What is the difference between a System Family and a Loadable Family in Revit?

System Families are built into Revit and exist only within a project file — they include walls, floors, ceilings, roofs, ducts, and pipes. You create new types by duplicating existing ones within the project; you cannot load them from an external file. Loadable Families are external .RFA files created in the Family Editor and loaded into projects via Insert > Load Family. They include doors, windows, furniture, equipment, and most discrete building components. Loadable families can be shared across projects and stored in a firm-wide content library.

When should I use an In-Place family vs. a Loadable family in Revit?

Use an In-Place family for one-of-a-kind custom elements unique to a specific project — a unique reception desk shape, a special architectural reveal, a bespoke built-in. Use a Loadable family for any element that appears more than once, needs to be scheduled by quantity, or will be reused on other projects. In-Place families cannot be copied to other projects and do not schedule well, so overusing them creates performance and documentation problems.

What is the difference between Type Parameters and Instance Parameters in a Revit family?

Type Parameters are shared by all instances of a family type — changing a type parameter on one element changes every element of that type in the entire project. Instance Parameters belong to a single placed element and can vary per placement. Use Type Parameters for properties that define a product model (door width, beam depth, pump flow rate). Use Instance Parameters for properties that vary by location (sill height, mark number, installed elevation). Mixing these up is the most common family authoring mistake.

What Revit family template should I use for a ceiling-mounted light fixture?

Use the Lighting Fixture face-based template (Lighting Fixture.rft) or the ceiling-hosted lighting fixture template depending on whether the fixture will always mount to ceilings specifically or might also mount to walls or sloped surfaces. For recessed troffers that always go in ceilings, ceiling-hosted is preferred. For surface-mounted fixtures that might go on walls or ceilings, face-based gives more flexibility. Always verify the family category is set to Lighting Fixtures so it appears in light fixture schedules.

How do I load a Revit family into a project?

Go to Insert > Load Family. Navigate to the .RFA file in your firm's content library or Autodesk's default library location (C:\ProgramData\Autodesk\RVT [year]\Libraries on Windows). Select the file and click Open. If the family contains multiple types, a dialog asks which types to load — you can load all or select specific types. The family then appears in the Project Browser under Families and is available to place from the appropriate tool (Architecture > Component for model families, or Systems tabs for MEP families).

Why is my Revit family not appearing in schedules?

The most common cause is an incorrect family category. Open the family in the Family Editor (select an instance, click Edit Family), go to Create > Family Category and Parameters, and verify the category matches the schedule type — doors must be in the Doors category to appear in Door Schedules, mechanical equipment must be in Mechanical Equipment to appear in a Mechanical Equipment Schedule. Also verify that the parameters you want to schedule are shared parameters defined in the project's shared parameter file, not just local family parameters.

Design·11 min read·June 19, 2026

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Every piece of building content in Revit — every wall, door, structural beam, light fixture, and custom millwork piece — belongs to one of three family types. Understanding the distinction is not academic; it determines what you can modify, how the element behaves in schedules and views, and what happens when you need to change the design. Choosing the wrong family type for a task is one of the most common sources of bloated, inflexible Revit models.

Topics covered

Revit families explainedRevit system familiesRevit loadable familiesRevit in-place familiesRevit RFA fileRevit family editorRevit type parameters instance parametersRevit family hostingRevit family templateRevit family categoriesRevit parametric familiesBIM content creation