I hear this a lot of time. Many beginners say that they can't draw buildings or scenes because they don't know perspective.
Perspective is a very helpful tool for sketching. But you don't have to use perspective to make a good sketch on location. This video will show you why.
Perspective is just a set of rules that you can use to draw subjects such that they look believable in 3-dimensional space. It's very useful when you're drawing from imagination, e.g. such an architecture rendering of a house.
When it comes to drawing from location, what's more important is your observational skills, and your focus on proportion for each subject in your scene. When you're drawing from observation, the subject is already there in front, and you should draw what you see, not create something from imagination using perspective.
Perspective is a good tool you can use to check your drawing after it has been done, or while you're drawing. You check if the lines are going to the vanishing point, whether the human figures in your scene look believable, e.g. they become smaller as they are standing further away. Or you can use perspective to choose a scene before you even start drawing. E.g. If you want to see more of one side of the building, move away from that side. You can't see how tall the Eiffel Tower is (compared to other buildings) if you're under it or too close.