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?
This can be useful if certain elements/materials need to be carried over. Additionally, if the elements are connected in any sort of way, it's important to make sure that they line up. - I think this if from Caitlin's response
I agree with Caitlin's points and I would like to add that it is simply good to not waste time setting up the correct topography, height limit, and other site characteristics in a brand new model. Using a single model onto which additions are added is also good in the way that the model more closely mimics the reality of building and construction, giving workers and designers a better sense of the way old and new fit together (and how they may need to work around it) as opposed to having two separate models with less certainty regarding how they actually look and interact with one another.
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?
As a practical matter of data and space, having one model where most of the elements are relatively the same and only change one portion of the building saves a lot of memory space which, for bigger projects, is going to be huge for being able to easily transfer and collaboratively work with those files. Creating separate models, particularly large projects may be too data intensive to be practical.
Having it all in in one model also allows you to mix alternatives such as different facades with different furniture combinations, etc. That would be difficult to do with just making separate files and would lead to multitudes of combinations that would further compound the issue of file size and abundance given limited storage (ex: 2 different facade options with 3 different interior options with 2 different furniture options gives us 12 unique options- making 12 separate files to show these 12 options is simply not an efficient use of space)