I took the liberty of tracing a few lines and correcting a few things I saw as problematic with your drawing.
For the size of this drawing, your vanishing points are extremely close. This means that the topmost part (the roof) is outside of the zone where perspective lines would meet at a 90deg angle. This makes the distortion extremely awkward and hard to manage because as you draw the construction boxes, they won't look "right". I created a few construction lines on the roof and the roof you drew does not add up to the vanishing points you set.
Second of all, once you've got boxes in place (such as the main body of the building), create diagonals to find the center of these boxes. This allows you to find the middle and space out details with great accuracy. An example of this (in orange) are the windows you placed, and that center beam, which does not line up with the true center of the box.
Hope it's not too much to handle! I recommend trying another building with either vanishing points that are further apart, or simply shorter as to remain within that 90deg. magic zone.