Table of contents
1. Parametric objects and their importance in the modern building industry
- control parameters – the ones that affect object’s appearance and geometry
- descriptive parameters – the ones that describe the specificity of an object
- classification parameters – the ones that assign an object to a particular product group, according to the particular system classification
2. Object classification-how does it work in the Revit software
- family – a set of elements having the same use, common parameters and similar geometry. They belong to specific categories that cannot be removed from the project, e.g. doors, walls or pipes. There can be multiple families within one category, e.g. double-leaf balcony doors, single-leaf balcony doors or tilt-and-slide balcony doors. In the project there are 3 types of families: system families, loadable families and in-place families.
- type – a subcategory of a family, for example, a single-leaf balcony door can have several different sizes: 865×2095 mm, 865×2295 mm…. Unlike categories, types can be added or removed from a project, based on the user’s preference.
- instance – a single element placed in a project. Each instance has its own properties, but also type-specific properties, that are shared with other instances, e.g. when there is a row of the same door in a wall shown in the open project view.
- library – is a collection of families. Revit includes standard libraries. The custom ones can be downloaded from a specific manufacturer’s website.
The above definitions were based on the Autodesk website. Please, find the link here:
The subject is well-illustrated on the diagram below.
In the next part of the article, the topics of families and libraries are shown from a practical side, based on the experience of experts from the technical installation branch.
3. The process of family creation – interview with an expert and introduction to the process using Revit (interview with Dominik Krzywik – BIM Engineer)
- Let’s start with a short introduction. Who are you? What do you do? What is your experience in BIM? What do you like the most about your job and how does your work contribute to the development of BIM methodology/technology?
- What type of families do you work with and how many families/packages have you made?
- What does the process of Revit family creation look like?
- What do you find to be the most difficult in creating the packages and what challenges does a BIM engineer need to face on a daily basis? Is the game worth the candle?
- What advantages for the users are created with the premade BIM libraries?
The process of creating families itself is quite laborious, therefore using ready-made and, most of all, well-made producer packages allows the users to save time, money, minimize stress and gain certainty that what they work on is reflected in reality. We ourselves avoid many problems e.g. collisions on the construction site caused by implementing generic shapes.
Now I would like to talk about an example from real life. The building was non-standard, and the designer used generic families of bends with an angle of 80° (in general, most of the fittings in the project had non-standard angles). Bends like that do not actually exist, they are not standardized. It was not possible to order such bends, so instead bends with the closest angles to the actual ones were ordered. Such replacement had a huge impact on the installation routes, as it led to collisions with ventilation, walls, etc. At this point, the topic was forwarded to us. To find a way out of the stalemate, we proposed to replace the elements first in the BIM model, this time using our packages/families, and then, on the basis of the model and corrected routes, to recreate the installation on site. It worked, but the problem could have been avoided, if the manufacturer families had been used from the very beginning. Our families do not allow the user to model something that does not exist.
- How can manufacturers contribute to the development of BIM knowledge on the construction market?
4. How do premade families/packages support design workflows? (interview with Adrianna Maćkowska- Technical Designer)
- Just like before, let’s start with a short introduction. Who are you? What do you do? What is your experience in BIM? What do you like the most about your job and how does your work contribute to the development of BIM methodology/technology?
- Which software do you use the most for project making?
- In which projects did you use system packages?
- What poses a challenge and what shall the technical designers pay attention to when working with the premade families/packages?
- How much time (more or less) is it possible to save when using the packages of specific systems compared to making projects with the use of generic objects?
- Do you think that libraries are the future of working with BIM? What are the designers looking forward to when it comes to BIM development? Is BIM really the future of the AEC industry?
There is probably an error on Figure 2. System families are walls, floor…not doors, pipes… 🙂
You are absolutely right! For some reasons the names in the diagram got reversed.
The order should be system for objects that will be erected on the building site, loadable for ready objects that will be delivered to the building site and in-place for the unique objects.
Thanks for spotting the mistake!
i am absolutely agree with the way of modilling objects and we applied it to ceate our own library. At the end this library will have more than 20000 items of pipes, fittings and accessories. To model 10000 items, we need to create only 460 families and only 50 base models. Yes parametrization is very useful!