21 January 2021
Hierarchy of Revit Family Creation
Just as every great building begins with a single brick or plank, designing with Revit begins with a Revit family. Revit family creation is a specialised multi-layered field of expertise in design modelling and drafting.
The usefulness of Revit family creation lies in its ability to create uniformity, accurate sizing and depict aesthetics that are precise, while using small models to create larger, more complex ones. Understanding the hierarchy of Revit family modelling and Revit family creation thus becomes a significant factor in effectively creating Revit models.
Hierarchy of Revit Family Creation Infographic
1. Revit Element
Every object or unit in Revit is an element. The Revit family hierarchy begins with the Category, followed by the Family, then Type and finally Instance.
What is a Category in Revit?
A category is a broad grouping of elements. A category directs the organisation, visibility, graphical representations and scheduling options of families of elements within a project. For example:
- Door Category – used to create different kind of doors.
- Column Category – used to create columns, eg. Wide-flanged, precast, angled, etc.
What is a Family?
Within a category, a Revit family is a group of elements with a common set of properties, or parameters, represented graphically. Every element in Revit is created using families. Eg. Within the door category, we have single door family, double door family.
Three Kinds of Revit Families
- System families are preinstalled families for basic elements (eg. walls, roofs, ducts, pipes, etc.) which are neither loaded from nor saved in external files. Their settings include types for levels, grids and drawing sheets.
- Loadable families are created elsewhere and uploaded into the project and are used to create doors, windows, fixtures, furniture, plants, etc. that are bought, transported or fixed in and around a building.
- In-place families are created within the project environment to customise elements solely for the individual project and cannot be used for other projects. They are developed with a specific geometry that can be modified.
What is a Type?
A type of family, or family type, is a specific representation in a family defined by distinct parametric, graphical and documentation characteristics, unique from other family types. Eg. Within the single door family, we have single doors with different parameters: 36 X 84 full vision, 36 X 90 vision panel.
What is an Instance?
An element created using a particular family and a specific family type is known as an instance. An instance is unique, with unique properties. Instance parameters can be modified without changing family type parameters. Eg. Within the single door ‘36 X 84 vision panel type’, we have a unique door without a vision panel.
2. Revit Family Creation Workflow
3. Is Outsourcing Revit Family Creation a Better Option?
Experts with sound experience and knowledge can create error-free Revit families. Investing in the latest technology regularly may be costly for some firms and may need them to recruit, train and retain qualified personnel. Outsourced organisations can deliver high quality on time at lower costs, resulting in greater profitability.
XS CAD, a UK/India-based firm, has several years of experience in family creation for architecture and building engineering.
XS CAD has valuable experience providing architectural design services and architectural design drafting services for commercial, mixed-use and healthcare industry. Our range of services for building design firms across the world include architectural BIM modelling and other architectural BIM services and we offer retained teams when required. We create these models, drawings and renderings by using Revit, AutoCAD, Illustrator and BIM 360 Design for cloud collaboration.