To be true it’s quite a vague question with an endless amount of answers.
Ladybug/Honeybee provide some nice tools for solar/radiation analysis. Also for comfort etc. you can use for optimizations. Direction/openings and so on.
There are also ways to optimize room arrangements and so on, but I would say, that’s something better done by hand. I know about my former professor, that he created a program for while studying and sold it to a company. They can do now the one millionth office building, optimized for the ground plan, but looking all the same.
In general, I would say, geometrically you can do with grasshopper whatever you want, No limits. But in my opinion, your main tool should be the optimization. There are many examples around the forum about radiation, but also about cost-effectiveness etc.