filter to Show Previous+ New model elements

Video Tutorial

Student Exercise

  • Add another phase to the project and name it Phase 3.
  • Duplicate the existing views (plan views, elevations, and 3D views) of Phase 2 to create two sets of new views for Phase 3, setting the Phase and Phase Filter properties to show these states:
    • Phase 3 Planning: use the Previous + New phase filter to override elements from previous phases and display them in grey.
    • Phase 3 Complete: use the Show Complete phase filter to display elements from all three phases by category.
  • Open the new Phase 3 views and place building elements (walls, doors, windows, roofs, and so on) to construct the envelope of a third building in the space indicated.
  • Open the views for the prior phases and verify that your new building elements appear only in the views for Phase 3.

Figure 2.2.2.Adding a new phase to the project

Phased Renovations

In this exercise, you will learn how to:

  • Set up the phase-specific views in order to model construction for a renovation or remodel.
  • Perform the demolition operations on model elements to make way for the elements in the new construction.
  • Create model elements that have correctly defined phase parameters.

Figure 2.2.3. New elements placed in kitchen during renovation phase

Video Tutorial

Student Exercise

  • Open the proposed plan view of the home remodel, and demolish the building elements located in the bedroom wing of the residence.
  • Place elements (walls, doors, windows, roofs, and so on) in the project model to illustrate a proposed design for the bedroom suite addition.
  • As you place new elements, be certain not to delete, stretch, or edit existing building elements. To accurately model a renovation project, elements should only be demolished or created.
  • Place the floor plan views and elevations showing each of the project states (as built, demolition, and proposed) on D-size 24x36 (0.61 m x 0.91 m) sheets, cropping and scaling the views as needed to fit on the sheets.
    • Place all of the four elevations on one sheet.
    • Place the floor plan on a separate sheet.

Figure 2.2.4 -Example of proposed design for bedroom suite renovation during second project phase


Phased New Construction

  • Would it be appropriate to create a separate phase named Demolition?

While it is possible to create a separate project phase named Demolition, it is typically unnecessary and confusing to isolate this step. Rather, demolition is typically shown by setting up a phase filter that highlights the elements demolished during a phase. Typically, demolition is a very quick process, but if detailed planning of the demolition phase is needed a separate project phase can be defined.

  • Why do room objects exist in a single phase and not span between phases?

The properties of rooms (for example, the type and occupancy), as well as the boundaries, often change between project phases. So, rooms must be defined explicitly during each project phase to avoid ambiguity or confusion.

  • Which settings determine whether an element will be displayed in a view in a phased project?

Whether an object is displayed depends on both the properties of the element and the view. For each element the phase created and phased demolished properties determine the existence of the element in any given phase. For each view, the combination of the phase and phase filter properties determines which elements are candidates to be shown. Finally, the graphic overrides determine which of the candidates will be displayed based on each element’s model category.

Phased Renovations

  • How can you demolish a portion of an existing wall or building element?

If an element can be split, you can break the single element into parts—the part to keep and the part to demolish. Once split, you can demolish the appropriate part.

  • What happens when we demolish a hosted object, such as a door or window?

When you demolish a hosted object, such as a door or window, Revit automatically fills in the opening that was created to host that object. This models real world behavior. Demolishing a window, for example, typically involves patching the opening with the adjacent wall materials.

  • How could you apply phases to schedules, which are essentially just another model view?

For example, in a large renovation project, a door schedule would usually list all doors created in the project. In a building with hundreds of doors, the schedule could become difficult to work with, because the demolished doors would be listed with the post-renovation doors. It’s typically better to create separate pre-demolition and post-renovation schedules by applying the appropriate phase and phase filters to each.

Key Terms

Key Term
Project phase
A distinct time period in the life of the project.
Phase filter
A phase filter is a rule that you apply to a view to control the display of elements based on their phase status. Filters can specify that elements be displayed by category, overridden, or not shown.
Graphic override
A rule that specifies howoverridden elements be displayed based on their phase status.
Phase status
The status of each building element relative to the phase specified for the current view. Each phase status typically has a different display style associated with it to make it easy to identify the phase status of the elements in a view.
The phase status assigned to elements that were created in an earlier phase and continues to exist in the current phase.
The phase status assigned to elements that were created in an earlier phase and demolished in the current phase.
The phase status assigned to elements that were created in the phase of the current view.
The phase status assigned to elements that were created and demolished during the current phase.