How would you make this sentence active?

A grammar checker is saying this sentence is passive:

When building a house, for example, you use a symbol for a door instead of drawing a detailed picture of the exact door you want, knowing details like that will be figured out later (probably after quite a few arguments).

I’m trying to keep a very casual tone for a very technical topic. "be figured" reads fine to me. I’m unable to come up with something I like better. I’m stumped. Anyone suggestions?

thanks