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?
I think the principal advantages of using a single building information model of the existing conditions as a foundation for other alternatives because making the "set" allows the designer to know exactly what they plan on changing. Then, if one set changes, the others will stay the same. If someone were to copy and paste and then change the options, the rest of the building not part of the set may be changed. All in all, it is better organized to create these design sets and then different options under them. The fact that "primary" exists allows us to show the one we are trying to push more too!
In your project, which features of the proposed design did you choose to model as design alternatives?
I chose the walls as alternatives as I figured sustainable options often include white roofs or green roofs. I took the roof options and decided to add more interior wall details such as living walls (walls with plants on them) to the green roof option and then making the white roof also have white walls. To make it have the highest albedo, I got rid of the windows. Although not as realistic, I think the albedo building would be really cold.