BIM AND THE MATERIALITY OF BUILDINGS
In a previous blogpost called BIM Breakthrough, we highlighted the significance of Archicad’s Priority-Based Connection (PBC) and felt it was a breakthrough because materials recognized one another’s priority, which also dictates how they interact. In this blogpost, we want to explore some ways in which the PBC can be taken to a level that could truly open a broader range of BIM possibilities.
It is our contention that materials are vital to buildings and that architecture cannot authoritatively exist outside the realm and construct of materials. Therefore, for BIM to deliver fully on its potential, its makers must focus on the materiality of building components. If that premise and thesis are accepted, then greater effort can be invested by BIM companies to explore the materiality of buildings in the context of the virtual world of BIM.
More often than not, the materials in many BIM programs are no more than parametric objects with metadata about material type, thickness, density, permeability, etc. While one can argue that the metadata makes the parametric walls intelligent, that intelligence is limited because it does not go the heart of how the walls should behave and interact with each other to make the architect’s life much easier, which is our central metric for using BIM.
So here is an example of what we mean by materiality of building components. Supposed you have an office building with a 2-hour fire-rated corridor in the middle leading to an egress at each end. Once the zone, the principal repository of all metadata related to the corridor, is designated as 2-hour fire-rated, then the BIM program should recognize that the walls on either side of the corridor should be 2-hour fire-rated and behave accordingly. This means that there would be sufficient intelligence in the walls to recognize the fire rating of the corridor zone and alert the architect if there is a mismatch between the two. In fact, it would be great if the BIM program’s database could include Underwriters Laboratory (UL) fire-rated walls that the architect can choose from. Of course, a BIM program like Solibri can flag a non-compliant fire-rated wall, but a better way would be for the BIM authoring tool to do it before a design is fully committed.
Next, all doors on the fire-rated walls would be sufficiently intelligent to pick up their corresponding fire rating (1.5 hour) and that if the fire rating of the walls changes, so will the fire rating of the doors. This means that architects will no longer have to fill in the door fire ratings on a schedule.
The second example relates to room finish schedules. Say a given room in that office building has three internal walls made out of metal stud and gypsum wall board and an exterior glazed wall. The BIM program should be smart enough to recognize that, based on some criteria that the architect can establish with building materials. In the room finish schedule, the three internal walls will be shown as painted as a default, and the exterior glazed wall will show no finish. If a wall has wood paneling, the program should be smart enough to say so in the room finish schedule. This means all interior walls that are exposed and visible within a zone should be given a default finish based on their materials and certain criteria that the architect can override where necessary. If the interior material and finish of a wall change, the change will automatically be reflected on the room finish schedule. This would make the architect’s life much easier when it comes to making room finish schedules. Can you imagine if we could practice architecture and knowing that the BIM program will take care of all our room finish schedule and all we have to do is just check the result?
Archicad’s PBC was a breakthrough that many BIM programs are still slow to emulate. However, the two examples above show what the next step might be to make materials more intelligent and get zones and walls that contain them to intelligently communicate among them without the architect serving as a communication relay. This also means that zones should be much more intelligent to recognize the materials and finishes that surround them and define their functional character and spatial meaning.