What are the principal advantages of using a single building information model of the existing conditions as the foundation for modeling proposed additions or renovations?
- Why not create a separate model for the new proposed design?Using a single BIM model of the existing conditions as the base for new additions or renovations keeps everything accurate, coordinated, and much easier to manage. When you build on top of the existing model instead of starting fresh, all the geometry, levels, and reference points line up perfectly. Also, it saves a lot of time from having to redo modeling work that has already been completed (e.g. I’m really happy I didn’t need to start from a fresh template for this assignment).
Working from an existing model also means you can immediately see how new systems interact with what’s already there (structure, HVAC, MEP, etc). Updates to the existing model automatically carry through, so you’re always working from the latest version. Having it all in one file makes it much easier to communicate design intent too: you can use phasing tools to flip between existing, demo, and new construction views. It’s efficient and requires minimal effort for maximum output.
What sort of complexities are introduced when you construct a building complex in phases?
- What happens at the interfaces between the buildings as the phases advance?
- How can you plan and prepare for these complexities as your create your initial building model?
What are the principal advantages of using a single building information model of the existing conditions as the foundation for modeling several proposed design alternatives for a portion of the building?
- Why not create a separate model for each of the design alternatives?
Using a single BIM model of the existing conditions as the base for several design alternatives keeps everything coordinated and makes iteration seamless while helping clients and contractors stay engaged in the process. For example, if for this project I wanted to present 3 design options to the client for their input, the design is purely the only thing that is different between the models- ensuring the client and/or contractor(s) are not hung up with differences in exisiting systems and/or geometries that I might accidentally model differently if I used multiple re-made models. This ensures consistency in the components of the model that need to be consistent. (E.g., using a different wall assembly accidentally in a new file, confusing the client by causing them to think that is part of the remodel). It is also much quicker to build upon an existing file, especially if you are creating multiple iterations or options of a remodeled design. (Imagine doing this assignment 3 or more times without a starter file….)
In your project, which features of the proposed design did you choose to model as design alternatives?
- Why did you choose these building features? And what were the biggest challenges in modeling them as the design alternatives?