It really is not that hard.
These type of facades tend to have a lot of repetitive details, so practically you only need to model a couple of them.
Use walls, beams, complex profiles, shells, morphs and objects to model the details. SEO are really useful in some details.
When possible, keep the model as parametric and simple as you can; meaning that you should try to keep original tools (walls, beams, etc) in the model in case you need to adjust something; for instance... if some windows are different sizes it pays off to have simple elements that you can stretch.